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Loop vibes

Printed From: guzziriders.org - moto guzzi forum
Category: Technical
Forum Name: Loop Frames
Forum Description: Anything about the original Guzzi V Twin.
URL: http://www.guzziriders.org/forum_posts.asp?TID=8668
Printed Date: 20 May 2019 at 23:34
Software Version: Web Wiz Forums 12.00 - http://www.webwizforums.com


Topic: Loop vibes
Posted By: Simmoto
Subject: Loop vibes
Date Posted: 19 Apr 2018 at 17:51
So before I start wasting even more time tinkering in the riding season....are Loop (Eldo) vibes through the boards normal. i am talking about the tingling vibes that leave your feet with pins and needles. Not much through the bars at all and mostly at higher revs. Normal or not? I think its always been like this in my short ownership. Possible candidates? The HT circuit is newish and timing is good, carbs are balanced. Only slightly odd noise is from the front - possibly the generator pulley or nuts could be or might have been rubbing....I'm experimenting. Belt is on its loosest setting with no shims visible at the front....,maybe it's slipping? MoT said rear wheel bearings slight free play - doubt this is relevant...

Any knowledge gratefully accepted :-)

Cheers







Replies:
Posted By: Mike H
Date Posted: 19 Apr 2018 at 18:02
Ignition timing might be a gnat's too advanced?


Question for the x'perts: not sure about loops but do they vibrate in the footboard / footrest region if the universal joint is failing? (Tonti's do)

-


-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Simmoto
Date Posted: 19 Apr 2018 at 18:25
Ta Mike, a good thought, I can check the timing again...


Posted By: Dave P.
Date Posted: 19 Apr 2018 at 23:49
Originally posted by Mike H Mike H wrote:

Ignition timing might be a gnat's too advanced?


Question for the x'perts: not sure about loops but do they vibrate in the footboard / footrest region if the universal joint is failing? (Tonti's do)

-

Yes, Loops do too.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Simmoto
Date Posted: 20 Apr 2018 at 06:08
if that's the case it'll get worse or fail so no action. I think it's unlikely as gearbox rebuilt by Mark Etheridge not long ago and vibes on both sides equally not more on the right. 

I did static timing last night; dynamic harder as no rev counter




Posted By: ranton_rambler
Date Posted: 20 Apr 2018 at 06:22
Have you checked generator bracket? They can crack or the fixings can come loose. I've had both, and it does cause vibration.
This Old Tractor has some fixes.
Ian


Posted By: Simmoto
Date Posted: 20 Apr 2018 at 07:51
thanks, yes I went over the bike in the winter and it seems well anchored.  I guess it could be generator bearings. Also need to ride it without the belt cover on to make sure no fouling as there are marks inside. Could it be clutch? PO changed it. 

Just rode it to work, about 30 miles,  great at 45-50 mph in 5th but gets progressively more tingly vibes as you go faster

It might be just how it is. It has floorboards and they are not isolated at all but bolted to the front and rear engine/box mounting bolts so will directly transmit vibes to my boots. 


Posted By: Dave P.
Date Posted: 20 Apr 2018 at 13:09
Have you checked the two engine/gearbox mounting bolts?

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Simmoto
Date Posted: 20 Apr 2018 at 14:03
thanks, yes they are well torqued up


Posted By: jmee54
Date Posted: 20 Apr 2018 at 16:50
I never experienced vibes. That is a bit of a worry. I changed the UJ and bearing, but just the actual centre cross of the UJ though. The fit into the bearing was not a tight interference fit, and questions online said it was normal and to use some bearing locktite, which I did. Before that I rode around France and Belgium (1500 miles) and suffered no vibrations at all. My riding after was mainly local ish, up to 100 miles and then back and I don't recall anything untoward. The UJ is the only thing that comes to mind, as anything that I changed that could possibly be a problem. Not a loose exhaust, or something in the vicinity loose?


Posted By: Simmoto
Date Posted: 20 Apr 2018 at 18:52
Hi feels to me electrical maybe capacitor is duff, who knows? Thanks for taking the time to think about it. Good to know about the UJ work


Posted By: Mike H
Date Posted: 20 Apr 2018 at 19:48
Originally posted by Simmoto Simmoto wrote:

It might be just how it is. It has floorboards and they are not isolated at all but bolted to the front and rear engine/box mounting bolts so will directly transmit vibes to my boots. 


