2002 V11 Backfires/Won't Idle

[Tommy Molotov]

Hi all, new to the forum here. I have a 2002 V11 Le Mans that has until recently run fairly well.

 

Now, it hesitates to start and needs a little throttle to do so. Half the time it'll backfire when it does start.

 

After that, it stalls if I let go of the throttle. It won't idle, even after I let it run for a little while.

 

At first I thought it was the right side fuel line. It had cracked and was actually leaking fuel. I figured that cylinder was just being starved and thus causing those problems. But now that that's been replaced and it isn't leaking anymore, nothing has changed.

 

Any ideas? I'm not very experienced but won't be able to get it to a mechanic. Hoping it's something simple.

[Tom M]

Hi Tommy,

Welcome to the forum. I'd start with checking the rubber intake boots for cracks. Also make sure the throttle bodies are seated in them correctly and their clamps are snug.

 

FYI the fuel line on the right side of the tank is the return line for the fuel injection. It doesn't supply gas to the right cylinder.

[Tommy Molotov]

Hi Tommy,

Welcome to the forum. I'd start with checking the rubber intake boots for cracks. Also make sure the throttle bodies are seated in them correctly and their clamps are snug.

 

FYI the fuel line on the right side of the tank is the return line for the fuel injection. It doesn't supply gas to the right cylinder.

 

That's probably it...they're both cracked pretty good now that I look at them. Everything's snug but the rubber is practically shredded in places, on those boots. I'll replace those and see how it works.

 

Thanks!

[fotoguzzi]

those rubber boots are pretty thick... when is the last time the valves were checked-adjusted?

[docc]

Valve adjustment , spark plugs, and a throttle body balance will make her feel like your best girl with a new diamond bracelet and a night on the town.

 

But for under fifteen bucks!

[Tommy Molotov]

So far I have: adjusted the valves to 0.10mm intake/0.15mm exhaust, cleaned and adjusted the gap on the plugs, and checked over the TB boots to make sure there isn't an air leak there.

 

The left intake valve was way, way off, so we figured that might have been the cause of the problem.

 

Afterward, the idle was a bit better but still sort of low. On the verge of stalling. So we then adjusted the idle, with the screw on the left throttle body, to about 1000 rpm.

 

Now it idles fine...

 

...but taking it out on the road, the bike is now incredibly sluggish. It'll get up to speed but seriously lacks power compared to before.

 

I have yet to balance the throttle bodies, so I'm wondering if that's what's missing, or if I messed up on one of the other steps. We triple checked the measurements though.

[The Monkey]

Desite the fact Guzzi recommends 0.10mm and 0.15mm int/exh. for valve clearances, the bikes are much happier at 0.15/0.20mm int/exh. Synchronize your throttle bodies. ensure the tank insulation hasnt fallen onto your intake (if running open air box)