Changing Oil

Sidjam

Member
I did find some pieces that have a right angle to them upon further inspection. So maybe not gasket then. Motor did run and go into gear. Any easy way to check cam chain idler wheel?
 

69ST

Well-Known Member
There are pockets hidden beneath the oil spinner gasket. This is what usually awaits. BTW...I agree, it's not bad. May as well be thorough. At this stage, the cleaning is easy.
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69ST

Well-Known Member
I think kirrbby nailed it, the timing chain roller has been chewed to bits. Since it's polymer material, it hasn't scarred anything. And the absence of metallic particles would indicate that there wasn't enough timing chain whip to allow contact with the cylinder tunnel.

At this stage, I'd pull the stator assembly for a better look inside. You may be able to just remove the round cam cover and poke a finger into the cylinder tunnel; probably won't be able to really see it. I'm guessing that the tensioner piston cap, which is also polymer, is crunchy by now. There's also a plastic idler sprocket on the chain tensioner arm. If this were mine, I'd replace the roller, tensioner piston cap, idler sprocket and throw a new timing chain at it...peace-of-mind for an extra $18. While the stator is off and before you start ordering parts, inspect the oil pump drive sprocket. If the teeth look like new, you're good-to-go. If they're worn, replace that sprocket too...and inspect the oil pump internals. Worn oil pump sprocket teeth almost always indicate a binding oil pump.

FWIW, it's usually easier to R&R the timing chain roller from the bottom of the cylinder tunnel. Remove the tension arm, then the chain can be fished upward, into place, the roller going along (part way) for the ride.

BTW, if you lightly oil the new oil spinner cover gasket on the side that contacts the clutch face, leaving it clean & dry on the flange side, it will stick to the flange and release from the clutch next time you go the clean the oil spinner. You should be able to reuse it indefinitely thereafter.

One odd thing I noticed is that someone replaced the JIS screws with slotted heads. I've never seen M6 screws like this before.
 

Sidjam

Member
Found evidence that the timing chain had previously ate into the case. I wonder if someone replaced the roller and didn't bother to clean out the pieces?
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cjpayne

Well-Known Member
I’m thinking they might have replaced tension gear with a used one?
I kinda doubt it, but anythings possible. Judging from your pics, looks like someone got into the clutch to fix or replace. While at it, they made a huge gasket mess and didnt bother to clean things up. When they stripped the spinner cover screw heads(very common), they replaced them with screws they had on hand from who knows what. I hope they used the same type threads. From the looks of the oil screen, I would think this engine was somewhat starving for oil. I would check the cam bearing journals for scoring and condition of the cam gear and cam itself.
 

kirrbby

Well-Known Member
I’m thinking they might have replaced tension gear with a used one?
Look back at post #18.
Part #13...that's what I think was shreaded. Maybe it's been replaced since, but you'll want to find out.
That drive gear looks pretty worn to me too.

The short story...this motor really needs a close look. It's been well used...maybe some abuse..?
But if you're just planning to get it running, and go from there...you need the cam chain to at least be able to run without causing damage.
 

69ST

Well-Known Member
The oil pump drive sprocket teeth are worn past the point where I'd replace the sprocket. I'd also inspect the oil pump; it may be alright. What I see are the results of excessive chain whip. Your pics are very good(y)

I'd still be surprised if the rubber roller, inside the cylinder tunnel, is intact. Regardless, I strongly recommend throwing a new chain, roller, idler, oil pump sprocket and tensioner piston cap at this. This cam drive assembly is used-up and will cause needless problems in short order.
 

Sidjam

Member
Ok, thanks. I'll replace all the cam drive components then. I'm working on this bike for my uncle and not charging anything for labor so just hoping to get it running good for his grandkids.
 

Sidjam

Member
I'm definitely a novice when working on these motors so I might need to lean on you guys to get this done. So to remove the oil pump drive sprocket I'll need to remove the oil pump correct? Also, where's the best place to source these parts? I was looking for a kit and the only one I've found so far is on CHP for $55
 
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cjpayne

Well-Known Member
Use OEM parts whenever possible. China parts just dont last has been my experience. Yes you will need to remove the oil pump.
 

Sidjam

Member
So I got the chain, roller, and idler out. Haven’t started on the oil pump sprocket yet. I removed the spring on the tensioner. Isn’t the tension piston supposed to move freely after removing the spring? Right now it seems stuck.
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kirrbby

Well-Known Member
Look just below the rod, on the outside of the engine case, there will be a slotted stud and jamb nut. Loosen the nut, and then the stud, then the rod should come out. There should also be ANOTHER spring in there.
 

Sidjam

Member
Ok, got the other spring out. This is what I’ve took out and the piston still isn’t moving.
 

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