Vapour Lock??

[Gini Fata]

The last two days after a good ride and about an hour later when I went to leave, the bike fires up no problem but has no power like i am out of gas. It stalls, but fires up again ok and off I am to the races. I have read all the posts on the vapour problem but in most of those cases the bike does not fire so I am wondering about what it could be. The bike is in fine tune and runs great. I have the electric petcock on it and will change it once my oil is due for a change so I put installl the roper plate as well. Any ideas????

[badmotogoozer]

I was a vapor lock sufferer...

 

It does sound like vapour lock except that after 1hr it should have cooled sufficiently to return to liquid. With mine it always occured ~15-20 mins after I shut it down and was just fine 30 min later.

 

Does it stall and then immediately fire? If so then I would doubt vapor lock... Usually you would have to wait a while before it would go again.

 

I'm sure there will be other thoughts...

 

cheers,

 

Rj

[Steve G.]

I was a vapor lock sufferer...

 

It does sound like vapour lock except that after 1hr it should have cooled sufficiently to return to liquid. With mine it always occured ~15-20 mins after I shut it down and was just fine 30 min later.

 

Does it stall and then immediately fire? If so then I would doubt vapor lock... Usually you would have to wait a while before it would go again.

 

I'm sure there will be other thoughts...

 

cheers,

 

Rj

 

Ryan is correct. If you are impatient like me, you can "burp" the vapourized fuel off the left side hose, disconnecting it, it will come out as air.

I found the main cause of this on my bike was due to bad fuel line routing, which had the main fuel line comfortably nestled against the back of the left cylinder, superheating the bloody fuel. Since I have re-routed the lines away from the engine, the problem has stopped, in spite of riding/stopping in 100 degF heat.

More than any other make of motorcycle, my Moto Guzzi has made me into a self imposed engineer of common sense, and I am able to diagnose and see evidence of 'lazy' engineering with mechanical machinesbetter than before ownership. And for that, I thank Moto Guzzi's engineers.

 

Ciao, Steve