I collected my fx750 Genesis (1990) on Friday, and have now ridden about 500 miles. It seemed a bit rattly when I first got it, but this has gradually got worse. It is speed related, not engine revs related. The drive chain needs tightening slightly, but is basically OK, and I'm happy to do that.

However, moving the drive chain slightly generates a small rattle somewhere behind the small sprocket cover.

Therefore, based on other reading, I reckon the problem is the primary chain. Unfortunately, the bike didn't come with a manual (have ordered one), and this is my first bike with a primary chain arrangement, so I don't really know where to start.

Can someone describe, in simple steps, how to change the oil and adjust the primary chain? How can I tell whether it needs replacing?

Thanks.

I thought primary chains went out with the arc, remins me of my tiger cub days? Cant see the point of them unless its somehow a retro look thing

there is no primary chain in there to rattle. it must be something else. could it be gearbox sprocket?

hmmm, ok, I guess that could be good news....or not.

I haven't managed to get hold of a workshop manual yet, so I'm working a bit in the dark. I found a few suggestions about primary chains, and also found one for sale here: motorcycleproducts.co.uk part number 409250. The picture seems to be of a double width chain rather than a normal final drive chain, so putting all that together I assumed there to be a chain internally.

However, if that's not the case, guess I need to delve a bit further.

Rattle has been greatly reduced by adjusting the final drive chain, but is still there. It seems worst when doing about 30mph in 4th. I think that's because there isn't a huge amount of drive going through the chain, yet it's quiet enough to hear clearly.

Any other suggestions anyone? Thanks.

Any other suggestions anyone? Thanks.

Get a noisy exhaust and you'll never hear the rattle?

Get a noisy exhaust and you'll never hear the rattle?

hehe - already has one, it's just the rattle is louder at 30mph. I guess the answer is to either ride at more than 30mph, or always do it in first ...

hmmm, ok, I guess that could be good news....or not.

I haven't managed to get hold of a workshop manual yet, so I'm working a bit in the dark. I found a few suggestions about primary chains, and also found one for sale here: motorcycleproducts.co.uk part number 409250. The picture seems to be of a double width chain rather than a normal final drive chain, so putting all that together I assumed there to be a chain internally.

However, if that's not the case, guess I need to delve a bit further.

Rattle has been greatly reduced by adjusting the final drive chain, but is still there. It seems worst when doing about 30mph in 4th. I think that's because there isn't a huge amount of drive going through the chain, yet it's quiet enough to hear clearly.

Any other suggestions anyone? Thanks.

Maybe the chain you saw was a cam chain, Dont know the bike but possible, They are still used.

Go to the rear sprocket and at the furthest point at the rear of the sprocket, try to pull back the chain from the sprocket, There shouldnt be much movement here, If there is youre looking at new chain and sprockets to fix!