Valves going bad

[GSJimbo]

Whats the biggest sign of your valves going bad? popping sound? thumping sound?........or what??

[cbxchris]

Losing valve clearance. Over 10% leakdown when doing a leak down test.

[gsx1100e]

How do you do leak down tests.

[Detman101]

I think he meant "noticeable when riding" things.
Something you could tell/notice while riding the bike.


Dm of mD

[Billy Ricks]

A leak down test involves pumping compressed air into each cylinder with the valves closed. You do this through the spark plug hole. You pump in a measured amount of psi then measure how quick it loses pressure. You can also listen to intake and exhaust ports and the crankcase through the oil fill cap to see where the air leaks from. There are kits for this. You can also make your own, do a search and you'll probably find a home brewed test kit and instructions on how to do it.

[GSJimbo]

Yes I meant while riding or while at a idle,popping or a thumbing sounds??
Through the exhaust or carbs??

[RacingJake]

Valves don't make thumping sounds, rods do. Not unless a piece of valve has broken off and it's still in the cylinder or cam timing is off. I'd do a compression check first and look at all the plugs and see if they are the same color. You can always pull the valve cover off and check the cams, caps and rockers. Also check cams timing and the cam chain tensioner.

[GSJimbo]

Did a compression check and found 160-150-100-110, guess I need a valve job!!

[cbxchris]

Could be the rings. You need to do a leak down first to see where your problem is. Plus you could just have a lot of carbon on your valves. Easily removed by several products that you can run through your fuel.

[GSJimbo]

just rebuilt it , cleaned all valves, doing a leak down test this weekend, I could have a broke piston ring! we will see..........