nander wrote:Teazer: The transmission shafts all spin freely and look to be ok. I don't know the age of the pistons. I had the motor rebuilt many years before I actually put the bike together and ran it. I remember getting new rings for the rebuild, but I think the guy who did it used the existing .25 over pistons.
Piston skirts: so some scoring is normal on used pistons? Can they be smoothed with 1000 grit and refitted or must they be replaced?
Valve clearance: The .004 feeler gauge was nowhere to be found at the time I loosened the adjuster. However, by hand I could tell that the cooked valve was noticeably tighter than the other three.
Starter clutch: The loose screw is backed out to the point where it must have been in contact with the sprocket. It looks like the sprocket prevented it from coming out completely. I'm not very familiar with this mechanism, but it would be right in line with my kinda luck for a single halfway backed out screw to bind up the whole motor. Is that possible?
Thanks,
nander
Reading valve color
Now see if ya can turn the starter sprocket by hand. (the one on the starter.) ......lm
What ever ya use I caution ya to not remove much if any of the metal. ...........lm
Light skirt scoring is fairly common. Alu migration onto the liners isn't. I'd be inclined to lightly buff the pistons' skirts with wire wool or, very carefully, with 1200-grit wet 'n' dry across the lines (i.e. around the skirt) a little; a scored skirt is better than piston slap. OK, so the trans is OK
One crank bearing needs replacement Pistons are OK as they are Bores are fine as they are Pistons may have been clean or may have had carbon on the crown when the motor was built - we have no way of knowing which. The stains in the bores come from sitting around for years - that's rust from condensation. One valve is overheated and should probably be replaced and the seat cleaned up. There is a loose screw in the starter clutch that should have been staked and that raises a few questions. Those screws are double staked IIRC at the factory, so is it possible that the starter clutch in some how or another grabbed the starter motor and caused it to rotate. That would create a lot of additional drag. That would be unusual, but anything is possible. I'd pull the rotor and inspect the starter clutch and while the chain is off, double check to see if the starter still works.
I asked that!
<<<Did the screw contact the starter sprocket. .................lm>>> <<<Now see if ya can turn the starter sprocket by hand. (the one on the starter.) No reply as yet. I've been aiming at that (noise) area if ya look back in the early messages. ......lm
Sorry for the delay. I didn't have the starter clutch close at hand. I went and checked it out this evening.
I confirmed that one of the starter clutch screws was backed out several millimeters, enough so that the countersunk head was fully exposed. As I looked at that loose screw (and before reading the last couple of posts) I saw the punch marks in the screw heads and wondered if they came like that from the factory? If I understand correctly, those marks are the staking you are referring to Teazer, and that they are to be expected? When I placed the sprocket back in the starter clutch I could see that it was forced into an off center rotation by the exposed screw. The sprocket still spun in one direction and locked in the opposite direction, which I assume is the normal way the little rollers provide a clutch action. However, I imagine it would have created a wobbling motion in that sprocket as it rotated. I didn't see any noticeable scoring indicating rubbing of that exposed screw on the sprocket as it spun. So, maybe it was held tight against the starter clutch but had an eccentric rotation? Is this what got all bound up and locked the crank? If so, I don't remember the starter chain looking screwed up or out of place when I took the thing apart. I'll inspect that chain again. And, what's the procedure for staking those screws back in place? nander
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