Rattling noise when leans left

[pinkslips]

Great site you have here.I've learned alot reading the posts here as a visitor. I picked up a 1970 ct70. Starts right up,idles good,runs good,shifts fine,top speed 42. The only problem I have is that when it is ideling and I lean it to the left(while sitting on it) there is a rattling noise coming from the engine.the more I lean it the louder it gets. It also increases with rpm's.Has anyone had this happen before? Could it be the timing chain? Thanks

 

[k1ct70]

Are you certain it is engine noise? I know my CT has a rattle from the front brake cable/speedo cable guide on the front fender. Noticable when idling and just off idle. I would check that first before performing open heart surgery on the engine!

 

[pinkslips]

Thanks for the reply but I'm sure it's coming from the engine or tranny. It's a loud rattling noise like metal to metal but only when leaned left. Straight up and leaned right it's fine.

 

[Flash]

I'd start by removing the flywheel cover and see it anything is amiss there. Looks for signs of wear/rubbing/loose parts or foreign material.

 

[pinkslips]

Thanks for the reply Flash. Sounds like a good place to start. If no one replies that had this happen to them with a solution then I guess I'll have to break out the hand impact driver.

 

[steampick]

I would also definitely check your timing chain and sprocket. A loose, worn chain will rattle quite loudly, even moreso if you tip it left where it could rattle against the head and cylinder.

 

[Miniac]

You didn't say if it is a consistent (rhythmic?) clatter or a completely random racket. If it's really consistent I'd think it's somewhere in the neighborhood of the clutch, or the aforementioned timing chain. If you need some help digging into things, let us know.

-kevin

 

[pinkslips]

Well I removed the flywheel cover today and found the source of the noise but I'm not sure how to fix it.The noise is coming from the shift drum assembly because I poped the rubber plug of the shift drum nut and as you leaned the bike left or right while it is running you can see the nut moving back and forth in rythem with the noise.Also by putting your finger on it and leaning it running you can feel it in sync with the noise. I made sure the nut was tight and tried it again but the same problem.It doesn't do it while in gear.Could this be something to do with the clutch adjustment? What about the star on the other side?

 

[XSIVE]

Is this a 4 speed Manual or a 3 speed automatic?

 

[pinkslips]

3 speed auto

 

[steampick]

Well, you can check the clutch while you're getting to the shift star, but the clutch shouldn't have much to do with that bolt. I have seen the shift star come loose before. Did you say if you were having trouble shifting?

 

[pinkslips]

Shifts fine, and kick starter doesn't slip.I thought if the star nut was loose it would have problems shifting.

 

[steampick]

Yeah, it usually would have trouble shifting.

You'll probably have to get into the engine a bit to find out for sure, and to really access that bolt, the engine halves will need to be split I believe. You could, though, just pop the RH cover and inspect the shift star without doing that. You will need to remove the clutch and primary gear, though.

 

[69ST]

The shift drum shaft should move freely, otherwise the trans wouldn't shift. The fixing bolt is there to limit endplay. Sounds like it's either a transmission or primary issue. The tranny mainshaft spins even in neutral. So, it's either not completing the gearchange into neutral or it's in the primary drive. A worn clutch pilot bushing, something worn/bent in the clutch or even a chipped tooth on the primary drive could be the culprit. There are other possibilities, as well. As luck sometimes goes, you don't have to split the cases to check the primary drive and shift linkage, just pull the clutch cover. If something is amiss, it should be easy enough to see. If not, you may have worn shift forks, pins or the drum; there could also be excessive endplay in the shift drum assembly.

One quick check would be to remove the chain, fire up the engine and see if the noise is present in gear. If it is, especially in all gears, then the primary drive looks even more promising as the source.

 

[Art]

Mine was rattling at a cruise, rattling went away when I leaned the bike to the left or right, forgot which side.
Turned out, the timing chain needed adjusting.

HERE

 

[chuckklr04]

Check your motor mounts first. weight transfer may be causing it.

 

[pinkslips]

Well before taking the clutch cover off I took the bolt out, behind the rubber plug ,holding the shift drum and added a thin washer behind theoriginal washer to take up some of the end play in the drumwhile still leaving enough end play so the drum was free to turn and the noise is gone.Does this make any sense?Still shifts through the gears fine while ideling but it's to late to ride here tonight so I'll run through the gears at speed tomorrow.Racerx any thoughts on it. Thanks