MTFCA Forum

Honing and reringing a 26 tt oil burner,this is a low budget repair on a tt only used a handful of times a year.i bought oversized rings and am looking for thoughts on ring end gap,thanks

Depending on how true the bores are like within a few thousands, .012"-.013". Take the rings and size each cylinder for best results starting at the tightest point.

Hope this Helps,

Hank

Also be sure to check the fit of the rings in the piston grooves. If they have any perceptible up-and-down play, then that is very likely one source of your oil burning. If you can insert a .003” or larger feeler gauge above or below the ring, the piston should be replaced. I recently had an engine in the shop that was a known oil-burner and the up and down clearance of the rings in most of the grooves was .005”. The grooves were worn enough that new rings would have had about the same clearance and still would have been a smoky engine, even with new rings.

Don’t overlook worn valve guides as well. Intake valve guide clearances around.008” or larger can still seem to run alright, but will cause oil burning as well.

Assuming you are still using cast iron pistons.
Top ring .008" to .012" middle.006"to.008" and bottom .004" to 006"

Yes still using cast iron pistons.valves were done a few years ago .only use couple times a year it is a snowmobile.sat under a barn for who knows how long .uses 1 gal oil for every 6 gals gas ,maybe it's a 2 stroke.hoping to find broken or stuck rings.i know that sometimes people's experience is better than what you read .thanks all

If its using a “gallon of oil to six gallons of gas”, and there are no major leaks, then you must have a hole in a piston!

Or your pistons are TOTALLY SHOT...

A quart of oil in 75 miles is highly excessive...

Is your breather cap clear? Excessive crankcase pressure will blow oil out every where, even on a perfectly sealed engine.