1982 XT200 bearing noise?

[scottieh]

My girlfriend recently bought and got running a 1982 XT200. The engine unfortunately makes a not so good sound near the right case half and it sounds like a bad bearing. I’d love to hear what you think.

https://youtu.be/Wmz57Mh8PT8

[Team_Yamaha50]

Sounds like something is either worn out or grinding with another part on/behind the primary gear. The best bet would be starting from the simple things by taking the clutch cover off and have a thorough inspection on each part until you find the issue.

[Mezo]

Make any difference with the clutch pulled in? and any if in gear?

Mezo.

[scottieh]

Took the side cover off with much resistance from the shitty phillips head bolts only to reveal no serious wear and tear. One of the teeth of the kick start gear had a small chip in it and the oil filter had aluminum shavings in it but the drain bolt did not deposit any. None of the bearings looked wrecked and the shafts didn’t have any play in them and didn’t make an obvious grinding noise or feel when turned. Where could the aluminum come from?

Gonna reassemble and start it up again and listen for any changes with clutch in and out and while shifting through gears. Fingers crossed this doesn’t become a beginners’ lesson in how to split an engine.

[charliext1vj]

Cam chain guide failure - or cam has picked up?

[Mezo]

cam has picked up?

Or the back of the piston?

Mezo.

[motorang]

Dunno that specific engine but Yamaha has a record for the primary drive nut coming loose.
The noise sounds exactly so.

Would suggest to thoroughly check that.
They uprated the torque specs for those nuts in the end 1980s, e.g XT600 from 70 to 90 Nm.

Andy

[scottieh]

Update:

The primary nut, counterweight nut, and clutch nut torque specs were all fine. Sharah retorqued them anyways but it was unnecessary.

We did discover however that the kickstart mechanism was a bit funky. When fully reassembled the kick lever mechanism would only engage very close to the bottom of the down kick. Only about 1 out of 6 times would it catch at the top and allow for a full kick.

Digging back into the case we realized that the spring and helical splines of the shaft and gear did not engage with every turn of the shaft. It was also noticeable that the kick starter gears and the starter idler gear were not meshing correctly and that they each had damage to their teeth.

The aluminum shavings we found were quite possibly from the kickstarter grinding inside its seat and from the spring grinding against the case interior on each kick rotation.

I'm still unsure if this will resolve the other rotational whining noise while the engine is running, but it's a start.

So, it was off the ebay races. However Ebay sellers wanted an outrageous $350.00 USD for just the kick start mechanism and lever! When asked about their high prices the seller claimed that new TW200 bikes don't come with kick starters installed and the owners are willing to spend the money to retrofit their bikes with these old kickers.

And that's how we ended up at a junkyard.



There's a somewhat well know known motorcycle boneyard here in Salt Lake City called Bill's Boneyard that is the most massive, sprawling collection of Japanese motorcycle parts I've ever seen in my life.



Bill showed us around his property and pointed out the likely places where we could find an XT200 motor. Outside are three or four piles of motors like this











Inside the deep, dark shop are shelves lined wall to wall, floor to ceiling with motors, tanks, plastics, fairings, and everything else motorcycle related.

During our second pass through the shop we finally found what we were looking for - a mostly complete, non-seized early 80's XT200 engine, with intact kickstart mechanism. Bill looked it over, spun the crank by hand, and suggested a retail price of $80 for the lump.

Sold.

[Mezo]

That`s a bloody disgrace letting all those parts just rust away

Mezo.

[scottieh]

Latest development is that the spare engine we picked up has a big hole in the case near the output shaft sprocket. Looks like a chain broke and cracked it good.

So our plan to swap engines is a bust. Original engine’s kicker mounting cast in the case is rounded out and now this junkyard engine also has a broken case. Bad luck all around.

Unless we can mix and match case halves then we have two bad engines and no more XT200’s within a few hundred miles.

Can you put two case halves together from two bikes? I think i know the answer.