'08 YZ 450 Valve Check 20 hours

I've got one intake at .09mm and one exhaust at .19mm, both left side and .01mm under spec. Unfortunately I didn't do a base line check when the bike was new so not sure how much they have moved. I'm thinking about putting 3-5 more hours on it and rechecking to see if they have moved. Any thoughts if this is a bad idea? Bike still starts great, no problems. Thanks.

.01mm is .0004". Are you really confident that you can measure that small an increment with a feeler gauge?

Even if you are, I think I'd call those .10 and .20 for the time being.

.01mm is .0004". Are you really confident that you can measure that small an increment with a feeler gauge?

Even if you are, I think I'd call those .10 and .20 for the time being.

Good point. I'll do a recheck in 5 hours and report back any differences.

Thanks Grey:thumbsup:

I just finally got around to checking mine. 100hrs and exactly spec! Gotta love Yamaha!

I checked mine on my 08 450 at 25 hrs. My exhasut were perfect, I had two intakes that were tight at 9 and one at 10. Book says 10-15, so I set all my intakes up on the high side, but still in range. Should be good to go for a while.

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