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Main Area => General GS500 Discussion => Topic started by: bosozoku on June 18, 2007, 07:31:22 AM

Title: Burned valves?
Post by: bosozoku on June 18, 2007, 07:31:22 AM
So anyway, to continue the saga of my bike -- the vacuum readings of the left cylinder are bouncing up and down a lot as compared to the right -- also, it pulls quite a bit less vacuum to begin with.  The left cylinder was running very lean before due to stock jetting combined with K&N lunchbox/Yoshi pipe.  The right wasn't due to the fact that some bright boy had drilled out half the pilot jet on the right carb, causing the cylinder to run super rich and burn gas at 20 mpg.   :mad:  Could I have burnt valves in the left cylinder, and is it worth yanking the heads to find out?  I double-checked valve clearances yesterday -- all were greater than 0.03mm cold, so the problem is NOT a valve that doesn't close.  Grrrrrrrrrrrrrrrrrrrr.

-b.
Title: Re: Burned valves?
Post by: gsJack on June 18, 2007, 07:41:45 AM
Quote from: bosozoku on June 18, 2007, 07:31:22 AM
:  Could I have burnt valves in the left cylinder, and is it worth yanking the heads to find out?  I double-checked valve clearances yesterday -- all were greater than 0.03mm cold, so the problem is NOT a valve that doesn't close.  Grrrrrrrrrrrrrrrrrrrr.
-b.

Check compression first before pulling head, if compression is good the valves are OK.  If you don't have a compression gage you can use the old finger in the hole method, that'll tell you if valves are the problem.