bike dies when throttle closes

[beckman48]

2002 V11 LeMans which I have owned for a year. 9200 miles.

 

On two occasions, after the bike has been running for about an hour at highway speeds it has quit running. On both occasions, I was approaching a stop, pulled the clutch and was starting to downshift through the gears as I coasted toward the stop sign. I had let off the throttle and instead of going to idle, the engine just quit running.

 

First time about 6 months ago. Again today. The weather was clear with moderate temperatures.

 

On both occasions, as soon as I pushed the starter switch the engine fired and ran smoothly. No problems during the rest of the ride. Nor had the engine performed poorly previous to the event.

 

Bike has factory titanium mufflers and the associated ECU. Relays were upgraded.

 

What would you check?

[Tom M]

I've had that problem in the past and I fixed it by adjusting the valve lash (.006" intake/.008" exhaust) then syncing the throttle bodies then setting the idle and the the TPS. That said I think the "flame out" that you experienced is probably due to the valve lash tightening up when hot possibly combined with a low idle.

 

Check you valve lash, adjust it if needed then set your idle to 1050rpm and see if that helps.

[docc]

That's good advice!

 

Do a full "tune-up" and realize the Tachometer may not read true. My (early) white face Veglia is 300 RPM high. That means I have to set all parameters at tune-up to an idle indicated on the tach at 1350. Frankly, I shoot for 1500 (indicated) as more is better for oil pressure and idle stability.

[guzzimeister]

Hi

 

when it happened to me, it was an air leak at the injector to head rubbers plus a TPS setting on the low side. Both are easy to check and described in detail in this forum. To check for leaks, sometimes sqirting WD40 around the suspect area detects a leak by the engine increasing revs when idle. Also check the rubber retaining clips. The rubbers (especially left side) are a B$st$£r to locate properly yet seem to have no problem working loose.

 

All the above comments re idle speed are relevant but I would say get the injectors balanced with a correct TPS setting and the bike will idle all day at an indicated 800rpm quite smoothly. Don't like fast idles because the bike overheats and loses oil pressure in heavy traffic like all Guzi V twins since Genesis.

 

I will now be controversial and say that while setting vlave clearnces, new relays, and balancing the injector bodies undoubtedly helps, most of the problems with poor running on this forum are either air leaks or TPS settins, ie lean running. Despite having an ECU and injectors the injection system on V11s is very crude, especially ythe pre lambda sensor types. Treat them like carbs except that the TPS adjust both idle and main jet settings, if you see what I mean, and you can diagnose faults very quickly.

 

The weird bits about the system are when sensors malfunction, or relays make poor contact or fail. The former usually makes the ECU default to a rich get you home setting and is pretty rare. This is tricky to diagnose cheaply. The latter usually lead to fuel starvation symptoms, ie misfiring or cutting out dead at speed, which is not surprising because fuel supply is afected by these parts.

 

Cheers

 

Guzz

[luhbo]

 

... First time about 6 months ago. Again today. ...

 

Twice in a year? You really want to spend a day of your weekends to make a full tune-up adjustment session? How about just pressing the starter button (just in case it happens again next spring) and before that shift down while you approach the lights, gear for gear?

 

Hubert

[Mike Stewart]

Being that it only has happened twice, start with the valve adjustment and throttle sync. I was the first one years ago to come up with the fix with running larger valve clearences to rid of the stalling when coming to a stop at freeway speeds. My 2000 V11 sport would not run right with the stock valve clearence specs. I have also fixed other V11's by readjusting the valve lash after they had been to the dealer.

 

Mike

[V11CSGoozer]

Being that it only has happened twice, start with the valve adjustment and throttle sync. I was the first one years ago to come up with the fix with running larger valve clearences to rid of the stalling when coming to a stop at freeway speeds. My 2000 V11 sport would not run right with the stock valve clearence specs. I have also fixed other V11's by readjusting the valve lash after they had been to the dealer.

 

Mike

Mike, I'm having these same issues with rough, low idle, stalling and cutting out at higher revs, around 6k. What valve clearance do you suggest to run on an '04 Cafe Sport? Thanks.

[fotoguzzi]

I've had that problem in the past and I fixed it by adjusting the valve lash (.006" intake/.008" exhaust)

[V11CSGoozer]

I've had that problem in the past and I fixed it by adjusting the valve lash (.006" intake/.008" exhaust)

D'oh!!! Thanks for straightening that out for me. ; )