Hello all. I have a 2010 sf model with over 25k miles. I just noticed the cams and chain are way out of spec, wondering how would I measure the wear on the cam cap and head journals where the cams ride. Looks to be this bike will be another money pit and trying to figure out if the bike will be worth it after fixing the 351 issue I'm having. Does anyone else make cams besides Web. Ive looked everywhere and did a search but haven't come acrossed. any. If not, which spec cams are recommend for the 351. thank you

 

Typically one would use a micrometer to measure these things.
If you haven't measured them, why do you state they are way out of spec?
Specifically, how did you determine the chain was OOS?

 

I'd be curious too. Why do you think everything is worn out and don't go spend a bunch of money before you know you need to do so. If it is noise in the cam drive you likely need a new tensioner, manual holds up for ever, OEM may crap out in less than 10,000 miles. Many here will tell you that once the manual tensioner is adjusted properly any noise virtually disappears, cams are in proper timing, and I'm betting a lot are like me, not having to adjust the cam drive slack yet - several thousand miles or more later.

Those HyVo type chains run tens of thousands of miles in so many bikes I just don't get one wearing that fast. The two reasons they are used are they are extremely durable and they run quietly in comparison to standard roller chains. In other words they wear very slowly. Get a manual, they can be found for free online and measure the cam chain for wear per the manual. Only way the cams and cam journals would be worn would be if run low on oil and starting to seize up. They run on oil, not metal to metal.

As said, you will need a proper size (0-1 or 1-2) micrometer to measure the cams, then either a bore gauge or a snap gauge (micrometer measures over the snap gauge) that can measure the journals with the cam cap in place.

I've run over 35,000 miles on a similar HyVo cam chain set in my KLX650 with no wear issue, minor adjustments of cam chain slack adjustment less than .012". I've had some Concours riders tell me they've gone tens of thousands of miles without adjustment. The chain runs in a constant bath of oil and with correct chain slack (near zero slack but not tight) they should last as long as the engine lasts.

 

Thank you for the replies. You are both appreciated. I measured the cams with a micrometer. Both cam gear side lobes are worn. intake 13.7 exhaust 13.05, The cam chain is stretched not allowing proper alignment of the cam gear markings to head. The previous owner had a mcct installed way to tight. Also see wearing with head and cam cap on the gear side of where the cams ride in. also checked the cap for blockages on oil channels and are good. Back story on the bike, I bought it right after the previous owner put a 351 kit in it. It was making head noise and why I tore it down, it was missing an exhaust shim (hoping he didn't drop it in the engine). Also missing the head and cylinder dowels, 2 bolts in the cam cap and the 2 outer head bolts lol. The guy never rode on the 351 kit and shows excessive wear for just start ups, Noticed the wrist pin had a wear groove and rings look worn on the exhaust side, possibly no heat cycles or who knows how this guy treated the fresh rebuild.

 

That engine sounds ... wild. Still can't believe the cam chain is wore, but you're there. I'd find out if he split the cases, if he did, you got problems there too probably. Otherwise sounds like you're on it.

 

Sounds like you would be right, and know the deal on a manual tensioner. Better to be a bit loose than too tight. Seems some don't get it - the noise is a symptom, not the problem. The problem is cam drive issues that affect cam timing and can damage parts, especially if it allows the cam chain to jump a tooth. I would recommend you get a snap gauge and check out the journals to see if there is too much clearance.

If you do need any information on the manual tensioner you can find it under the cam chain tensioner sticky in the KLX250 sub-forum.