Yeah but no but, what jmee said, I never had vibrations thru the boots either - albeit we're talking footrests not boards, but are still solidly attached to the frame - except in one case, when there was a problem. What this was became apparent in due course, when the UJ literally exploded. (Seriously. I was wondering what is this bluddy vibration I keep getting, then bang ...)

Ouch


I would have swing arm off for a coating of looking at...

HTH




-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Brian UK
Date Posted: 20 Apr 2018 at 20:43
I remember that sort of thing when riding my Norton Commando. Heard a rattle, bent down to check if the exhaust pipe clamps were still tight, and Bang, big hole in the crankcase and half a con rod sticking out.
Moral of the story????


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Simmoto
Date Posted: 20 Apr 2018 at 21:43
So if I put it on the main stand rev in neutral and vibes are still there it can't be the driveshaft...


Posted By: Brian UK
Date Posted: 20 Apr 2018 at 22:48
That should be the case.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Dave P.
Date Posted: 21 Apr 2018 at 09:58
You could try running it without the dynamo belt,just to eliminate dynamo bearing problems.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Simmoto
Date Posted: 22 Apr 2018 at 11:23
Thanks, yes agreed. Not much time on it this w/e but I did rev it in neutral on the mainstand and its very vibey; my feet are tingling as I write ;-) I have checked exhaust is tight and not contacting the chassis etc. So next i'll disconnect the pulley belt and see what happens. Good that it seems unlikely to be the UJ.
Cheers





Posted By: Simmoto
Date Posted: 22 Apr 2018 at 13:57
Took the dynamo belt off, no change. Fiddled with HT leads, changed the plugs. No change.
So lets say its on the ignition HT side, what are the options?

- I'm not setting the timing correctly. Possible but doing it by the book, LHS cylinder on compression stroke at third mark on lower pulley, then move dizzy using a timing light to detect points opening
- Would points gap make a difference if that was incorrect? Points are new. Easy to check again so i'll do that.
- Capacitor is duff (its a new Bosch one)
- Distributor cap has a hairline crack? Can't see anything wrong with it
- Coil is suspect - it's new
- Plug caps are wrong resistance or similar (also new) What should they be? I thought I bought black NGKs of correct spec
- Coil feed to distributor on wrong terminal? Would the thing work if this was the case? Have to take off tank to look
- Dodgy connection/wiring somewhere....
- Rotor arm is duff - it's old

Anything else other than imminent engine death?
Ta





Posted By: Loopian
Date Posted: 22 Apr 2018 at 17:03
I’ve just tuned my loop and I do the following in this order. Valves, spark plugs, points set gap and make sure to remove pitting and I can only do this by removing points to visually check. Ignition timing with a xenon strobe light which is explained in the shade tree mechanic guide on Greg’s site. Then finally I balance and sync the carbs with a Morgan Carbtune which is also explained on Greg’s site in an article by Patrick Haynes.  I spend time getting all the above spot on and the bike starts quick and runs very smooth after a good tune and very satisfying to do. I’m sure seasoned mechanics don’t need the Carbtune or xenon strobe light but for me it works, so it might be worth considering.
Good luck Ian








Posted By: Brian UK
Date Posted: 22 Apr 2018 at 17:54
You have one set of points and a distributor, yes?

So you have two cams on the rotor to open the points, and you set it on the left one.

Have you checked the timing on the right? Just that with wear or slack on the rotor/shaft, you could get a variation between pots.

A strobe is always the best way, it will show up any discrepancy at higher revs.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Dave P.
Date Posted: 22 Apr 2018 at 18:13
Checked all nuts attaching gearbox to the engine are tight?? And indeed all nuts and bolts all over the bike are tight.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Simmoto
Date Posted: 22 Apr 2018 at 18:40
Yeah thansk for all that guys, will double check points/lobes Brian, other stuff I've done as described by Loopian except dynamic timing - this is because you need a rev counter to do it adn mine doesn't have one...no marks on the flywheel on this age of machine.

Ah well, been for a ride, goes really well, just stay at 55 or below and its a lovely ride


Posted By: Brian UK
Date Posted: 22 Apr 2018 at 18:47
You don't need a rev counter, but you do need a timing disc.

With points, everything over 3k rpm is advanced.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Mike H
Date Posted: 23 Apr 2018 at 00:08
Has it always done this or something that's started recently?




-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Dave P.
Date Posted: 23 Apr 2018 at 05:39
Is yours a very late Loop with a cam chain by any chance?If so, could a maladjusted chain or damaged tensioner be the cause?
Another thought,is your advance/retard device working properly? No broken or weak springs allowing it to advance too early, or wear, allowing it to advance too far?
I can't think of any more straws to grasp at.


