Crankcase Corrosion

[jono]

am in the final stages of rebuilding the engine on my 1996 jtr 270. noticed alot of corrosion in the crank case, kind of brown mud looking substance but very gritty, may of been the cause of the engine wear.

has corroded max 2mm deep in places, mostly at the bottom, not in any structural places or bearing/sealing faces

am told this is the result of fuel oil corrsion?

i have always used fully synthetic 2t oil and decent fuel (not 6 month old lawnmower fuel) the longest the bike has stood still is 3-4 months.

are you supposed to flush out crank case or leave the drain plug out, when you leave the bike for long periods?

should the crank case be painted? if so with what?

so far i have bead blasted most of the corrosion out, and am waiting for my crank to have new rod fitted.

any info greatly appreciated

[magicmat]

im doing the same on my bike,...however there is alot of corrosion in the bottom of the ignition case, where water sits behind the cover and can corrode the electrics ?

My bike is a 1992, and ive had all the stuff fitted,,...crank etc.

But i was just going to prime the casings in ally primer, then paint with thick engine paint... is that alright ?

Ive been logging my progress

http://www.trialscentral.com/forums/index.php?showtopic=6244

[jono]

i think pj1 do some specific engine case paints for the external

i will leave the inside of the engine case bare (bead blasted)will paint the outside of the casings later.

do you know the tourque setiings for the flywheel? and the nut on the otherside.

[magicmat]

im not sure off hand, as im at uni,

but im getting my parts from <mention of this company is not permitted on Trials Central> and they told me that they would tell me all the torque settings so give them a try.

I dont intend on painting inside the engine, where the gearbos is etc,

just where the stator plate goes and then outside.

just having problems deciding what colour now !