'06 KDX 200 High Compression

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RustyHama
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'06 KDX 200 High Compression

Post by RustyHama »

I picked up a compression tester to check the condition of my top end. Stock compression from the service manual is 95-151 PSI I scored 180. I hadn't warmed the bike so I warmed it then tested again - 180! I've done a search and found some discussion on this so I'm going to assume 1 of 2 reasons for this. Non stock high compression piston? Don't think so cos' I've never heard of these for a KDX. The more likely scenario is carbon build up in the head and on top of the piston. Some where it says the easiest way to check is remove the exhaust and take a look inside.
Does anyone have any comments or warnings about this? I'm planning to use it on several trail rides between now & April then take the head off & check the top end over winter.

Thanks
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s10gto
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Re: '06 KDX 200 High Compression

Post by s10gto »

Also it could have had the head resurfaced or thin gaskets used. Most likely carbon. Just run 93 and you will be fine.
RustyHama
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Re: '06 KDX 200 High Compression

Post by RustyHama »

Thanks for that. 93 octane?... here in NZ we have regular 91 then Shell does 95 & BP does 98 all of them are unleaded. So are you suggesting a higher octane or lower?

I looked this up on Wikipedia the 93 in the US is equivalent to our 98 so that is what I'll use next time I fill up. Thanks!
s10gto
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Re: '06 KDX 200 High Compression

Post by s10gto »

Yes higher octane. The higher octane will stop pre-ignition.
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Re: '06 KDX 200 High Compression

Post by KDXGarage »

go with 98, as you guys don't have RON+MON/2, like we do.
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pumpguy
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'06 KDX 200 High Compression

Post by pumpguy »

How about gauge accuracy? Your gauge might be reading high. I would try another compression gauge just to be sure.
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kx200
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'06 KDX 200 High Compression

Post by kx200 »

my old 89 is always 200psi after a rebuild.
RustyHama
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Re: '06 KDX 200 High Compression

Post by RustyHama »

2 years on... I checked my compression yesterday, it's now at 150 (although the bike was not warmed up) so it's dropped 30 psi but spec is 90-150 so still in spec and the motor still feels sweet as! Maybe I'll check it again at the end of this trail riding season before I decide to do the top end.

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