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V35 imola will not start

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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: 29 Jan 2019 at 17:28
Originally posted by Thetar Thetar wrote:

Definitely points.
"Chicken nuggets don't dance on a Tuesday."
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GuzziTim Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jan 2019 at 19:15
is the air filtration system in place? 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thetar Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jul 2019 at 21:16
so after taking a few months away from the guzzi for therapy I spent a few evenings trying to figure it out.  Checked Atiming and points and they were ok.  New battery and filled the tank (8 inches extra head pressure). Hey presto it runs. Pick up from idle is bad. Unless I set the idle to 1800 then it will stall when I open throttle. Any ideas what could improve idle response?

Will try and take it out for a ride tomorrow, maybe it just needs a good blast. 


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Post Options Post Options   Thanks (0) Thanks(0)   Quote AdrianW Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jul 2019 at 22:04
Glad you are making progress..  I have only just seen this thread as I joined the Forum only recently but can sympathise with your issues..

I have a 1982 V35II which is still a right b*st*rd to get running smoothly..  It is interesting to read all of the comments so far as I am having one hell of a job getting mine to run properly also. It runs rich whatever you do.
Personally I'm not impressed with the smaller dellortos (PHF's are fine).  I would NOT recommend looking for VHB's unless you know them to be excellent, that (26mm) is what is on mine..

I have tried lots of fiddling and new manual chokes so far with little change, mostly made things worse.  My bike starts and idles fine, pickup and general running is rubbish.
try:
Set the idle mixture screws 1 1/2 turns out
Make sure your slides are both bottoming together and that there is free play at the throttle end on both cables. I checked the bottoming by unscrewing the throttle stop screws completely.

I then tried screwing the stop screws in comletely and then unscrewing them by an equal number of turns on both sides. This did not work !  Todays' final effort was to try the reverse approach - work out roughly where the throttle stop screw starts to work and then screw in by an equal number of turns..
It seemed slightly better but it was tea time and two other bikes were now in the way so I didn't get it out on the road again..

Mine isn't as pretty as yours :-


Good luck... I'll keep you posted with any progress I make..  I am going to look at float levels and needle position next ...

Adrian
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Post Options Post Options   Thanks (0) Thanks(0)   Quote c13pep Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2019 at 09:28
The phbh28 carbs do need to be spot on for bike to run properly ie. all jets clean and in good condition (renewing needle and atomiser jet is usually the least you can get away with after the chokes). Float levels also have to be accurately set as does balancing the carbs once the bike is managing to tickover and rev to 3000 RPM.
Just as a follow up to my earlier point about engine size the later Imola crankcases will accept V50/3 barrels, only way to easily check would be to remove one head and measure bore diameter.
you can`t have any fun in a straight line

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Thetar View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thetar Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2019 at 14:39
yours looks great Adrian. Mine is a bit of a Frankenstein with bad paintwork. Anyhow, I took her for a proper run and she died on me. Started again after cooling off a bit. But would not pick up past idle. Just died with the extra throttle. 

During the ride, hard to revup up enough to get moving at traffic lights. Left side is reluctant to fire, and backfires somewhat. Walked her home and checked plugs. plugs on right were fouled. Left were ok. Right side carb overflowing, this is fixed by tapping the bowl. Mixture screws seem to have no effect. Oh, and, I think I'm using bigger than normal carbs from a v50 - I raised the big needles to 4th position to richen and compensate.

I have no idea what's going on. Probably a number of things...  I  suspect timing  on left is out, floats on right are too high. Carbs not balanced? Valve clearances? Well at least it's running and I have some data to  work with. Nearest Italian bike workshop - 4miles! 


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Post Options Post Options   Thanks (0) Thanks(0)   Quote AdrianW Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2019 at 17:55
Hi Thetar,
At least you got it going..   The roundslides are better than the square VHB ones. Yours are from a V50III I suspect but 2mm isn't a lot...
If you feel inclined I would look at both carbs. The RHS sounds like the float needle is sticking causing overflowing. Usually it's just a bit of crud getting in the way of the float needle housing but simulates  the choke being on all the time. I'm not sure I would have raised the needles that much, the jets are almost certainly larger than those on a V35 carb already so you are effectively adding more fuel to the equasion. I appreciate that more air is going in but at low to medium throttle openings I would not have thought it would need more fuel..

