Riding home with the missus after being out for a few hours and a nice cool day yesterday.

I passed a cager that was poking along, when a big *POOF!* of white smoke bellowed out my right muffler (front cylinder), and subsequent puffs as I coasted to the roadside. What I found odd was that the engine wouldn't shut off, even after i hit both kill switches. I had to stall it with my clutch once I got pulled over. Oil still quite full, no external leaks. The front cylinder just smoked like hell & went dead. The rear cylinder was still firing though, and the engine would still start & run (BARELY). Fortunately a buddy of mine is in a prominent MC around here, so he had a trailer & a trustworthy repair guy to take it to. We're dropping her off tomorrow, hopefully the damage isn't TOO bad, but we'll see. 64k miles, and I'm often not gentle with it. A friend who's a respectable Harley wrench suspects front piston rings at MINIMUM.

*SIGH*

 

Might be a bent or dropped valve with a corresponding hole in the piston.

 

I didn't hear any noise? I would suspect a valve smashing around inside the cylinder makes some pretty serious racket, but I'm no expert, that's for sure.

 

I'm curious. Hope it's not too bad.

 

Curious as well….hopefully not too bad.

 

The "wouldn't shut off" part is puzzling.

You hit the kill switch AND shut off the ignition (key) and still had to mechanically stop the motor?

Weird.

Do keep us posted as this unfolds. Very interested in seeing what it turns out to be.

 

You know when something hard mechanical cuts loose, there's no questions. Sounds like the rings shattered or badly damaged piston with a hole or grooves past the rings, they get real hot they will diesel sucking oil from the crankcase making it hard to shut down.

Smoke like crazy when they do that.

 

Update...

Leakdown test was performed, rear cylinder was blowing air into the crank case which suggests either rings or a hole in the piston.
Front was blowing air into the intake, which suggests a bent valve.

The tech is gonna check again to be certain, then he's gonna pull the heads and see what's actually happened. He also said the rear spark plug was completely jacked up, the electrode was loose. Which is weird because those are fresh plugs, maybe 400 miles ago.

 

 

It's coming completely apart, get your head around that now and plan accordingly as it isn't going to be a cheap fix if things went that catastrophic inside. Busting the porcelain in the plug says something was rattling around in there, that will beat the **** out of everything including hammering the crank pin & bearings not to mention all the nasty that got blown into the crankcase, oil & oil pump.

Start deciding if the bikes worth it to you.