1981 R65 Harsh Knocking

[matthewjp14]

Pics attached.

Went to the hardware store today anyways so I decided to get the parts to make that puller. Less expensive than the hardware I was buying to bolt my garage sale find mini vice to the bench.

Went with a 2 inch floor flange, mated to a 2 inch to 1 inch coupler, with a 1 inch plug to cap it off. I'll drill the hole and thread in a stud or puller bolt or whatever I've already got lying around to make it work later today.

Considering this will officially be undergoing a rebuild if it is timing related ill update what happens here but start a new thread for that kind of thing.

 

[matthewjp14]

Happy to report; fairly confident in the notion we were dealing with timing chain tensioners. I'm not really familiar with these systems since this is the first time I've seen inside in person but I'm pretty sure there was supposed to be a lot more meat on the tensioner arm specifically. On the rail side there was about 3-4mm of play. Pic for reference. Both had been pretty chewed up and it looked like something that would probably continue if I don't address that now.

Wondering what people's opinions are on the spring tensioner here. It looks good to me, engine has roughly 30k miles on it so if that will get me to 130 I will be leaving it alone for now. Bearing spun fine as well no rough patches of any kind, no play and no slippage. on the shaft.

Parts list is gonna include chain, rail, tensioner arm, front main seal, gasket, and circular gaskets for the upper front cover bolts. Combined with new spark plugs and wires (much needed) I think we're gonna have a runner for sure. I'll start that thread when I get everything in. 

[Bob_Roller]

Something I just remembered, there are openings in the engine case, they are for oil return to the oil pan .
Plug those openings with a rag or paper towels .
Things can fall into them and end up in the pan .
Experience here !! 
Just remember to remove them before putting the cover on .

[dogshome]

A lot of wear on the tensioner and chain for sure (plus some slightly spikey teeth on one of the sprockets) it's visibly beyond 'ready' and only 30K miles???  But 'sudden deafening etc etc' doesn't make me think of timing chain. A gradual increase in ticking, rattling, clanking or clicking noise over a period of time. 

Why has it gone? what else has....


You did check the big end didn't you?


Hoping I am utterly wrong and the chain was banging to be let out.

[matthewjp14]

I did check the big end on the noisy side, all is in spec. Good compression, good rings, no scoring or markings or metal anywhere. I still have to take the other side off because I already opened the first one and might as well do both head gaskets while I've got it apart.

The only reason I'm allowing the chain knocking to be a potentially sudden thing is this front case had not been opened for 20+ years and sat in someones garage. I then put that 30k motor in my 150k+ bike and have ridden it as a man in his early 20's would for about the last year. The only seals I didn't change when I took it apart were the front seals and timing components bc well, it was in time and didn't leak too much oil. I want to assume the plastic got brittle through the heat and age and can and will chip and break off and get thin really quickly.

That being said it could still be entirely the wrong diagnosis here but that amount of free play in the timing chain would create a significant amount of noise no? I would consider the noise I previously heard to be clanky, ticky, rattly, knocky, all of the above; especially when off idle when there's going to be more speed and more slap in that timing chain.

[matthewjp14]

You did check the big end didn't you?

Hoping I am utterly wrong and the chain was banging to be let out.

Hey, about that timing chain. Finished working it up in June and had to move and started a new job so it has actually sat unridden for several months now. It did make the drive from old place to new so I'm not sure where to go from after replacing the entire timing chain and tensioners.

The sound has not changed in intensity or speed. Remains exactly the same.

I've done more forum post digging and come to a few conclusions and possible next steps. First would be checking if my clutch is out of adjustment. The noise doesn't change when I pull it in but some riders have mentioned a similar noise from old weary clutches which i definitely have one of. Second would be bent pushrods, I would imagine a bent pushrod would send me some wild information in a compression test but it is totally possible a pushrod bent and wants to make a ton of noise. Third would be piston slap, I guess it's technically possible. There was no sign of this when I last opened it up, pistons moved smoothly on the rods, but maybe theyve frozen up between then and now. Fourth would be connecting rods; at the end of the day I don't want to do connecting rod bearings but I would much rather do that than timing chain again. I'm willing to pull those out and see what's happening before the rainy season starts here.

For anyone seeing this thread for the first time, the noise is on the right cylinder. I was convinced it was timing but not the case. I am susceptible to being told to open the conrods if someone had a convincing argument in favor of it.

Also have a much better video of replicating the noise if anyone wants to hear/see it in action. I my post on youtube and link here if there's not an easy way to upload a video to this site.