Low compression / Sticky valve on 05 YZ450F

I suspect a heavy carbon build up on the backs of the valves. Assuming you gave your measurements in English units, a clearance excess of .004" isn't enough to let the shim jam as you are suggesting, IMO.

Yeah after thinking about it your probably right.....What do you suggest for

the carbon build up.....

Maybe some products out there that can remove the carbon?

Maybe some products out there that can remove the carbon?
Not by name off the top of my head. Go back to this:
there are "top engine cleaners" that do a good job. One of the best available is from the GM parts counter, imaginatively named "GM Top Engine Cleaner". But like all over the counter GM chemicals, it's pricey. Most TEC's are basically the same stuff as "Techroline", and are already present in the fuel you use in small quantities.

Sounds like I will be taking a trip to the Chevy dealer tomorrow.....

Thanks, BC

I just got back from a weekend at Stonyford and 450 ran perfect. Started good

all day and was perfect. I used the Seafoam the day before we laft and the

stuff really works.....Thanks Guys.....


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