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T5 1983 850cc

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Surfrider Barry View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Surfrider Barry Quote  Post ReplyReply Direct Link To This Post Posted: 15 Jan 2018 at 20:32
I've done all the cleaning of the ignition terminals and triggers ,oil change and cleaned and checked sump now waiting for braided brake hoses before giving it a run to see if it's firing good on both cylinders. Now I have been checking out carbi choices and the TM Mikuni 38mm flat slide non accelerated pump carbi is recommended, has anyone fitted these and had good results? I'm also looking at fitting Lafraconi mufflers which should help the breathing.
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Mike H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 16 Jan 2018 at 00:33
Try not to do too many things at once, or you could get in a right muddle. Fix the misfire first. The other stuff could make the situation worse or add more problems but you won't know which extra thing you did caused it.

Originally posted by Surfrider Barry Surfrider Barry wrote:

I put new plugs and leads in today and it runs better but still when I take the left plug cap off it stalls but when I take the right lead off it slows but doesn't stall

If memory serves Haynes manual says take one cap off, should idle a few seconds then stop, ditto other side, then idle settings for carburettors is correct.

Having said that however you MUST NOT disconnect a spark plug with the engine running if it has electronic ignition.

Quote and theirs a lot of back pressure when I removed the dipstick at idle.

Never heard of doing this before and can't think why one would want to.


Originally posted by Brian UK Brian UK wrote:

I thought they had gone to Nikasil by 1983.
 
The exhaust cross piece does help mid range and getting the balance between the pots right.

Main function of a crosspipe is to tune the downpipes to a specific length, this causes negative pressure pulses to go back up the pipe to the head and scavenge some more exhaust gas out, at a specific rpm, so removing the crosspipe may very well cause a reduction in engine output at that rpm. Some designs have two crosspipes (e.g., Le Mans) so exhaust scavenging occurs at two different points on the rpm range. Somewhere I have a book (or did have) that explains it all.


HTH

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Surfrider Barry View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Surfrider Barry Quote  Post ReplyReply Direct Link To This Post Posted: 16 Jan 2018 at 23:03
I have changed the oil in the final drive and found the level plug thread just about striped and wonder if there is a way of helli coiling a new thread without stripping the drive to pieces. Anyone else have this problem?
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Mike H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 16 Jan 2018 at 23:42
Yes and it was recomended that it has an insert, as the casing wall is not thick enough to take a helicoil. You need a freindly neighbourhood engineering works.

They did do it without it having to be stripped to the bare casing, but it needed thoroughly flushing out afterwards to get rid of any swarf.

On mine both level & drain holes needed doing.


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Ken-Guzzibear View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 17 Jan 2018 at 21:48
850 T5 works well on the round phf 30 carbs best thing about T5 engine is the 1000cc cylinders/ pistons fit straight on the only square cyl engine that is compatible according to Guzziology .....the 850 T5 engine is as powerful and better top speed than the standard V1000 engine in the G5/Convert/Spada apparently fit the round carbs with triangular pump at the top back edge they work real well .....
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Surfrider Barry View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Surfrider Barry Quote  Post ReplyReply Direct Link To This Post Posted: 17 Jan 2018 at 22:33
I thank Ken for your advice but im being recommended by Mikuni Australia to use the TM 38mm flat slide without accelerator pump and expressed concern about being to big when the Moza has 36mm carbis and they said the big Ducatis all fitted these 38s in the 80s with good results and they also said the 34mm carbis would do the job to so what are the experienced good people on the forums thoughts?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 17 Jan 2018 at 22:47
What's the inlet port diameter?
Brian.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Surfrider Barry Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jan 2018 at 09:53
I'll take the carbis off tomorrow and measure Brian and strip them down and give a good clean and blow air through their canals. Did run it today with coils reversed but no change it seems to not fire cleanly on the right side but not the left until about 3 to 4K revs then smooths out nicely I'll post results tomorrow after I clean the carbis
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken-Guzzibear Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jan 2018 at 11:13
T5 are 30mm carb standard I think you can fit the cali type 36 ....there will be back pressure in the sump with the plug out which is why there is either a ball valve breather atop the sump OR a Le mans breather with flapper valve..nb the ball valve works best ...loads of info on the Aussie AIGOR site .....Never seen Mikhunis on a guzzi in the UK seen one with the BMW type carbs on it
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cyclobutch Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jan 2018 at 13:11
Bing
Butch
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T3 - 'Blue'
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike H Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jan 2018 at 13:51
Large dia. carbs will give poor slow speed running and worst fuel economy, 30mm works very smoothly for small throttle openings, which to be honest is most of the time, and better mile per gallon, when I changed from 36mm DellOrto to 30mm I got an extra 10 mpg. From low mid 40's, to high 40's even 50.

HTH

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jan 2018 at 14:25
But pumper carbs are the ones to avoid if fuel consumption matters.
I disabled the pumps in the 36mm Dellortos on the SPIII, and fuel consumption went up to the mid 60s mpg. Precious little difference on acceleration too. (Well that's what a friend on his Centauro said when he followed me).
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