Sudden engine shutdown

[Guest John Sears]

The main issue I seem to be having with my V11 Sport (besides being totally addicted to it) is the engine cutting out completely just as I am about to stop - not every time, but usually after a good hard blast. It will be running great, no problems, and then, if I come to a stop sign or light, or sometimes if I'm just slowing way down to make a sharp turn at an intersection, the engine just stops. No missing, coughing, etc - just cuts out, right at the point where it transitions from the higher revs of running, then downshifting, rolling off the throttle as I'm stopping, - right where it enters the idle range - it just stops, like it can't make that transition from running to sudden idle. When the bike is just sitting there, it idles perfectly, and handles going from high revs to sudden idle with no problem, which makes me wonder if there's something related to deceleration involved (fuel surge/slosh?)

 

It first started this past Summer, on hot days, and I thought it was a heat-related thing, but it still happens now, even on very cool days, although less often.

 

Moto Int'l says they think it may be loaded up with gas while at speed and is then not able to get rid of it quickly enough when I suddenly roll off to idle, so it chokes on that too-rich mixture and dies.

 

I (and they) have tried adjusting the fuel map with the PCIII, both adding fuel to richen it at the very low revs in order to give it a boost at idle, and we've tried the opposite, leaning it out so much at the bottom of the rpm range it starts idling rough and almost won't keep running. That actually seemed to help the most, but it still hasn't fixed it.

 

Anybody else seeing this? Any ideas?

 

Thanks very much!

 

John S.

'01 V11S, approx 5000 mi.

[callison]

My V11TT does the same thing, more so now that it has a few miles on it (>7000). My Sport 1100i does it to the extreme that I've parked the bike as it is now too dangerous to ride. It either dies, or remains at 3000 RPM for awhile before returning to idle... then dies. I'm hoping a PCIII will fix the problem, but if that fails, I'm looking into a replacement ECU from a guy in Australia.

[dlaing]

Interesting problem. My immediate thought was that it was too rich at the closed throttle position. And you did say that leaning it out at lower rpms helped a little. I would try leaning it out at the lower throttle positions rather than the lower rpms. I would also try taking the PCIII off the bike to see if that helps. Unlikely culprit, but easy to try. Next guess is a bad TPS??? Bad coils getting overheated then lacking voltage at idle???? Too tight of valves????? I imagine you have tried new spark plugs.

[Frank]

John

 

My '02 V11 Lemans did the same thing from new. My dealer fixed the problem and it doesn't cut out any more. He adjusted the valves to .004 inches exhaust and .006 inches intake, balanced the throttle bodies and readjusted the TPS, removed the tip over valve and probably rechecked the CO emissions and enrichened them somewhat. Been perfect ever since.

 

Frank

[Guest gavin]

Although I did not consider it a major problem at the time as it has only happened a handfull of times (am I getting to used to 'character'???) my V11 Sport used to cut out as described - after I completed the last routine service of oil, filter, plugs, carb balance (they where a long way out) it has not done it again - that was 2000 miles back.

I can't imagine that the service cured it so I would be interested in other theorys as well.

[Mike Stewart]

Hi John,

 

Welcome to the V11S addiction page

 

I have been fighting the dying issue since I have owned the bike. It seems to do it only when the days are hot and only when doing a full throttle blast and coming to a stop.

 

The most important thing to adjust is your idle speed. It is very critical that it is set on the high side (1200 rpm). It is best not to use the Guzzi tach. Mine reads 300 rpm high, so 1200 rpm will come out to be about 900 rpm. and it most certainly will stall.

 

I have checked everything from TPS voltages to CO. mixture reading and I have had no cure. The PCIII was no help for this condition either.

 

I have also played with valve lash specs. and using Raceco's larger valve clearance specs. does seem to take away the hot blast stall syndrome. So I suggest opening up your valve lash and adjusting your idle speed (hot) and go for a ride.

(By opening up the valve lash a few things change. The valve overlap is reduced and the valve opening is also slightly reduced. This will give your bike a very smooth idle and improved low end with just a little loss of top end).

