Seeking guidance - possible valve issue

Yamaha YZ400 Yamaha YZ400F 1998

21 replies to this topic
  • NitrousR1

Posted July 31, 2013 - 04:56 PM


I use a snap on leak down tester at work just because of how often I use it. A great bang for the buck leak down tester is the OTC. Runs around $70 and seems pretty decent. The tech next to me in the shop has one and had zero problems so far

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  • ShsFunny

Posted July 31, 2013 - 05:34 PM


Thanks guys. I'll pick one up this weekend. I wanted to post this yesterday but I didn't get a chance but when I pulled my spark plug and replaced it, somehow I now have much more compression. I don't have to use the decompression lever still, but I can't put it through with my hand either. I'm definitely making progress here thanks to you all.

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