Well, that's not good. (catastrophic failure)

[Firerunner]

I haven't torn it down yet, but my best guess is that the cam chain jumped a tooth. One minute I was riding along without a care in the world; the next, I was going 65 mph without a headlight at eleven o'clock at night on a dark country road listening to my engine do an impression of a trash can full of gravel.

The oil is full of chunks. I found the remainder of one circlip. From what I can see, it seems like I'm looking at the remainder of a piston skirt.

Whatever caused this made enough of a sudden jolt that it destroyed the new copper advance mechanism delete from my Pamco unit. I'll hit Pete up tomorrow about buying a replacement.

Luckily, I just bought a parts bike with a fresh professional (or at least, farmed out by a known judge of quality) rebuild.

My plan is to swap that into the bike while I rebuild this engine, likely with a rephase, MikesXS overdrive 5th, and some other goodies. We shall see once I get it open.

 

[angus67]

OHHHHHHHH!!! that's what I found in my engine when I cracked it open. piston skirts indeed. that crown is naked now. make sure you flush the hell outta that motor before you put it back together.
I whent thru 2 cases of carb cleaner getting it all out. buy some hand lotion, too.
I just found it cost effective to get the whole 1.5 over kit from mikesxs. new fins, jugs,pistons rings, all matched and rings checked by shop, low mile crank assembly, had thehead decked a bit, now its a 680. and twitchy as hell!!

 

[Firerunner]

Pricing that out makes me think that perhaps I should just invest a little more and get the XS performance 750 kit. Of course, that would put me at about $1,400.00 in parts with the rephase and od 5th.