'99 420 overhaul update

F.Y.I. and the sharing of costly experience.

1/ Cases split, lower crank bearing shot, .015''axial play at least. Crank is blue at lower bearing. Was like this at rebuild over winter. At that time there was no play. Is the blue normal as in induction heating for installation or did it get hot from riding / wear / contamination?

2/ Piston / rings shot, bore may be salvagable as aftermarket oversize plating by very reputable shop here in Quebec ( A. Bernard )seems to have withstood the abuse of contaminated oil. Apparently harder than the stock Nikasil.

3/ Tranny in very good shape, was not able to locate source of .030'' x .075'' x.150'' broken off chunk of tempered steel that I found on the magneto. I think it may have come from a bearing. Will know over weekend.

4/ All bearings will be replaced, some were running rough.

5/ Observed that most parts such as crank, gears, etc. have lots of sharp / rough edges that seem prone to maybe breaking off and doing another number in my motor. Dremel time was spent here! Manufacturing quality / detail seems inconsistent. Quite dissapointing compared to my '79 YZ125, 3 seasons constant riding as an irresponsable teenager back then with just basic maintenace, no probs.

Hope some of you can put this info to use. Thanks for your time. Will fill you in later when running!

[This message has been edited by Hugh LePage (edited August 30, 2001).]

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