guzziriders.org - moto guzzi forum Homepage
Forum Home Forum Home > Technical > Small Blocks
  New Posts New Posts RSS Feed - Guzzi V7 Stone II - Crazy Start
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Guzzi V7 Stone II - Crazy Start

 Post Reply Post Reply Page  12>
Author
Message
julieng View Drop Down
Guzzino
Guzzino


Joined: 02 Nov 2018
Location: los angeles
Status: Offline
Points: 2
Post Options Post Options   Thanks (0) Thanks(0)   Quote julieng Quote  Post ReplyReply Direct Link To This Post Topic: Guzzi V7 Stone II - Crazy Start
    Posted: 02 Nov 2018 at 20:31
Hi everyone, I am brand new so please tell me if I do anything incorrectly, or if this isn't the right place to post.

I have a 2015 V7 stone II. It s a beauty. But also not the most reliable bike I would say. Or maybe I am just an unlucky owner.

Here is the issue: for the past days, every single time I tried to start the bike, as soon as I press the start button, the engine rages instantly to 7k RPM and stall right after. I can sometime try to maintain the engine turned on by playing gently with the gas, but end up stalling at some point. I also tried to ride it around the block, it s hectic... feels like the gas arrival is irregular and the bike would just stall eventually.

Any idea what this could be and how to fix it? My knowledge of mechanics is as limited as my financial ability, I would say. But I have started to change oil by myself and I would be very happy to try and fix things alone, if not too crazy complex and doable with the average joe tool box.

Thanks in advance for your help, and happy to be part of this community. This is a great forum.
Back to Top
Brian UK View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Surrey
Status: Offline
Points: 9422
Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 02 Nov 2018 at 22:43
Helps if you post in the right section so I've moved it.


Edited by Brian UK - 03 Nov 2018 at 21:10
Brian.

Better 5 minutes late in this world than years early in the next.
Back to Top
BobV7 View Drop Down
Senior Member
Senior Member
Avatar

Joined: 20 Nov 2014
Location: W. Sussex
Status: Offline
Points: 2032
Post Options Post Options   Thanks (0) Thanks(0)   Quote BobV7 Quote  Post ReplyReply Direct Link To This Post Posted: 03 Nov 2018 at 11:56
The only way to diagnose this is to methodically run through the "might be" and cross them off.

Start by checking the throttle cables are not snagging on anything; preferably they should be in a gentle loop without any sharp bends. Then see if the engine revs when you turn the handlebars and if it does then you need to adjust the cables by slacken them off at the handlebars end. There should be a little slack as you open the throttle.

Is there a cold start lever on the left hand switch assembly?  This only holds the throttle slightly open while you first warm the engine up, it doesn't have any effect on the fuel mixture. This should normally be off, that is pushed fully forwards once the engine is warm.

While twisting the throttle have a look at the throttle bodies and see if anything is interfering with them operating. The other thing that occurs to me is that the fuel filter is damaged or blocked. As this is inside the fuel tank it would probably best left to a competent mechanic to check.

Being a simple soul I have no idea if this is could be an electronic problem.
V7 Classic Black and gold is the best colour
Back to Top
jefrs View Drop Down
Senior Member
Senior Member
Avatar

Joined: 12 Aug 2018
Location: West Berkshire
Status: Offline
Points: 278
Post Options Post Options   Thanks (0) Thanks(0)   Quote jefrs Quote  Post ReplyReply Direct Link To This Post Posted: 03 Nov 2018 at 14:47
The 2015 V7 II is twin injector, single throttle body. It does not have a cold start.

The twist grip return cable must shut the throttle body and close the throttle position sensor.
Yes, do check the throttle cables as BobV7 said.  The throttle body on the V7 II is only just visible with the seat off and the tank lifted, even then there is nothing much to see; black box tech.

Cutting out at 7000rpm is probably the rev limiter killing the engine before damage is done. 
Letting any engine rev to that kind of velocity in neutral is a bad thing. Let's hope the limiter did its job and nothing damaged.

Everything is done by the MIU G3 computer, this is worth a read -
(you will probably have to copy and paste the whole URL, it is too long for usual click on it method)

You might try rebooting the ECU by pulling the main 30A fuse to shut it down for about 20 seconds and then replace it. Not sure this will cure the problem but it does clear the "self adaptive matrix" tables.