Backfiring can be either ignition problems or intermittent flooding causing fuel to collect in the silencers. You could try swapping plugs over - if yours are NGK it would not be the first time that new ones have proved faulty. Also some plugs fail pretty quickly if subjected to erratic running or excessive fuel..  I must get a spare set for my bike..

Advice here has been to balance carbs which I must attempt to do. May help yours also..

You are lucky to have an Italian specialist that close, I do not!! Mind you if they are good their bills tend to be large to match their expertise...

I have not had chance to even look at mine today, summerhouse needs repairing and management has dictated that that has priority....
Good luck with yours, I'll keep you posted with what I try on mine !!
Cheers,

Adrian
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jul 2019 at 21:29
Oversized carbs won't help at all.
Brian.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thetar Quote  Post ReplyReply Direct Link To This Post Posted: 16 Jul 2019 at 23:28
oversized carbs won't help but don't explain the behaviour. Here's what I'm going to do: lower right floats, retard left spark. That almost sounds like I know what I'm doing.

Adrian, if you want keep your job, do what management says. 
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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 Jul 2019 at 07:29
No, you make sure both floats are at the correct level, don't just change things out of spec. Same goes for ignition timing.

Fitting oversize carbs will change all the jetting, and you have no idea what should be correct as there is no reference available. No point in jetting according to a manual as that would assume the correct choke size.
Oversize carbs will always make an engine more intractable.

What carbs are actually fitted?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AdrianW Quote  Post ReplyReply Direct Link To This Post Posted: 17 Jul 2019 at 15:18
Thetar,
Have to agree with Brian here.. Ignition problems often look like carb ones and vice versa..

Check the float level certainly, likewise the timing, but I wouldn't alter either from spec...

If you have V50 carbs according to my manual they should be PHBH 28s, marked BD (right) & BS (left). Throttle valve should be 50, Atomiser 268T, main jet 118, idling jet 50, starter jet 60. Needle X6 on third notch.(not sure if measured from top or bottom!).
Idle adjuster screw (like the V35 and V65) 1 1/2 turns.
Float height (doesn't say which carb!) 23.5 - 24.5mm.
The V35 carbs are different entirely apart from the starter jet which is the same size..

I would have both plugs out and on the starter see if there is an obvious difference in spark colour, frequency  & intensity before altering timing..

Hope this helps.. I'm still on "management" tasks but as you say there are times when it is best to obey... !!

Cheers,

Adrian
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ben. Quote  Post ReplyReply Direct Link To This Post Posted: 17 Jul 2019 at 15:48
You mentioned that the right carb was overflowing and stopped when tapped.
That sounds more like a sticking fuel valve than a wrong float height.
The first would give intermittent trouble, the second would be a steady state.
Both can co-exist.
With carb problems it can be a good idea to begin at the beginning -- the tank.
When you're sure that's clean, not rusty, and inline filters are in place, and fuel lines are in good condition and not disintegrating inside, then the carbs stand every chance of responding properly to adjustment.
... and here's hoping they do.
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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 Jul 2019 at 16:52
The V35 II should have 26mm carbs.

The V50 III would have 28mm carbs.

But the earlier V50 II would have 24mm VHBs, same as the V35.

If you have the 28mm carbs on the V35 II, then unless severe porting work has been done there will be a step in the inlet tract, this will cause all sorts of problems.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thetar Quote  Post ReplyReply Direct Link To This Post Posted: 17 Aug 2019 at 20:40
Update. I've had no success. Checked timing and pointb etc. All good. I put in a new lighter float on the right carb and that fixed the overflow. 

But still runs crazy. Right spark gets fouled quickly. It will idle ok, but stalls if I apply throttle. If I apply throttle real slow I can build up revs but lots of loud popping. Revs eventually drop down as right plug gets fouled, within 10mins.

Suspect you are all correct. I need to get the correct carbs. Current ones are off a v50 (28). They're expensive though. Was hoping I could make it work with 28s, but maybe not.


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AdrianW View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AdrianW Quote  Post ReplyReply Direct Link To This Post Posted: 18 Aug 2019 at 08:48
If it's any consolation I can't get my V35II to run properly either , even with the correct carbs.
New ones are exhorbitant and in rocking horse **** territory.. 
Thought of VM26 Mikunis to replace them but they are just as bad plus an unknown quantity..

I'm going to put the needles as low as I can get them and then start replacing bits I guess.. (I've already fitted new manual choke levers).

Good luck with yours, I'll keep you posted with mine...

Cheers,
Adrian
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