-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 06:45
don't know if it's always like it, PO says not and I am a picky sod...
Good point Dave it's a 73 so on the cusp, how do you tell if it's chain or gears be interesting to know regardless.

I'm going to change the HT leads and caps for better ones





Posted By: cyclobutch
Date Posted: 23 Apr 2018 at 12:33
Sounds like you need to compare notes with someone else with a bike of similar vintage. Mine starts with quite a clatter but runs pretty smooth - though maybe that view is lensed through some of the other more awful things I get to ride.

If there is a more fundamental area within the engine/transmission beginning to break I would expect that to deteriorate quite quickly.


-------------
Butch
V50 II - 'The Black Pearl'
T3 - 'Blue'
Eldo Loop - 'Jug'


Posted By: ranton_rambler
Date Posted: 23 Apr 2018 at 12:47
Originally posted by Simmoto Simmoto wrote:

don't know if it's always like it, PO says not and I am a picky sod...
Good point Dave it's a 73 so on the cusp, how do you tell if it's chain or gears be interesting to know regardless.

I'm going to change the HT leads and caps for better ones



Guzziology has the engine number when it changed. I'll try and look it up if I remember.
Ian


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 13:07
thanks Ian I have a copy so no worries, appreciate it


Posted By: Loopian
Date Posted: 23 Apr 2018 at 14:00
When I first got my v750 (1971) and rode it home about a 70 mile journey it did seem to shake a bit at speed to the extent that I thought that I’d keep off any fast roads. So I gave it a tune where the timing (dynamic) and carbs needed considerable adjustment, I put on some new tyres and got the pressures right. I can now cruise happily at 70+ with perfect vision in the mirrors, and I’m sure the engine seems to smooth out above 3500 revs. I can’t imagine that the 850 should be much different.  They really are a great bike to ride so hopefully you will find out what’s up soon.
Cheers Ian


Posted By: Amboman
Date Posted: 23 Apr 2018 at 14:31
For US models, the timing chain started with engine number 58532. The timing cover is slightly different on timing chain engines: once you remove the belt cover, you can see whether the "bump" to clear the oil pump nut is small (gears) or larger (chain).


-------------
Charlie
'69 V700, '69 Ambassador, '76 Convert, '85 Morini 350 K2
http://www.AntietamClassicCycle.com


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 14:47
how do you do your dynamic timing Ian? As per shade tree mechanic? If so how do you judge RPM.?


Posted By: Dave P.
Date Posted: 23 Apr 2018 at 15:22
Originally posted by Amboman Amboman wrote:

For US models, the timing chain started with engine number 58532. The timing cover is slightly different on timing chain engines: once you remove the belt cover, you can see whether the "bump" to clear the oil pump nut is small (gears) or larger (chain).


You learn something new every day!

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Mike H
Date Posted: 23 Apr 2018 at 16:43
Originally posted by Simmoto Simmoto wrote:

don't know if it's always like it, PO says not and I am a picky sod...


LOL I should have phrased the question differently LOL

So it has been like that all the time you've had it?

So not, you changed something, then got vibration...



-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 17:36
Originally posted by Amboman Amboman wrote:

For US models, the timing chain started with engine number 58532. The timing cover is slightly different on timing chain engines: once you remove the belt cover, you can see whether the "bump" to clear the oil pump nut is small (gears) or larger (chain).

Excellent, thanks Charlie so mine has a chain as it starts with a '6'. Could explain vibes I guess and some unusual noises from the front


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 17:38
Originally posted by Mike H Mike H wrote:

Originally posted by Simmoto Simmoto wrote:

don't know if it's always like it, PO says not and I am a picky sod...


LOL I should have phrased the question differently LOL

So it has been like that all the time you've had it?

So not, you changed something, then got vibration...


The truth is I don't know - i don't remember it being vibey but as I've got more used to the bike, worked on it and have a bit of faith in its abilities so I've pushed it a bit faster....I've done a lot of things to it over the winter so it's a complex algorithm :-)


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 18:09
So I guess the question is whether an Eldo with a chain/tensioner/cogs in good condition would cause some vibes or do vibes indicate wear? There's no rattle as such but the vibes are worst at the front of the floorboards suggesting maybe come from front of the engine...

Either way I wont do the work as it's exactly the sort of job I'd make a pigs ear of, probably wait until winter...


Posted By: Amboman
Date Posted: 23 Apr 2018 at 18:33
"Unusual noises" could be the slack timing chain grinding away at the engine case and timing cover. The plastic?/rubber? block on earlier tensioners has a bad habit of disintegrating and then the bits flow throughout the engine - I've found them in the rocker pins.

