82 400 seca. Bad tranny?

I've got a strange clunking noise. having trouble pinpointing exact location but i've determined that it only happens in first, and only under load. I'm guessing tranny...
This bike has been sitting for over 10 years. Is there anything else it could be? I'd hate to have to crack the case just to find out it was something stupid and simple.
Chain looks good. no stiff links.


Thanks in advance.
k

 

Could be a number of things other than stiff links in the chain. With a bike that's been sitting for that long there are a number of possibilities. We're going to need more info: miles on the bike; its history (if known) before you got it; what have you done (or not) so far; etc.

 

When do you hear it? Dropping into gear, coming out of gear, when you start rolling, occasionally when you are moving?

 

Sorry. wanted to keep it to the point.
Mileage is low. Not sure exactly but under 5k for sure (can check when i get home).
History is unknown. got it from some guy's brother. Never actually talked to the owner.
So far i've not done much with this one. cleaned carbs, changed oil. brazed and sealed the tank (por15).
The noise is constant in first gear. Goes away in second. have not had it past third yet.
If i put it on the center stand and drop into first it sounds ok. light pressure on rear brake and i get klunk klunk klunk. sounds like a link skipping (broken tooth style) but front and rear cogs are in great shape, as well as the chain.

 

I wonder if the internal Hi-Vo primary chain is the one that's developed a "stiff spot." In these bikes I believe it actually drives the transmission like on the 550's making it a TRUE primary chain; if the bike sat that long it's possible the portion of the chain that wasn't submerged in oil has rusted. I would put some gentle miles on it and see if it begins to lessen.

 

+1 on the gentle riding and miles.

 

Thanks guys. I'll give that a try and let you know how it works out.
I'm reluctant to ride it too much. There are a few other things i was planning to do to this one but that's all on hold until i find out what's up with the tranny.

If it was the primary, would it go away when i hit second?
Are there any oil additives that might help?

Thanks again.
k

 

No, there are two other things you need to attend to RIGHT AWAY.

Those are ten-year old tires. Replace them or don't ride it; the tranny will get resolved one way or the other. If it didn't have this problem before it was parked, it's most likely caused by sitting for 10 years. You could also have some rust in the tranny itself, on HALF of some parts and not the other half. Likewise the clutch. Those should clear up with some gentle miles and two or three "short" oil changes as it breaks loose and gets flushed out. But don't ride around on ten-year old tubeless tires.

Pull the rear axle and check the rear brake. Shoe delamination is WAY TOO COMMON on these bikes, especially after sitting long term. If the shoes are delaminating they very possibly could suddenly separate and cause immediate rear wheel lockup. Do this. It's not a case of being "overly careful" it's happened to too many of us. One member did have a lockup as result, luckily he wasn't going too fast.

 

Thanks again for the great advice.
I was skeptical of the tires myself, but gave them a serious look and decided to risk it. no dryrot at all and have been holding air since i got it. probably not too smart and would not recommend to anyone else.
I did not think of the break delam issue. glad i only went around the block (30 mph max). my neighbors must think i've lost it. "look, there he goes again."
I did put on full gear. Always a good idea on a first ride.
So, i'm reluctant to pick up new tires if this turns out to be a serious issue.
Anyone care to guess what it'll cost me if it turns out to be something serious? How likely will it be that i'll be able to get parts?

Thanks again.
k

 

Very likely on parts. If chacal doesn't have it here, EBAY is loaded.

 

Here's an update.
Replaced tires and put 50 very gentle miles on.
once out of first, this thing runs great.
in first, klack klack klack.
it's pretty quiet if i'm maintaining speed. it's loud if i accelerate or decelerate.
sounds like someone tapping a wrench on the side of the case.

How many miles should i put on before i give up and look in the tranny?
and
Since it looks like the only way to get in there is to start at the valve covers, Is there a comprehensive list of parts to order (gaskets and whatnots/whosits) somewhere that anyone would care to point out?

thanks again
k