XS750 carburetor vaporlock

77XS7502D · 05-23-2012, 12:46 PM

title says it all, but whats convenient my repair manual doesnt tell how to release it nor does you tube. so how does a guy go about this.

Dodsfall · 05-23-2012, 12:55 PM

"Vaporlock" is often misdiagnosed and the problem is most of the time caused by other issues.

What exactly is the motorcycle doing?

Edit: Vaporlock is actually when the fuel turns to a gaseous at the fuel pump, un-priming it and stopping the fuel flow. It's not a problem in gravity-fed carb systems.

77XS7502D · 05-25-2012, 12:22 PM

the bike over heats and i know its running on two of its cylinders, what caused it to over heat was the first exhaust pipe came loose off the head and it couldnt smog the first cylinder properly so it the exhaust was forced back in. it will still fire off, but i know its on two cylinders

Dodsfall · 05-25-2012, 01:44 PM

Air leaks in the exhaust can cause a lean condition with the fuel mixture, overheating the engine and causing damage to the internals, including spark plugs and valves.

I'd recommend getting the exhaust repaired before running the engine, since it sounds like there may have already been damage done.

Pull the spark plugs and check the condition and color of the electrodes to see if that is the issue.

You might check the compression on each cylinder to make sure that the valves aren't damaged and are still sealing properly. (That would explain why the cylinders aren't firing)

77XS7502D · 05-29-2012, 11:17 AM

changed the plugs out, that cleared it right up, they were fowled from over heating. but now maybe you could help me with another one. while on a test run with it. the bike ran fine. then i screw up with shifting. rear tire locked for a second then released engine cut, and now its locked. and the kick wont move at all.

05-23-2012, 12:46 PM	#1
77XS7502D Master At Arms Join Date: Apr 2010 Location: Riverside, MO Posts: 160	XS750 carburetor vaporlock title says it all, but whats convenient my repair manual doesnt tell how to release it nor does you tube. so how does a guy go about this.

05-23-2012, 12:55 PM	#2
Dodsfall Administrator Join Date: May 2008 Location: Illinois, USA Posts: 15,976	"Vaporlock" is often misdiagnosed and the problem is most of the time caused by other issues. What exactly is the motorcycle doing? Edit: Vaporlock is actually when the fuel turns to a gaseous at the fuel pump, un-priming it and stopping the fuel flow. It's not a problem in gravity-fed carb systems. __________________ 2008 XL1200R To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. Last edited by Dodsfall; 05-23-2012 at 01:08 PM..

05-25-2012, 01:44 PM	#4
Dodsfall Administrator Join Date: May 2008 Location: Illinois, USA Posts: 15,976	Air leaks in the exhaust can cause a lean condition with the fuel mixture, overheating the engine and causing damage to the internals, including spark plugs and valves. I'd recommend getting the exhaust repaired before running the engine, since it sounds like there may have already been damage done. Pull the spark plugs and check the condition and color of the electrodes to see if that is the issue. You might check the compression on each cylinder to make sure that the valves aren't damaged and are still sealing properly. (That would explain why the cylinders aren't firing) __________________ 2008 XL1200R To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

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05-25-2012, 12:22 PM	#3
77XS7502D Master At Arms Join Date: Apr 2010 Location: Riverside, MO Posts: 160	the bike over heats and i know its running on two of its cylinders, what caused it to over heat was the first exhaust pipe came loose off the head and it couldnt smog the first cylinder properly so it the exhaust was forced back in. it will still fire off, but i know its on two cylinders

05-29-2012, 11:17 AM	#5
77XS7502D Master At Arms Join Date: Apr 2010 Location: Riverside, MO Posts: 160	changed the plugs out, that cleared it right up, they were fowled from over heating. but now maybe you could help me with another one. while on a test run with it. the bike ran fine. then i screw up with shifting. rear tire locked for a second then released engine cut, and now its locked. and the kick wont move at all.