The slack chain plays havoc with both the valve and ignition timing, this could make a significant difference in how well the engine runs.




-------------
Charlie
'69 V700, '69 Ambassador, '76 Convert, '85 Morini 350 K2
http://www.AntietamClassicCycle.com


Posted By: Dave P.
Date Posted: 23 Apr 2018 at 18:52
Would it be impertinent to suggest that the time is now!!

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Loopian
Date Posted: 23 Apr 2018 at 18:53
Originally posted by Simmoto Simmoto wrote:

how do you do your dynamic timing Ian? As per shade tree mechanic? If so how do you judge RPM.?
Well yes I do it as per shade tree mechanic however I’ve got a rev counter which makes it easy for me. I wonder if you could you use some sort of multimeter to check the revs. I do know that I first set up the timing using the static method I then got hold of a strobe and used the dynamic method there was quite a difference in the distributor position. Unfortunately I did not run the bike inbetween so I can’t tell what difference it made. However the full tune up definitely made the bike run very well.
Cheers Ian


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 19:11
Originally posted by Dave P. Dave P. wrote:

Would it be impertinent to suggest that the time is now!!

Could be or could be a red herring.... I need to listen more carefully...if there was a decent place in Scotland that could do the work I'd have it done today...
 




Posted By: Simmoto
Date Posted: 23 Apr 2018 at 19:13
Originally posted by Amboman Amboman wrote:

"Unusual noises" could be the slack timing chain grinding away at the engine case and timing cover. The plastic?/rubber? block on earlier tensioners has a bad habit of disintegrating and then the bits flow throughout the engine - I've found them in the rocker pins.

The slack chain plays havoc with both the valve and ignition timing, this could make a significant difference in how well the engine runs.



Yeah for sure, I'll get a screwdriver and have a good listen


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 19:53
Can I change an Eldorado from timing chain to gears? I see Harper Moto do kits for other models but exclude the Eldo...?


Posted By: Dave P.
Date Posted: 23 Apr 2018 at 20:18
https://www.harpermoto.com/gear-set-13071700.html" rel="nofollow - https://www.harpermoto.com/gear-set-13071700.html
This set from Harpers is for an Eldorado.It is listed in their general listing of Eldorado spares.I have no idea if you can just do a straight swop with the sprockets.Perhaps Charlie (Ambo Man) can advise.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 20:25
Thanks for that Dave, I'm sure I've read about this somewhere but can't for the life of me find in the usual places...


Posted By: Dave P.
Date Posted: 23 Apr 2018 at 20:32
There's quite a bit on the net about changing from chains to gears on later models but not much (if anything)on Loops. because most Loops had gears from the start.I'm fascinated by this thread because I have such a high regard for Loops and really want to know the cause of your problem.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: jmee54
Date Posted: 23 Apr 2018 at 20:40
Mark Etheridge went through the engine too. He replaced anything that needed attention at the time, I believe.

"Here I have for sale a 1973 Moto Guzzi Eldorado Police that has matching Vin and Engine numbers. I bought it about three months ago from Mark of Moto Guzzi Classics, He replaced Cylinders, Rings and gaskets, also replaced Front Main, Rear main Seals, and rebuilt the Transmission. The Forks seals and oil were replaced to give it a smooth ride, also the Main Drive seal and oil were also replaced along with the Battery, Seat, Front and rear Crash Bars. This Guzzi has new Paint, Pin Stripes and Decals. Everything that could be Polished has been done as you can see from the pics it looks great, the Carbs were also rebuilt, Replaced oil pan Gasket and all Bolts were replaced with Stainless Steel, Replaced Electric Switches with original ones, It also has Dietz signal lights that are original to the bike, New Floorboards and Police Kick Stand. You can ride this Guzzi Home or International Bidders I would be willing to deliver to a shipper at no extra charge. These Guzzi's are getting harder to find in this Condition so don't miss out, I have sold Guzzi's before but nothing this nice even the Chrome on the Tank is like New, All the Lights on the Dash work you can come by Long Beach and see it for yourself or watch the Video I posted on YOUTUBE under 1973 Black Moto Guzzi Eldorado Police and see and hear it run. I reserve the right to end the Auction at any time but take great pride in my Feedback so bid with confidence, and if you have any questions call me at 562-440- or message me thru Ebay. Thanks for looking have a nice day!!! 
I forgot to mention that Clutch, Clutch Cable and Front Brake Cable were also replaced. Tires have about 80% left."


