1982 550 SECA crankshaft chain tightening???

Hello,

I have a 1982 SECA 550 with 31k miles on it...thing had sat for 3 years prior to me buying it...I changed the oil, cleaned the carbs and got it running again...but the thing has an odd harmonnic thrumming coming from the motor.

I thought that it was the camshaft chain so I adjusted that per my Clymer manual...while it helped a bit, the sound is still there. I was wondering if there is a main crankshaft chain, and if so, can it be adjusted...


Thanks,

Jon

 

There is a "primary chain" that runs off the center of the crank and turns the jackshaft that has the primary drive gear, starter, etc., geared to it. It has a large spring-loaded (?) tensioner that also appears to be oil-fed. None of this is accessable without splitting the crankcases, and not adjustable. When I got my '81, it was QUITE noisy from there, but now, 600+ miles after two oil changes and currently running 20W40 conventional oil, it sounds 99% better. Neither the Clymer nor factory shop manuals give much info on this thing; you will notice it quiet down a bit when you pull in the clutch. Can't use my '83 to compare, it has only 7000 miles on it and when I got it, it had a FULL GALLON of oil in it. Haven't gotten it running yet, myriad of issues (never buy even a very pretty bike off eBay.)

 

Thanks for the info...guess I am just going to finish my regular tune up bit with this bike and run it as if it were not making the noise...should be interesting to see what happens.


Thanks,

Jon

 

That's what I did and it's running fine...

 

Hi Vo primary chain ..They loosen up regularily. Similar is Used in Yama Sno machines on those it can be an annual repair item.
Expensive to buy and V labour intensive to replace. Generally a Sell the Bike Time signal IMO.