EFI/ECU can get their knickers in a twist (tr. shorts in a bunch) sometimes and forget where idle speed position is and have to re-learn. This is usually the throttle position sensor calibration but can be almost any sensor, a wire-off (connectors), or mechanical e.g. cables.
There is usually a "recalibrate the throttle position" sequence on a bike but I have yet to find one for the V7 II. Some of these devices force a recalibration when re-booted.
A dealer's Moto Guzzi diagnostic port tools should be able to sort it out.


Edited by jefrs - 03 Nov 2018 at 14:51
Back to Top
Mike H View Drop Down
Senior Member
Senior Member
Avatar

Joined: 21 May 2014
Location: East Anglia
Status: Offline
Points: 5848
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 03 Nov 2018 at 16:36
I'm getting deja vu, hasn't this happened before? Revving like mad then stopping. Can't remember what it was.

Off the top of my head I would think it might be an air leak downstream of the throttle body.




"Chicken nuggets don't dance on a Tuesday."
Back to Top
Andyb View Drop Down
Senior Member
Senior Member
Avatar

Joined: 02 Jul 2016
Location: Nottinghamshire
Status: Offline
Points: 159
Post Options Post Options   Thanks (0) Thanks(0)   Quote Andyb Quote  Post ReplyReply Direct Link To This Post Posted: 03 Nov 2018 at 18:20
Mine did it at 1000 miles..... I rode to work, all OK, then came to start it to ride home and it was difficult to start and then started to rev up.  As soon as the revs rose I killed it.  I tried disconnecting the battery but no change.  The throttle body was replaced under warranty and has been fine the last 3 years.
When the new TB was fitted I had hoped that the rough low speed running might go away but even with an updated map it was still there.....so as has been reported here ab nausia I removed the lambdas which transformed the ride.

Andyb

Back to Top
asaleo View Drop Down
Falcone
Falcone


Joined: 09 Sep 2016
Location: Västerås
Status: Offline
Points: 72
Post Options Post Options   Thanks (1) Thanks(1)   Quote asaleo Quote  Post ReplyReply Direct Link To This Post Posted: 03 Nov 2018 at 19:40
If oil has been overfilled and resulted in a lot of oil in the air box, oil may have been drawn into the throttle housing. Oil may then seal small openings in the throttle housing. This case is something I have read about earlier somewhere. I don´t remember how they managed to clean the housing. Check the inside of your air box to see if there is a lot of oil in it. If there is a lot of oil in it you may have got it into the housing.
Back to Top
Brian UK View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Surrey
Status: Offline
Points: 9422
Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 03 Nov 2018 at 21:18
It has come up before. Trouble is, I can't remember what the problem was. Saw a video of it happening.

If the throttle return cable had become disconnected, you could have this happen.

But as suggested above try removing that fuse, or even disconnect the battery for a minute or so.
Brian.

Better 5 minutes late in this world than years early in the next.
Back to Top
asaleo View Drop Down
Falcone
Falcone


Joined: 09 Sep 2016
Location: Västerås
Status: Offline
Points: 72
Post Options Post Options   Thanks (0) Thanks(0)   Quote asaleo Quote  Post ReplyReply Direct Link To This Post Posted: 04 Nov 2018 at 06:45
I found the notes about what happened after overfilling oil in engine. The result was a lot of oil in the air box which also was drawn into the throttle body.
When oil filled small channels in throttle body, bike could not keep a steady rev. 

"The issue is that the engine seems unable to maintain a constant rev level. Whilst standing and idling the revs fluctuate between almost 1000 to up to about 3-4000. It'll sink lower and lower, almost stalling, then rev furiously up to 3-4000 or so, before settling back in the middle for a bit, then falling again." 

Notes from workshop:
"They confirmed that as Mark Bayley suggested, oil had gotten into the various channels and sensor bits in the throttle body. They replaced a couple of sensors and confirmed all the oil was cleaned out. I've ridden the bike for a week now, and so far no issues. Looks like it is completely fixed. It runs great again, and is again a pleasure to ride!"