I hope it turns out to be something simple and cheap to sort.






Posted By: Simmoto
Date Posted: 23 Apr 2018 at 20:50
Thanks Jmee, yes I have a copy of the list of work and went through it, it doesn't mention timing chest so I assume it was fine then - and may be now, I will shine a strobe at it to see if timing skips around and have a listen to the timing chest - it may all be fine. Either way not your problem, I am delighted with the bike, but any old machine needs some work! :-)
Cheers  


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 20:53
Originally posted by Dave P. Dave P. wrote:

There's quite a bit on the net about changing from chains to gears on later models but not much (if anything)on Loops. because most Loops had gears from the start.I'm fascinated by this thread because I have such a high regard for Loops and really want to know the cause of your problem.

Going back to my original post it may be normal - interestingly Nick Adams who rides large distances on his Eldo (with gears) and Convert (with chain) notes he gets some vibes through the boards of the Convert...:-)



Posted By: jmee54
Date Posted: 23 Apr 2018 at 21:31
It's hard not to feel somewhat responsible when you sell a vehicle if something goes pear shaped. I hope things get sorted and it is something simple.


Posted By: Simmoto
Date Posted: 23 Apr 2018 at 21:37
Guzziology says you can fit gears but it's complicated and not worth the effort vs new chain and tensioner


Posted By: ranton_rambler
Date Posted: 24 Apr 2018 at 12:49
Going back to timing,
I use a strobe to set mine, but I ignore the idle/static setting on the basis that the motor spends most of its time running at higher speed. I therefore make sure I get the timing right at full advance. My bike is an 850GT so has a rev counter but I can't see it when I'm looking at the pulley. All I do is wind the throttle round until the marks stabilise.

Like someone else, I was riding mine at the weekend and was very conscious of vibration through the pegs. There is some, but not what I would consider excessive. Maybe depends what you're used to? I've done 400 mile days on it and not suffered from pins and needles in my feet, but it does have certain speeds it feels nicer at. 60-65mph is quite nice, but overall probably smoothest above 80mph.


Posted By: Simmoto
Date Posted: 24 Apr 2018 at 13:05
Thanks, yes so progress today. I duly painted the marks on the bottom pulley and did as you've described and Brian suggested - just went to full advance with the strobe on it. It was slightly retarded (somewhat like its owner) so I fiddled with the distributor and it is now spot on. Still tingles but less and I now think it is very nearly as good as I can get it - which is bloody good and a bit tingly. 

There was almost no ghosting so I think the chain and tensioner are fine - borne out by listening with a screwdriver to the chaincase and revving it; no rattle at all. There is still on odd noise, I think from the front but not sure what - it is only audible when riding so I'm just going to live with it.

Although I didn't use it I downloaded a free App to my phone that turns its torch into an adjustable strobe and then converts that to RPM; you adjust the strobe until the spinning object appears to be still and that's your RPM - neat. Wanted to give it a go but engine was getting hot..so for another day.

Thanks All
Cheers 


Posted By: Amboman
Date Posted: 24 Apr 2018 at 14:09
Originally posted by Dave P. Dave P. wrote:

https://www.harpermoto.com/gear-set-13071700.html" rel="nofollow - https://www.harpermoto.com/gear-set-13071700.html
This set from Harpers is for an Eldorado.It is listed in their general listing of Eldorado spares.I have no idea if you can just do a straight swop with the sprockets.Perhaps Charlie (Ambo Man) can advise.


The oil pump and it's position are both different in timing chain engines vs. timing gear engines, so it wouldn't be an easy swap.


-------------
Charlie
'69 V700, '69 Ambassador, '76 Convert, '85 Morini 350 K2
http://www.AntietamClassicCycle.com


Posted By: jmee54
Date Posted: 24 Apr 2018 at 14:25
Have you still got the screen on? That does tend to amplify noises that you can only hear when riding.

J.


Posted By: Dave P.
Date Posted: 24 Apr 2018 at 16:17
Thanks, Charlie.That's something else we've learned.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Mike H
Date Posted: 24 Apr 2018 at 16:20
Originally posted by Dave P. Dave P. wrote:

and really want to know the cause of your problem.






-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Simmoto
Date Posted: 24 Apr 2018 at 19:26
Originally posted by jmee54 jmee54 wrote:

Have you still got the screen on? That does tend to amplify noises that you can only hear when riding.

