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Idle problems, and maybe low compression?

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I have a new to me 2002 DR-Z400s. The story I got from the prior owner is that it sat with a failed petcock and filled the motor with gas over a few years. He drained the oil/gas mixture, put in new oil and was able to fire it up. He ran it for me but I think the idle was set high.

I'm now going through the bike trying to make sure everything is ok, but I'm having a hard time getting it to idle.

So far I've put in a new battery, changed all fluids and filter, checked the valve clearance, checked the spark plug color/gap, cleaned the air filter, and put in new gas. I was unable to get the bike to idle so I rebuilt the carb (thinking it might be a clogged pilot).

After putting the rebuilt carb back on to no avail I ran a compression check which showed 60 psi. Yikes, but then I read about the automatic decompression. However, the factory manual says that with the decompression enabled I should still be getting 135psi.

Any ideas? My last ditch attempt (tomorrow) is to spray starter fluid around the carb in case there's a vacuum leak.

One last note is the prior owner did the 3x3 and a new exhaust, along with a 150 main and 22.5 pilot. I dont know the needle. I've turned out the pilot 3 turns.

Thanks for any ideas!

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Ideas? Yes. Good possibility the rings are stuck from the gas residue.

Cylinder leak down test is the thing to do. Or you can carefully wire or wedge the auto compression release in the disable position (flyweight out) and try a standard compression test again. You will need a gage that seals to the 10mm spark plug hole for a leak down or compression test.

Also a good idea to inspect the auto decompression release to verify it is working and not operating at random. Also a good idea to verify the auto cam chain tensioner is not broken and the cam chain has tension on it. A 2002 model should have a replacement manual tensioner fitted.

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check silly things like have you connect all the pipes? vacuum ones like carb to air box, etc... air leak on rubber? airbox?

i remember there was one time when i rebuild by bsr36 i forgot to put the spring(on top of the slider) back in and it ran like shit... maybe that maybe not

hope it helps

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What they said^^

Plus

Check with the PO if he installed a jet kit....if using stock needle with 3x3 and open pipe it will be way too lean....

And use 22.5 pilot jet with extended screw or 25 pilot jet with stock screw..

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