Piston and Ring Question

[douglee25]

According to the Polaris manual, the sl750 should have a piston to cylinder wall clearance of 0.004 to 0.006 inches. I believe the ring end gap (hope this is correct from memory) is 0.008 to 0.018 inches? Anyway, I just had all three cylinders bored .020 over and he matched each cylinder to each piston. I checked the ring end gap on one cylinder and found one ring to have a gap of 0.023 inches and the other had 0.014 inches. I suppose the difference comes from a quality tolerance with WSM. Personally, I think that 0.008 to 0.018 is quite tight for a 2 stroke end gap. I remember rebuilding 2 stroke dirt bikes, and their rings gaps are usually 0.020 inches or so, but that's besides the point.

Does anyone see any issues with the difference in ring gap? Is there a preference to have the tighter ring gap on the top versus the bottom on the piston? Let me know your thoughts. Thanks for your time.

Doug

[Technical Support]

Re: Piston and Ring Question

Ring gap should be between 0.010" - 0.016". We average about 0.013"

If you run a 0.023" it will have excessive blow by, I would get another.

[douglee25]

Re: Piston and Ring Question

Ring gap should be between 0.010" - 0.016". We average about 0.013"

If you run a 0.023" it will have excessive blow by, I would get another.

Ok, sounds good. I will try and see if the rings fits better in another cylinder better than the first one. Otherwise I guess I'll have to call and get another set of rings sent to me.

Doug