J.
No The screen is off Jmee.


Posted By: Simmoto
Date Posted: 24 Apr 2018 at 19:41
Originally posted by Mike H Mike H wrote:

Originally posted by Dave P. Dave P. wrote:

and really want to know the cause of your problem.





So the answer to that is there isn't a problem. The bike has some vibes at higher revs but there's no obvious mechanical cause, just resonance I suppose. Need to ride it now and see how it feels, if I need to I'll look into isolating the front boards where they attach to the engine bolt using doughty washers or similar - or wear beeltecrushers...


Posted By: Brian UK
Date Posted: 24 Apr 2018 at 20:03
Or just add a bit of weight to them and alter the resonant frequency.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: kateguy
Date Posted: 25 Apr 2018 at 08:23
Leave it at that and get a good set of Gel insoles for yer boots...and no..I aint jokin...

-------------
Moto Guzzi Club GB.....
850 LE MANS...1 & 2....V7 Loop Frame..V7 Sport replica...Guzzi Daytona...Ducati 900ss Bevel not belt.....Laverda 3C ....and an MZ...


Posted By: cyclobutch
Date Posted: 25 Apr 2018 at 08:37
Got me worrying now that mine doesn't vibe enough. Or maybe I'm just an insensitive fool? (Mrs B's kind words).

Mind you, I am using a rigid mount Sportster for my daily commute to the station at the moment.


-------------
Butch
V50 II - 'The Black Pearl'
T3 - 'Blue'
Eldo Loop - 'Jug'


Posted By: Simmoto
Date Posted: 25 Apr 2018 at 09:03
yeah I mean I'm no stranger to vibes, Norton Big 4 shook you senseless, it was just the frequency of vibes that made my feet numb and tingly but less so now


Posted By: jmee54
Date Posted: 25 Apr 2018 at 12:33
Just been reading a post on the Yahoo site which has given me cause for concern.

As I said, when I replaced the bearing and UJ, there was not a tight fit  of the UJ into the bearing. It wasn't sloppy, but not a tight interference fit. I used bearing loctite, as recommended on the web.

Now having asked the question of what happens if it comes loose again on the Yahoo site, this is the answer.

"
If left to spin, it will wear the u-joint yoke 'snout' until it starts to oscillate as the load rapidly shifts while its spinning. Eventually, you'll feel this as vibration mostly in the RH footpeg. Eventually it would I assume cause the cross bearings to fail, but all the ones I've seen that were loose were caught before that happened because the vibration became a "uh-oh .................... something ain't right" situation.

It's easy to check - just loosen the forward UJ boot hose clamp and stick a screw driver in there and see if you can move the UJ forward & aft. You shouldn't be able to. If you can, order a UJ / bearing / clip kit. After it arrived make yourself a pot of powerful coffee and start dismantling. You'll need a press BTW to get the carrier bearing out then back in."

I am now wondering if this could be the cause of your vibration, and again feeling a sense of unease. J
__._,_.___


Posted By: cyclobutch
Date Posted: 25 Apr 2018 at 12:41
Hmmmmm. I've always used Loctite on the loose one's I've had as an act of faith, never sure whether it would really work or not. I mostly look at these annually and the following year on disassembly it's never been clear to me whether this actually lasted for the duration or not. 

I've never encountered one that was worse than a light sliding fit i.e. not in any way sloppy or floppy (p51ck in a shirt sleeve as my old man would have said). And I've never witnessed one getting any worse year on year.
In the subject case here I'd be tempted to go have a peer on this basis though. And despite pulling the back out of a big twin, Loop or Tonti, being one of my least favourite jobs.


-------------
Butch
V50 II - 'The Black Pearl'
T3 - 'Blue'
Eldo Loop - 'Jug'


Posted By: Simmoto
Date Posted: 25 Apr 2018 at 13:32
thanks Jmee and Cyclobutch for the thoughts; certainly worth an inspection on a rolling basis. It is not the cause in this case as vibes are both equal sided, from the front and critically are present when in neutral and on the main stand.
Cheers


Posted By: Mike H
Date Posted: 26 Apr 2018 at 19:17
Originally posted by jmee54 jmee54 wrote:

If left to spin, it will wear the u-joint yoke 'snout' until it starts to oscillate as the load rapidly shifts while its spinning. Eventually, you'll feel this as vibration mostly in the RH footpeg. Eventually it would I assume cause the cross bearings to fail,


On mine (abeit Tonti frame) the amount of "oscillation" (aka, sideways & up-and-down movement) allowed the UJ to rub the inside of the tunnel and wear itself away until one of the needle roller bearings fell out.



