WR400 99, clutch basket bearing, frame sand blast and paint job

wr 400 1999

Last race, 2,5 hrs in 3 hr run some noise began shattering the yammi.

tore the bike down, engine not yet completely apart, will do today.

Anyone had that bearing gone & is it typical failure for that model.

Top end is untouched, probably some gears will need change too and complete flushing.

Other thing, since I kicked engine out, also took apart everything touching or bolting to frame to paint it black.

First I'd have it sand blasted but need help on how to clog the oil line holes in the frame, to prevent sand coming in.

Upper oil pour hole, frame side hole and lower hole with oil strainer.

Also any ideas on protecting the 3ple clamp bearings housing?

Paint job will consist of zinc bathe, to prevent rusting and after that some plastic type layer of black colour will be added.

Supposed to be very tough, but if penetrated with stone hits, zinc coating would further the protection.


For the oil filler hole, go and buy yourself a standard case oil filler plug, it'll fit and when you're done you can throw it out.

For the drain plugs either leave the stock plugs in place and replace with new ones after you're done or replace with bolts of same thread pattern beforehand, keeping the copper gasket in place - you don't want to get zinc or plastic coating on the sealing/Mating surfaces anyways.

For the bearing housing, a long bolt with large enough washers to cover the top and bottom should work - you don't want it to be built up thicker on the top/bottom surfaces either. If you're worried about getting/leaking zinc into the bearing chases because the seal may not be perfect, put on a thin coat of gasket maker before tightening the washers down with the bolt, it'll scrape off easy enough when done.

Opened engine, nothing gone in there except for broken clutch plate finding its way into clutch gears.

Complete bearings and o-ring renew are to be taken and two driven gears also seem a bit chewed up.

SInce top end is relatively easy to fix (new piston an cylinder nykasil coating), and since main berings are going new, is it advisable to also change the lower conrod bearing and also conrod to 426 type, for its better durability ?

Ill take that paint info, thanx

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