Cylinder wall scratch

Discussion in '2-Stroke Engines' started by Bogaurd, Sep 14, 2008.

  1. Bogaurd

    Bogaurd Member

    Hey guys,
    Had the head off my 80cc tonight, noticed a couple of very small (less than 1mm) scratches on the nikasil coating of the cylinder wall. They're right at the top of the cylinder, and my guess is that they might have occurred when the engine was started for the first time, given that the cylinder wouldn't have been oiled at that stage. The bike has probably done a thousand km or so, and I'm not having any issues, loss of power etc, so I figure they're probably harmless. When the engine eventually gives out I'll either buy a new piston, jug etc & do a rebuild, or just put a new engine in.

    Just curious to see if anybody else has noticed anything similar... I'll get some pics up at some stage so you can see what I mean. :smile:

  2. arceeguy

    arceeguy Active Member

    If you can catch your fingernail on it, you should probably do something about it. I'd hone the cylinder and re-ring the piston. For chrome or nikasil plated bores (I think the HT is chrome) use a 240-320 grit Aluminum Oxide flex hone. Just 10 strokes with the hone will clean up the bore nicely.

    On the other hand, if it runs good - just run it until it dies! If you never head the head off, you never would have seen the imperfections. So put the head back on and "out of sight - out of mind."