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Posted: Thu Dec 04, 2008 1:47 am
by cannondale27
Why is your compression between 70 and 120psi?It should read a specific psi not a varying compression.Are you holding throttle wide open when doing test.Crank it over 5 or 6 times till needle stops going up.Thats your compression.If you did that and once it read 70psi and once it read 120psi your decomp might be shot or a stuck valve.Take about a tablespoon of oil and pour it into sparkplug hole and do compression test again.If it goes up your rings are wore if it stays low it could be a valve or decomp.
Posted: Thu Dec 04, 2008 2:09 am
by Rookiex
o no i was just replying to someones post they asked whats the normal compression for a test.
Posted: Thu Dec 04, 2008 2:12 am
by cannondale27
So you didnt do a compression test yet?
Posted: Thu Dec 04, 2008 2:28 am
by Rookiex
No I dont have a compression tester.I left all my stuff when I moved to florida at my mom and dads.Kind of sucks.God I guess ive been dreding doing it because of what I might find out.Ill have to pick one up from the auto parts store tomarrow.
Posted: Thu Dec 04, 2008 11:04 pm
by MX Quad Dad
o no i was just replying to someones post they asked whats the normal compression for a test.
The reason I posted it like a question is because, the decomp. would make it lower than one would expect and if you didn't have at least that it could be why you can't get it to fire.
You have made sevreal comments that it is cranking over fast, so I was thinking if the decomp. broke and holding the valve open a little, it may be enough to drop comp enough to prevent it from fireing up.
I can still hear my Dad telling me "if it's got gas, spark and compression, it should run". I always added, timming to this because when I would finaly listen to him and check for all three. after that it was just a matter of timming.
I know these thing are high tech but without the basic three that high-tech dosen't do any good.
Also to much fuel isn't good either
Posted: Tue Aug 18, 2009 5:05 am
by proflow
I just tore down my wifes Speed with the same symptoms. I found the timing chain guide itself snapped & skipped timing just enough to cough & tease me ! Luckily no other damage. Might want to check your tensioner to see if there is something going on there---Proflow
Posted: Wed Aug 19, 2009 4:26 pm
by ACEwrench
....did you get er fixed????
Posted: Wed Aug 19, 2009 8:26 pm
by jesshamner
I don't think Rookiex cares as it has been a year since before yesterday.
Posted: Thu Aug 20, 2009 2:28 pm
by Z4J
Interesting. I believe this is the quad I own now.
Problems found after the tear down-
Trans filter gobbled up
Small trans oil gears were marred and jammed
Wrist pin seized
Piston/rings/cylinder were heavily marred (w/ zero compression)
Rebuild to start this weekend. As always, thanks everyone for the support through this-- especially Dave, Pete, 27 and Tim.
Posted: Sat Aug 22, 2009 3:39 am
by Trouble
sorry to hear that,hopefully you knew what you were buying,good luck with that anyhow