KR-1S.co.uk Forum

HI FELLA I HAVE A SPARE SET OF CRANKCASE HALVES AND I NOTICED THAT TWO OF THE MAINBEARING HOUSINGS HAVE STEEL INSERTS. I SEEM TO RECALL SOME TIME AGO BEING TOLD THAT THESE ARE THE "LESS FAVOURABLE " kr1s cases?(DONT SHOOT THE MESSENGER I`M ONLY REPEATING WHAT THE KR OWNER STATED)

The Engine Number is KR250 BE--000202 ANYONE SHED SOME LIGHT ON THIS QUESTION????
COL.

That low a number would indicate a KR-1 crankcase set rather than a KR-1S set.

Thanks for the reply Gerrit just goes to show you should take someone`s comment with a bit of salt.
Do you know the reason why they put these steel inserts into the casing as they are not in later kr1 crankcases??
col

Yes the 1s has steel on the right side bearing, not sure what makes them "less favorable" as you put it LOL, but the aluminum around the insert usually delaminates, i doubt they left the factory like that.
Like gerrit said, that number will be kr1,so no steel :/, maybe you read the number wrong?

Yes the alloy skin on one bearing is delaminating but that number is right I can show you pic
Knowlerceekay@aol.com.

Kawasaki used steel bearing inserts in S1, S2, S3, H1 and H2 crankcases and they are still going strong. I don't see a problem with the inserts. I'd definitely prefer cases with steel inserts as they are less likely to lose the bore tolerances.

Good point Gerrit but makes me Leary about where those tiny bits of flaking alloy end up.Probably in the roller bearing race next door
Col