oil consumption?

[Fred Hink]

Out of those 30+ pistons have you ever checked the cylinder for out of roundness?  Eldon Carl believes (and I tend to agree with him) that some KLRs that use oil are because the sleeve on the KLR is supported at the top and bottom and nothing in the middle.  This extra large hole can distort the sleeve to where it isn t round any longer and it is hard to seal a square hole with a round peg.  Putting in an oversized piston in a new bore will usually cure the excess oil usage but for how long.  Just because you now have a round hole and a round peg, doesn t mean it is going to stay that way very long.  If fact I would guess that a big bore kit with a thinner sleeve would suffer the effects of heat distortion as quick if not quicker than the stock bore.   Fred http://www.arrowheadmotorsports.com   [b]From:[/b] DSN_KLR650@yahoogroups.com [b]Sent:[/b] Wednesday, October 08, 2014 10:34 AM [b]To:[/b] DSN_KLR650@yahoogroups.com [b]Subject:[/b] [DSN_KLR650] Re: Oil consumption?    

Paul Westman has done some very interesting work in reducing oil flow to the crankshaft which has reduced the oil consumption, increased fuel mileage and shown excellent oil results in oil analysis. The hypothesis seems so well supported by evidence that it may be more correctly termed as a theory.   I've seen some oil rings with chipped/peeling surface which might be the issue with some bikes. The 30+ used pistons I've inspected had several examples.   Another interesting case was a Gen1 which was a very bad oil burner. I pulled the top end and had the valves & seats ground because they were so pitted from the deposits. I deglaze honed the cylinder and left the rings because the end gaps were still OK. The oil consumption is back to typical, Just, FWIW.