OK, I'm trying to figure out what could cause this. I rode my 1988 Hurricane to work tonite. No problems. When I started it up to ride home, it fired right up without choke. After 90 seconds or so, it started knocking like mad. I turned it off and checked the fluids and looked for obvious problems. Nothing looked out of place. I started it again and looked while I listened. Nothing visible or obvious. I took my chances and rode around the parking lot a time or two. The knocking followed the engine speed. I stopped and shifted into neutral and revved it up a time to two, (just to see if anything would let loose), but to my surprise, the knock went away. When it came back down to idle, it was smooth as ever. So I leaned it over on the kickstand, and the knock came back. I determined that I could make the knock come and go by leaning the bike left (knock) and right (no knock). I was able to drive the bike home, 60 miles away, no overheating or oil pressure issues, bu I did notice the clutch is slipping under hard acceleration. Any ideas where to start looking?

 

I had a similar problem with an old CB750 once, knocked at low revs (even straight up)
Turned out to be the clutch basket, which is rivetted on that model, and the rivets had worked loose over the years, causing it to knock. Pulling the clutch in doesn't help, but revs make the noise go away......(you can still run a bearing and have oil pressure-let's hope it's not that)[X(]

 

After some more testing, it also knocks in the straight up postition as well, but not quite as much. Is this a timebomb or just a nuisance? Can I ride it to the shop or should I put it on a trailer? If it is a loose rivit in the clutch basket, is the basket repairable or should it be replaced?

Thanx
Chris

 

I still have my old CB750, and I recently did 100 miles on it at freeway speeds, clatter and all.......it's not something I'd recommend, but if you're prepared to chance it......
I don't know if the Hurricane's basket is the same, so can't help with the repair side, sorry. The CB750 can be removed and re-rivetted, but as I ride the bike so seldom, I haven't bothered with it.

 

Shadow1, both of my CB750's rattled in nutral and cleared up with the cluch in. I cringe when I see someone drop the cluch. I had over 40,000 miles on mine before they went to rattling.

flyingeyepro, I would search the forum for how to adjust the balancer, or refere to the manual.
I would start there.

 

My old girl's done over 62000 miles now.
Good thinking on the balancer, TBT......could it be....?
If so excellent ! Easy fix.

 

Before you go rushing to the shop, use a large screwdriver and place it in the area of the clutch and place the other end to your ear. This will determine the area as to were the knocking noise is coming from and also if something is loose or is just rubbing.