 

 

[Guest John Sears]

Hmm, lots of good tips, everyone - Thank you all! You hit on several things I've wanted to try, to address the hot-weather issues (valve adjust, idle speed) but hadn't gotten to before the hot weather ended. But since I'm still having trouble with the stalling, I'll still try those things out. I've wondered how accurate the tach is, and the speedo, for that matter. As for the PCIII, it was stalling before I added it, so although it helps the symptoms somewhat, it didn't cause them. I will try focusing on the lower throttle positions, and maybe combine that with Mike's suggestion about increasing the idle speed.

 

So, I've got some good things to try. I'll let you all know what happens. (And still welcome any other suggestions!)

 

Thanks again,

 

John

[Guest IanJ]

This sounds a lot like the problem I'm having now, where my Le Mans will cut out for a second while riding along -- I've had the same thing happen (see "popping and misfiring") at idle, which can kill the engine. Micha at Moto International suggested that it might also be a problem with the pulse sensor, which tells the computer where the crankshaft is in its revolution. MI is about to take my bike for a little while to try and track down my problem, and I bet that (if they figure it out) the solution could be applied to your bike with similar success.

 

Lots of people (including MGNA's tech, Terry) have mentioned that this engine has to have things set up just right, as far as throttle body sync, TPS, etc. before it will run properly.

[jtucker]

TPS, fuel mixture, and sync seem to have *alot* to do with this problem. Whenever I take it into my mechanic to let him work his magic, the problem is completely eliminated. Unfortunately, it always comes back some time later. :-(

 

__Jason

00 M900Dark

00 V11 Sport

[Guest gavin]

I have also played with valve lash specs. and using Raceco's larger valve clearance specs.

 

 

Sounds like a good tip - if possible please supply details. I have the 'Raceco' chip fitted but am unaware of any valve change. What is the affect on valve noise?

 

Thanks

 

Gavin

[Mike Stewart]

Hello all,

 

This is from Raceco's web page:

 

Tappet clearances for two and four valve engines:

 

Two valve engines

 

Tappet clearances for the Guzzi big twins should be set to 0.20mm for the inlet and 0.25mm for the exhaust. This also applies to the "modern" Guzzis such as the Sport 1100, Cali 1100i and V11. The factory settings for these bikes are 0.10mm and 0.15mm respectively, but this is to try and reduce engine noise to meet US emissions regulations. With tappets set this tight, the engines have trouble ticking over and running cleanly at low revs.

 

Give it a try, it does not cost anything and it may solve your problems,

 

Mike Stewart

[Guest Jbeaglepoint]

I agree 100% with Mike's post about the valve adjustment being too tight. I had the exact same problem and it was cured by loosing the valves to Raceco specs. Adding a powercommander did not fix the problem.

[Guest Squashed Nose]

I have two 'cutting out' related problems. Several times, during hot periods (very rare in Britain) I have pulled up at a junction, the engine has slowed and stopped. Nothing dramatic, started ok afterwards. I have also experienced this when I got caught in an horrific traffic jam in Bordeaux earlier this year (also in hot weather). I put it down to an overheating problem and thought it was something I was just going to have to live with on an air cooled bike.

 

The other problem is that, occasionally, the bike will 'cough' and miss. Not a problem if riding in a straight line but it happened once when I was circumnavigating a roundabout and, of course, the bike just flopped over. If my reactions had been slower, the bike would have ended up on the deck. I put this down to an occasional fuelling glitch and another MG idiosynchracy.

 

Surely it is these little foibles which make us love these bikes so.

[Guest hyper]

My rosso had the problem of stalling when I slowed down quickly after a hard run. It would also want to stall when warming up. The dealer was useless and said it's running properly. I set up the tps, valve lash at 4+6 thou. Synched the throttle bodies but it still wasn't right. My next step was to adjust the air bypass screws, I found that they were screwed all the way in, I went for a ride and screwed them out until the stalling stopped. For my bike that was 2turns out. The bike now idles and warms up properly and doesn't stall. There are no flat spots in the power band and the spark plugs are a tan color. Fuel mileage is 50 mpg canadian at 70 to 80 mph. Me very happy.