Originally posted by cyclobutch cyclobutch wrote:

Hmmmmm. I've always used Loctite on the loose one's I've had as an act of faith, never sure whether it would really work or not. I mostly look at these annually and the following year on disassembly it's never been clear to me whether this actually lasted for the duration or not.

I think it works for awhile, just not for long. I.e. temp fix.

Longer term repair is replace both bearing and UJ with new.




-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Simmoto
Date Posted: 27 Apr 2018 at 10:36
Originally posted by kateguy kateguy wrote:

Leave it at that and get a good set of Gel insoles for yer boots...and no..I aint jokin...

Beer



Posted By: Simmoto
Date Posted: 27 Apr 2018 at 10:37
Originally posted by jmee54 jmee54 wrote:

Just been reading a post on the Yahoo site which has given me cause for concern.

As I said, when I replaced the bearing and UJ, there was not a tight fit  of the UJ into the bearing. It wasn't sloppy, but not a tight interference fit. I used bearing loctite, as recommended on the web.

Now having asked the question of what happens if it comes loose again on the Yahoo site, this is the answer.

"
If left to spin, it will wear the u-joint yoke 'snout' until it starts to oscillate as the load rapidly shifts while its spinning. Eventually, you'll feel this as vibration mostly in the RH footpeg. Eventually it would I assume cause the cross bearings to fail, but all the ones I've seen that were loose were caught before that happened because the vibration became a "uh-oh .................... something ain't right" situation.

It's easy to check - just loosen the forward UJ boot hose clamp and stick a screw driver in there and see if you can move the UJ forward & aft. You shouldn't be able to. If you can, order a UJ / bearing / clip kit. After it arrived make yourself a pot of powerful coffee and start dismantling. You'll need a press BTW to get the carrier bearing out then back in."

I am now wondering if this could be the cause of your vibration, and again feeling a sense of unease. J
__._,_.___

To put yr mind at rest Jmee I took the fwd boot off, stuck in a screwdriver and wiggled - zero movement.
Cheers


Posted By: Simmoto
Date Posted: 07 May 2018 at 21:12
Had a good run this weekend and the vibes seemed to increase so I stripped down the front to inspect the timing chain and tensioner. the rubber block type tensioner is nowhere near the cain which has about 1cm of slack. I'm going to try and adjust it but if not will replace the chain and mayne an updated tensioner (lots about them on t'web). 

So, to those who said it's your chain,  I say spot on and thank you!

Cheers



Posted By: Mike H
Date Posted: 09 May 2018 at 02:32
if the block can’t be made to reach the chain then It means the chain is worn out. It doesn’t mean put a different design tensioner on so that they can be made to touch. 

Still not personally convinced this is source of vibration though but could be. 



-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: johnno
Date Posted: 09 May 2018 at 08:32
when my timing chain went on T5 the noise just appeared and there was no doubt what the cause so I tend to think Mike could be right . hope it's sorted soon for you

-------------
GSXR1100 L ,Moto Guzzi .750xpa,.1100 sport,1100 sport corsa rider


Posted By: Simmoto
Date Posted: 09 May 2018 at 08:41
Yes my initial enthusiasm at finding something obviously wrong has been tempered...but it is an issue and on close inspection the chain is goosed so replacing it and tensioner and then see where we are. Cheers


Posted By: Dave P.
Date Posted: 09 May 2018 at 15:20
Not forgetting that your cam and ignition timing will have been affected. How much vibration that would cause I don't know, but some I suspect.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Mike H
Date Posted: 09 May 2018 at 20:57
I seem to remember hearing or reading that in the early days some bike shops wanted to avoid looking at this much less replacing due to the aggro of getting the front cover off, possibly spawning an urban legend that they last forever and don’t need checking.  



-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: jmee54
Date Posted: 09 May 2018 at 21:32
Blimey! I never looked in there, that is something I didn't expect.


Posted By: Simmoto
Date Posted: 10 May 2018 at 10:10
yeah it's not the most easily accessible bit of the bike! Might be a red herring but we'll see; certainly there is a lot of slack and front to back movement of the chain so well shot 


Posted By: Simmoto
Date Posted: 22 May 2018 at 19:39
So i got the old chain off, and the sprockets and put the new chain and a spring tensioner on - took me a while to mull it all over and settle on a plan; I was going to split the endless new chain and add a link to avoid taking the sprockets off but decided to bite the bullet in the end - it wasn't so bad, just a confidence thing as its not something I'd messed with before. A fiddle of a job though, putting them on as a set with chain in place takes a few attempts. i remain skeptical about the longevity of the spring tensioner but we'll see I guess.

