Yamaha TRX850 Enthusiasts Forum

Not sure if this is just a normal thing the TRX does, but it now (dont think it did it before) seem to be getting a bit of an unusual, but even so slight, noise that I feel through my feet after I let the throttle off. Engine pulls well and has never missed a beat, but you know when something just seems a little different..... or is it me being paranoid !!!!!

Heavy noise? Chattery noise? Other noise..?

Tis like a knocking feeling more than anything else. Certainly not loud, quite hard to describe.....

Probably best to check the easy things first, like chain and sprockets - are the sprockets hooked? Does the chain have tight spots? They can work perfectly in the normal driving direction but not be very happy in the other direction, particularly hooked sprockets.

Don't know if i am being thick, what's a hooked sprocket? If i think you mean worn sprocket, then no they are brand new had then fitted about 250miles ago, and same for chain. Chain has about 20mm ish movement, but as fir tight spots not sure. Am quite new ti this sort of thing so do excuse my ignorance.....

Yes a worn sprocket - as the driving side of the teeth gets worn away the teeth turn into hooks.

Is that 20mm of movement when the bike is on its stand or when you are sat on it? If it is on the stand then it might be too tight, a tight chain can really grumble away. Your rear wheel might also not be quite straight, which can wear the teeth of the rear sprocket against the sides of the chain and cause some awful noises.

My money, as you may suspect, is on the chain making the noise

Cheers, i'll have a look at that asap and check the wheel alignment

Just chech if there is any play in your cush drive on the rear hub when looking at the back wheel too.

Head bearings?
Just have a general check that all is tight: axle nuts, brake caliper bolts, head bearings. Then check for anything attaching on anything else.

The sprockets maybe slightly misaligned. I did a 520 conversion once and had a similar issue. Solved it by spacing the sprocket.

Check your engine mounting bolts.

Mr Snod Blatter, think you might have been right on the money. Got the wife to sit on the bike on the paddock stand an was amazed at how much it tightens the chain up. So loosened up the chain to 25mm, checked the wheel is in line and hey presto

just to be on the safe side, checked head, cush drive, engine mounts etc thanks to all for the help