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2006 SX-f 250 Engine Rebuild

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Doing a rebuild on a buddies KTM and have a few questions:

 

To Hone or not to hone:

I know that the cylinder is plated and suggest not to hone. The cylinder looks good, am I ok to just leave it. I will be putting in a new piston from ProX.

 

Crank Shaft Shims:

Any one know of a good way to determine what size shim will be required on the crank shaft with out the fancy gauge tool. I just ordered a bunch of different sized shims and figure I would start small and keep adding till their is no play. 

 

Valves:

The vales have some carbon build up, any suggestions in cleaning them or are they coated too?

 

 

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one thing to add to your list is the cam bridge. The bridge has no bearings on the side away from the gear. This side is metal to metal with an oil bath. There have been numerous failures there due to dry start ups or not enuf lube. So, be careful and use assy lube or sufficient oil. When I ruined mine I found this out. Also, they can be hard to come by as the failures were common after rebuilds. Mine also smeared the alum onto the cam and it was tuff to get off....FYI

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throw that shims away ,and use no shims at all . set the cambidge bolts ant 2 nuts to 12.5 n/m and no more (most manuals say,s 18 ,but this is to match

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No Shims on the crank shaft? If i don't the shaft will have some noticeable play from side to side. Can't see that being any good. 

 

Thanks for the tip on the cambridge

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site play dond. t care . buth most time the inner bearing race come lose on the crank shaft and this will distroi the shim . we ride ktm sxf for more than 7 years now and rebuld sxf engine,s 20-30 a year . our sxf 350 sizeds 3 time,s through this crassy thin shims . you cant make a shim from thin sheet metal . it is to week . but  go your own way . the same with the stock hydrolic cam chain tensioner . we dond.t even start a new bike with it . we replaced it from new with a manual one . believe me , the factory bike,s dondt. have shims and hydrolic tensioners.

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We'll speedboot you make a very good point. The whole reason for the rebuild this time was that the shims were just mangled.

Did you do anything with the cylinder, replate, hone or just leave as is?

Thanks for the info and tips.

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replating over here in the netherlands cost almost the same as a new oem cilinderkit . most time you can hone it to a smooth finish . puth a new piston in it and go.

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