Have only had a short test run and the throttle is quicker to respond and she ticks over more evenly. Not sure about the vibes, need to go for a decent run. Pics below; 

Old


New and new close-up showing all important alignment marks






Posted By: red leader one
Date Posted: 22 May 2018 at 21:13
That's a big chain.


Posted By: Mike H
Date Posted: 25 May 2018 at 13:32
I see you have changed to that sprung slipper type tensioner; not wishing to rain on your parade but that one has a bit of a reputation for getting chewed up, or I think in one case the spring broke. Unless they have improved lately.

Personally I would stick with the stock rubber block, all it has to do is prevent the chain flapping about, but YMMV.





-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Amboman
Date Posted: 25 May 2018 at 14:28
Originally posted by Mike H Mike H wrote:

I see you have changed to that sprung slipper type tensioner; not wishing to rain on your parade but that one has a bit of a reputation for getting chewed up, or I think in one case the spring broke. Unless they have improved lately.

Personally I would stick with the stock rubber block, all it has to do is prevent the chain flapping about, but YMMV.





I've only seen one instance where the spring broke. One engine that I opened up had 50k miles on that type of tensioner and there was just the faintest marking on the "shoe", not even what you could call a groove.


-------------
Charlie
'69 V700, '69 Ambassador, '76 Convert, '85 Morini 350 K2
http://www.AntietamClassicCycle.com


Posted By: Mike H
Date Posted: 25 May 2018 at 15:08
That's fair enough, not all have a problem.



-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Brian UK
Date Posted: 25 May 2018 at 15:32
I had one with a broken spring. The tensioner plastic was also twisted out of shape as a result. Found the bits of spring in the bottom of the timing chest. When I enquired at the time, several others said they had suffered the same problem.

It is possible the spring has been improved since then.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Dave P.
Date Posted: 25 May 2018 at 15:48
I believe that particles of the original type rubber block are sometimes found in the rocker spindle oil ways. Not a good recommendation for retaining the original set up.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Mike H
Date Posted: 25 May 2018 at 16:09
Only if the block is too tight, which it mustn't be. Which is why I said all it needs to do is stop the chain moving about too much. Haynes says the procedure is to push the block across to touch the chain, then rotate crank to find the tightest spot in the chain run between cam and pump sprockets, when block is relocated to match, tighten the lock bolts there. Lot of people seem to think the rubber is supposed to act like some sort of tensioner spring which it isn't, not remotely, but that's how you get it chewed up. Should only be a couple of shallow grooves in it even after many miles of use.

HTH

Incidentally, my MG workshop manual says sweet bu55er all about it, and shows only one picture I think of the chain assembled.




-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Simmoto
Date Posted: 25 May 2018 at 16:36
Already rained on my own parade Mike - I said in my post, not convinced of its longevity.

Good to read Charlie's view as he's probably seen orders of magnitude more tensioners than anyone else.


I can't be bothered with a block and the need for adjustment, but the later Guzzi spring tensioner maybe.

Went for a ride today and the tingling vibes are gone :-)

Cheers


Posted By: Mike H
Date Posted: 25 May 2018 at 17:08
A-HA!! Thumbs Up




-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Dave P.
Date Posted: 25 May 2018 at 18:20
Excellent news!! Now go out and enjoy your lovely machine.

-------------
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.


Posted By: Loopian
Date Posted: 26 May 2018 at 10:18
Good news on getting it sorted.  I went for a 150 mile ride through East Sussex and Kent yesterday on my loop, these bikes are good for the soul. 
Cheers Ian


Posted By: Simmoto
Date Posted: 26 May 2018 at 13:10
Thanks Guys! I took her to the Scottish MGGB Club rally couple of weeks ago and will be at the Penine rally too in June - that'll be a good run of 600 miles or so round trip. In the meantime more tweaking and short runs; just adjusted the clutch - what a PITA, that adjuster and locknut are almost impossible to get at!
Cheers


Posted By: Jerry atric
Date Posted: 26 May 2018 at 13:59
Very pleased for you at solving the vibes, i followed this thread with interest


Posted By: Mike H
Date Posted: 28 May 2018 at 17:55
Originally posted by Dave P. Dave P. wrote:

I believe that particles of the original type rubber block are sometimes found in the rocker spindle oil ways. Not a good recommendation for retaining the original set up.

I keep forgetting a loop frame model doesn't have a cartridge filter LOL





-------------
"Chicken nuggets don't dance on a Tuesday."



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