Engine stripping and rebuilding advice

nate · Post by **nate** » Mon Jan 21, 2008 2:29 pm

Hi all,

Ok now that the pesky carbs are sorted, my bike is complete

So, my next job is to look at my spare engine. Its a KR-1S engine and my plans for it are

1) strip and check bearings, barrels, stuff like that

2) tune it a little following MJ's advice and piccies

3) give it a damn good clean

4) Maybe have the cylinders skimmed so they are the same height like PB did to there little KR

However, I have never done anything like this before, and am terrified of snapping PV's and generally screwing up a perfectly good engine. Though I like learning as I go and have a good amount of common sense and the tools and garage to do it in...

Anybody got any advice on specific areas to watch out for?

Should I start with taking off the cylinders and then go from there.... or start else where?

cheers

Nate

mgtkr1 · Post by **mgtkr1** » Mon Jan 21, 2008 8:40 pm

first of all, soak the powervalve screws in pen-ol a very effective penetrating fluid. the p/vs are prone to snapping when force is used to undo the screw. some people say remove the head/barrels as a unit effectivly just undoing the 8 nuts at the base of the barrels. its a handy way to save a head gasket and reduces the chance of a warped head. as your strippin/replacing gaskets it doesnt really matter, just undo the head bolts in reverse to the numbers, going round them patiently. allow a couple of circuits of the numbers rather than undoing them individually in one go. again saves the head been distorted more than absolutly neccessery. when assembling the top end you can either torque the head to barrels half way then mount to the motor then finsh of the torquing up sequence as numbered or mount barrels seperate followed by head then torque up in the numbered sequence. BE VERY CAREFUL when torqueing the head down, as it distorts very easily resulting in regular head gsasket failiure. some people say go round all the head bolts 3 times doing it bit by bit. i say 5 times as i have not had a problem doing it this way yet, wether bolting top end on as a unit or doing it all seperate. the fitting of a top end is a boring job except when p[utting on diffrent spec barrels to try $\:D/$ but requires patience as this will pay dividends in the long run.

nate · Post by **nate** » Tue Jan 22, 2008 3:58 pm

Hi all,

well got the head and cylinders off my number 2 engine today...

The cylinders look good

And dont look like they have been fiddled with...

However, one of the cylinder heads looks quite pitted ... Is this bad? What is the cause and can / Should I do anything about it? [-o<

Also, anyone got any adivce on getting the two shiny box things off the side of the cylinders so i can degunk and give them a good wash out?

Cheers

Nate

mr_bungholeo · Post by **mr_bungholeo** » Tue Jan 22, 2008 7:32 pm

think out of about a dozen heads ive only got 1 that never went pop so its not a problem...as long as you make sure that its got no high spots that can whack the piston but if its been running on it its probably not a worry..try a bit of heat and a stiff tap with an old 6mm socket on the bolt head on the covers...best of luck...