2006 gt250 high lkm club compression test values
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After deciding not to run the bike for a period until I can fix the ticking as in the videos, I have performed a compression test on the cylinders, dead cold, wide open throttle both spark plugs removed. After searching this forum I have found them to be a bit low from spec. Probably since its cold.
front cylinder
rear cylinder
ticking from side 1.
Sorry for such a short video as the website cannot handle a medium sized walk around of the bike.
I have installed new cam chain tensioners, but may have bent valves from hitting the piston, which may be the sound of ticking.(even though its more than a tick)
I am inspecting a replacement motor tomorrow as I lack the skill to rebuild an engine. Though may be buying more trouble. -
I found my borescope today and investigated into the spark plug holes of each cylinder, the front one may be hitting onto a valve as there is a silver/ligher circular area on top of the piston.
The rear one is just heavily carbonized, but no detectable contact. Here is a short video of.
Not sure what to do, the second hand motors I am looking at apparently have no history.
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For videos, you can always upload them to youtube as “UNLISTED” , it means it won’t be found on youtube searches , but copy their share links and paste them on to the forum here no problem.
If you have gaskets for the cylinders , it would be a wise call to remove the cylinder heads so that you can see that all 8 valves are sitting flush or if there is too much carbobn deposits on the valve walls, stopping the valves from fully sitting down, after the cam lobe stops pressing them down to the pistons.
The clearance between a piston going up and a valve going down is small indeed , from the video it is hard to tell if the valve is actually hitting the piston or it could just be factory dentures so that valves don’t fully hit the piston.
Compression should be about 150 psi hot, did you test this when it was hot too ?
Ticking noises = funny you said tensioners changed , what about chain? or valve tappet shims? unless you have 1 shim basket that’s rattling under the cam lobes? (I hope not)
I have a feeling you will want to rebuild the 2nd backup motor fully , before taking apart the live one that’s still working inside your bike. Could i be wrong?
// Meditation doesn't mean you have to sit still....
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2006 GT250
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