Your problem may be other things but I think it is good to know what can happen with to much oil.
Back to Top
Brian UK View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 13 May 2014
Location: Surrey
Status: Offline
Points: 9422
Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 04 Nov 2018 at 07:43
Wonder which sensors they replaced.

But this could have been the underlying issue in the other cases, where the throttle body was just replaced under warranty.

I do know from experience that overfilling the engine oil will result in lots of oil in the air box. Happened on my Norge too.


Edited by Brian UK - 04 Nov 2018 at 07:47
Brian.

Better 5 minutes late in this world than years early in the next.
Back to Top
Andyb View Drop Down
Senior Member
Senior Member
Avatar

Joined: 02 Jul 2016
Location: Nottinghamshire
Status: Offline
Points: 159
Post Options Post Options   Thanks (0) Thanks(0)   Quote Andyb Quote  Post ReplyReply Direct Link To This Post Posted: 04 Nov 2018 at 16:20
I am not saying that oil in the airbox would not cause this problem, but I am pretty sure the oil level was OK on my bike without more than oil dampness in the air box.....and the new TB sorted the problem and has not failed again.  Quickly touching wood.
Andyb
Back to Top
jefrs View Drop Down
Senior Member
Senior Member
Avatar

Joined: 12 Aug 2018
Location: West Berkshire
Status: Offline
Points: 278
Post Options Post Options   Thanks (0) Thanks(0)   Quote jefrs Quote  Post ReplyReply Direct Link To This Post Posted: 04 Nov 2018 at 18:05
If the breather filter has become saturated with oil then the motor, which is effectively a high volume vacuum pump, will suck oil out of its sump through the breather pipe, and you will find oil in the air box. 

Remove the caps from the breather box to drain oil out. Mop out the air box. Disconnect the breather pipe and put it on e.g. a little K&N breather filter.  Carb and injector cleaner spray may clean the throttle body without dismantling; not tried on the V7 II but have on other motors.

One of the breather pipes from the cylinder heads may be split which encourages oil to be brought into the breather filter. 

I've got oil in the V7 II air box but the motor is not racing. There is an issue with lumpy slow running which the dealer reckons is a faulty left HT Lead and split breather pipe. I'm going to let the dealer have a go under warranty before I tell them how to fix it or do it myself.



Edited by jefrs - 04 Nov 2018 at 18:08
Back to Top
Andyb View Drop Down
Senior Member
Senior Member
Avatar

Joined: 02 Jul 2016
Location: Nottinghamshire
Status: Offline
Points: 159
Post Options Post Options   Thanks (0) Thanks(0)   Quote Andyb Quote  Post ReplyReply Direct Link To This Post Posted: 04 Nov 2018 at 19:28
Jefrs - Lumpy slow running - remove the lambdas!  You can disconnect them at the electric plugs yourself very easily and it sorts this problem out - removing them and plugging the hole in the exhaust is the long term solution.

Going back to whether a TB can be impregnated with oil....an indication would be if the air filter is contamineted with oil.  Mine was not.

Agree that if the air filter is blocked then the engine will suck air from wherever it can....perhaps a KN filter with less resistance than a paper filter will help to stop oil entering the air filter box?

AndyB



Edited by Andyb - 04 Nov 2018 at 19:31
Back to Top
deltic View Drop Down
Falcone
Falcone
Avatar

Joined: 07 Oct 2014
Location: surrey
Status: Offline
Points: 83
Post Options Post Options   Thanks (0) Thanks(0)   Quote deltic Quote  Post ReplyReply Direct Link To This Post Posted: 05 Nov 2018 at 11:32
my 2013 v7 racer did the same thing once dealer had to reset ecu
Back to Top
asaleo View Drop Down
Falcone
Falcone


Joined: 09 Sep 2016
Location: Västerås
Status: Offline
Points: 72
Post Options Post Options   Thanks (0) Thanks(0)   Quote asaleo Quote  Post ReplyReply Direct Link To This Post Posted: 06 Nov 2018 at 12:35
There are anti return valves in both hoses from upper frame pipe. Thus it should not be possible for a blocked air intake to get oil from sump or push air into valve head covers.

Edited by asaleo - 06 Nov 2018 at 12:39
Back to Top
 Post Reply Post Reply Page  12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.00
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.063 seconds.