Hi All , need abit of help, 2011 sherco 290 started to knock for no reason replaced main , big end bearings con rod small end and pin, piston and barrel where perfect, but engine still knocking, puzzled, any ideas would be great. Thanks

Check the bolt on the flywheel.

Thanks for the reply, checked flywheel nut, stator, clutch, every nut and bolt tight, even put the piston and barrel from a 2013 bike on , no joy still knockin, Its astrange one.

Clutch rattle? does it change sound when clutch is pulled in.

It is possible for a big end to knock and yet be very difficult to find any play in.

Is it only when you get off the throttle? If it's getting cooler where you are it may be time to richen up the fuel screw.

Not clutch rattle, bigend bearing was replaced, could a new bearing be faulty??

The knocking is from start up and builds with the revs.

Have a look for damaged teeth on the kickstart idle gear and gear on clutch drum this engages with, this caused a knock a Gas Gas I had

Had that on a gasgas aswell, was one of the first things i checked, thanks for that.

Well, from what you have stated it is not the top end, the bottom end or the gears, so it must be fine!

Let us see and hear a vid ofit! It is difficult to diagnose noises or the tinternet. My crystal ball sucks!

You state replacing big end bearing? Possibly so, however last time I checked, thece come in a conrod kit with a new rod and crankpin. You know, the other mating wear parts there upon a true lower end knock. What is your clearance Clarence?

There are only so many rotating parts there, you know!

Is the he crank running true after fitting big end Had one on a Villiers motor went out of true when tightening the sprocket and flywheel and twisted the shaft by a few thou

Thanks Copemech, Naichuff,Melba26, Heffergm, Dadof2 and last but not least Thats a five for all of your input , Melba26 you where close , it turned out to be the clutch rubbers, never thought they would cause such a knocking noise, lesson learned, thanks again for your help.

Didn't consider the clutch rubbers & I replaced mine last year, it's amazing how much quieter the motor runs afterwards & is a cheap easy job to do

I've heard a clutch with the rubbers gone before, this was a different noise altogether, thats why it took so long to find the problem, but atleast it sorted now.