[flightops]

Wwlcome to the club:

Although its not a club anyone actually wants to be a part of.

excessive oil consumption. They all seem to get there sooner or later. Oil burning messes things up right proper.

needs new rings and valve seals as a minimum: https://www.mini2.com/threads/p0301...re-lots-done-code-remains-where-to-go-next.369652/?post_id=4546909#post-4546909

 

[flightops]

Yeap, that's why I swapped the head for a rebuilt one

That much carbon buildup in the exhaust ports indicates the piston rings are likely worn out too. the oil scraper rings, not the compression rings.

These little engines aren't like what we're used to in one of the NA designs where you can replace a valve seat, guide, etc and not have further problems for another 40-50k. they're essentially "minimalist" engineering, cut to the bone everywhere. light castings, small parts, barely adequate strength timing gear, fussy on parts quality and functioning, etc. Just enough to do the job and get it out of warranty and little else. When they start to go, it's mostly an "all or nothing" type of rebuild if you want them to put any more significant mileage on them without further problems.

If you're over 100k or so for mileage, you're well into rebuild territory. As in: all or nothing.

Good news is the bottom end on these little buggers is pretty much bullet proof. Built like a tank, at least for what it's intended for. Deeply skirted block, cracked rod caps, integrated main girdle, cross bolted mains, etc so they can/should go a long time. Essentially, no need to touch the crank and bearings and even teh rod bearings are usually good to go for reuse. Same with the low friction rings: crappy oil scrapper design, but usually very little bore wear, if any at all. Mine had no appreciable wear or taper. Pop the pistons and rods out, quick hone, new pistons and do another 100k or so on them without issue. The heads though.....well......yeah.

I'm out.

Good luck (sincerely).