It stalls

[Guest turtle]

My 2004 lemans has a tad over 1000 mi on it. I love this bike .

Sadly, it has recently caught a bug . It idles at about 1000rpm but periodically hiccups and stalls while sitting at a light. I live in Maryland and spend most of my time going to work at lights . Any help would be greatly appreciated.

 

Thanks so much.

[Cliff]

Thats not too unusual.

 

Things to check are throttle synchronisation.

Throttle position sensor adjustment.

 

A simple thing is increase the idle speed. I think you'll find the manual recommonds 1100-1200RPM. I've heard idling too low can cause unnecessary wear around the clutch. The sports have fairly low flywheel weight and hence don't like to be too slow.

[bento]

yah, 1100-1200. it keep running then.

[al_roethlisberger]

Check the valve lash.

 

This is the exact problem I had for MONTHS last year, that my dealer couldn't solve, after they had had the heads off. Once the bike was good and heated up, it just wouldn't idle. It would cough, spit, lope, and die.... after a highway run, at redlights, in traffic. It was unrideable <_>

 

So after some thought, my "common sense" kicked-in-gear and I thought, "gee, what would heat do to make the engine not want to idle that wasn't fuel related" and surmised that the valve train was taking up all of it's lash when heated, and was binding up, not letting the bike idle.

 

The dealer didn't listen to me though, and after weeks of their own tinkering, they finally just gave it back to me and said, "...just go ride it a bunch and it will loosen up"

 

 

Anyway, long story short, Mike Stewart came over and we set the valve lash to Raceco specs, and it's never had an idle hiccup again.

 

Check the valve lash

 

al

[Guest Brian Robson]

I agree with Al. 0.15mm intake and 0.20mm exhaust...and that is what is printed on the sticker on the swinging arm underneath the hugger, which is interesting given all of the different quoted measurements.

[Guest rotorhead]

I experienced the same problem some time ago and indeed opened up the valves as mentioned and synch the TB's and adjust the idle up slightly.....runs quite well. That and mileage accumulation and things should improve.

[twhitaker]

I was told by a mechanic that if the mirrors are vibrating the idle is too low. Low idle also equals low oil pressure. Bumped it up to 1100 rpm and the vibration went away. I put on a K&N air filter and the idle bumped up to 1200 rpm so I bumped the idle back down.

[Guest Jeff Kelland]

Oh yeah, opening up the valve lash is a must, stalling goes away, runs smoother, and after 9500 miles, no downside! I kept mine a bit tighter than raceco specs, .006 intake and .008 exhaust.

[Guest Warren Rhen]

A simple thing is increase the idle speed. I think you'll find the manual recommonds 1100-1200RPM.

Can you adjust the idle speed without screwing up the sync of the throttle bodies. If so where do you adjust it at?

[docc]

'Jeff in Ohio' has given us a really nice 'How To' on idle/TPS and throttle body synch. There is no real substitute for doing the whole she'bang.

 

That said you can back your air screws out a little to tweak the idle . Or screw in the idle slop screw on the left throttle body.

 

Again, best results are achieved by valve adjustment and carefully setting the TPS, throttle body synch and quaffing grappa.

[docc]

Here is the current take on the "Decent Tune-up" using the tools we have available today for ECU interface and TPS setting:

https://www.v11lemans.com/forums/index.php?showtopic=19610