1975 850T Survivor Project

[cmice]

Hey all - just got myself into a "barn find"/"ran when parked" project.  Last registered in 1985, last operated in 1991.  Apparently a stuck clutch is what took it off the road.  P.O. did a favor and drained all the fluids, fogged the cylinders, and stored it inside - so far, all the fasteners are coming out without too much of a fight.

Bike is pretty much all there, with the exception of the H-pipe and mufflers.  I'm not sure the Wixom fairing is going to stay or not, but it is growing on me.  Is a non-filter model, so that's fun.

Other things to fix are: broken steering stop, scored forks, bent crash-bar, and tired rubber (including tires).  If there's anything else you spot from the photos, do let me know.

I'll post my first question to the collective under this post.

Next up is to pull the heads as they are chrome bores and I'm pretty sure they're up to no good.

[cmice]

Pulled the flywheel cover out, and the ring gear has seen some action.  What do you suppose caused this?  Inside of the bell housing is unmarred, so I think the thrust-bearing/end-play is ok.  Looks like maybe the starter hit the ring gear while the engine was running and spun against it for a bit?

Use it, or bin-it?  Whaddayathink?

[Antietam Classic Cycle]

If the steering stop is broken off and the crashbars are bent, then I would check very carefully to make sure the frame isn't tweaked. Those are both good indicators that there is frame damage. I have three Tonti frames here that wobble side-to-side on a flat surface.

With only 23k miles in 50 years the chrome is going to flake from the cylinder bores if you run them. Sitting around is the worst thing for them. IMO, there is not such thing as "good chrome bores" - it's not "if" they will flake, it's "when". Replace them now before they destroy the engine.

The ring gear damage likely happened from a tankbag or something else accidentally hitting the starter button. It will probably work okay as-is, but a replacement wouldn't be a bad idea.

[cmice]

Today's update - figured I'll pull the conrod caps off and see what it looks like there as a quick assessment of how he's been treated. Mixed news.  The bearing shells look distressed but the crank journal looks great - at least on the center web anyway.  But the distressed shells mean the crank should come out and get checked, along with the front and rear mains.  Off comes the front cover.

By the look of the incorrectly folded folding-locks and the boogered up stake-nut on the crank-drive sprocket, someone has been in here before and without the right tools.  So here's hoping whoever it was treaded lightly.  Some additional good news is no stripped threads or helicoils anywhere - so that's a bonus.

Rubber finger tensioner was tensioning air - so chain and chain tensioner are in order.  The flywheel was incorrectly indexed to the crank for some reason, so that's going to need some additional investigation when it comes time to time-everything-up again.

So, let's pull the cylinders off and see what we're dealing with.  And,  whelp, I'd already budgeted to change the cylinders and pistons out, so this isn't a shocker - but chrome has left the building.

[cmice]

Ok - today's update.  Made a rear main bearing puller - worked like a charm.  Here, again, mixed news.  First, the crank looks great so that's a relief.  The rear main bearing looks "ok" and I would probably run this, but curious what others think.  Unfortunately, front main doesn't look as good and I think he's a goner.  Again, what do calibrated eyes think here?

[Antietam Classic Cycle]

"Looks" are one thing, the micrometer tells the tale...

[cmice]

Ok boys and girls, always remember to clean out your crank.





A sort of rubberized slug of chrome dust and who knows what else came out - almost in one piece, but it broke apart into lots of chunks when I tried to extract it.

The bung plug was in only finger-tight, despite being "staked" and came out with only a faintest hint of thread damage (just at the very top where the stakes are). So he's going back in, but sealed and sent home properly this time.

[Antietam Classic Cycle]

This is from a '71 Ambassador with 98k miles on it.