250F Pulled off my head, are these parts good or bad?

Mihylo33

Mihylo33

timoyz:
Have your seat cut, don't lap them in. There is a coating on your new valves, lapping heavily will remove that coating. Whoever does your machine work, will lightly lap them in as the final step.
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That's good info! Thanks Timo. :thumb: big difference between these F1 motors and the old 4ts I am used to.
 
Y

yamadogyz

the other day i pulled some protection off my head.. i was interested to find a large amount of sticky stuff on the inside too. nothing a little simple green couldn't fix!
 
cleonard

cleonard

You don't really need to hone much if at all. It's not an iron sleeve. It's a really hard plating on the aluminum. If there are still crosshatch hone marks it may just need some vigorous cleanup with soap and a Scotchbrite pad or two . Unless the engine is high time a hone is not usually needed and can be a dangerous operation.

Clean that bore first and post some pics as I doubt you need to hone.

Here is a great document about doing a modern four stroke top end. http://www.eric-gorr.com/pdfs/4 stroke.pdf
 
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