# Low Compression Help!! KVF 360!!!!



## guimond47 (Oct 22, 2009)

hey guy my 360 ended up with just 15psi compression after a ride. ive honned the cylinder and got the rings replaced , no damge or cracks in piston wat soo ever. i slapped in the new rings today and still 15psi compression. like whats wrong with this thing. people say that a damaged valve can be the issue. but how do i check the valve to see if its that thats damage. i dont wanna order valves for nothing. HELPPPPP!!


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## filthyredneck (Feb 10, 2010)

Try doing a leak-down test.... it will give signal to where the problem is really quick. Theres a very good link on here somewhere that N20torious posted for me here not too long ago when I thought I had an exhaust valve stuck. Not sure where it went to, but I know it was put up AFTER our Labor Day ride out at River Run...hopefully this helps some. If I find it I will pass it over here for you.


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## phreebsd (Dec 16, 2004)

signs are definitly pointing toward the valves.


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## guimond47 (Oct 22, 2009)

hey what is a leak down test? can anyone explain to me step by step how to do this......


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## J2! (May 8, 2010)

A leak down test is where you pump your cylinders up with air and see if they leak down after a period if time.. They make a peice that you screw in where your spark plugs go, then you turn your motor where the piston is top dead center and pump it full of air.. Since your piston is all the way up, if it leaks down, then you either have rings gone bad or valves stuck.. After you pump it full of air pull your dipstick out, if there is air coming from the crankcase you have a problem with your rings, if you have air coming through your carbs, you have a valve problem.. Hope this helps..


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## phreebsd (Dec 16, 2004)

^good post


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## Roboquad (Sep 8, 2009)

When the head is off you can check the valves with pressure, flash light, or even liquid. Push them to see if they slide easily and don't get Hung up. You also mentioned slapping the rings in, did you follow the alignment sequence properly. As well as top to bottom rings,should have been marked in your package.


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## guimond47 (Oct 22, 2009)

hey guys. thank for the help, where would i buy a leak down tester? and i took apart the valves and everything looks good. new rings are aligned properly with 40 degrees apart from each other. this quad is a head ache. anyone know how to make a leak down tester because i neeedd one.


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## filthyredneck (Feb 10, 2010)

The best deal I've seen for a leak down tester is through Harbor Freight...you can order it straight off of their website, its less than 40 bucks if I remember correctly, and would use air from your air compressor


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## guimond47 (Oct 22, 2009)

theres no way i can make one myself?


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## wolf_36 (Jul 7, 2010)

Might come out cheaper just buying one ,, don't know but some parts stores have rent a tool or loan a tool (like Autozone or Advanced Auto)


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## Roboquad (Sep 8, 2009)

Napa rental, the harbor freight one is a POS. I know I have it....


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## guimond47 (Oct 22, 2009)

hey boys turns out it was a valve issue. i took em apart cleaned them and all a sudden 180 psi. now im doing jumping jacks Thanks for all your help. really apreshiated!


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## Roboquad (Sep 8, 2009)

any time..thats why this sight rocks.:headbang:


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