Hi i have an yamaha sr 125, the problem i have is that it doesn't like to go into second from first if i hold the gear lever up you can hear the gears tapping off each other and if i change back into first it is very very clunky unless im going at walking pace, i have recently changed the clutch and noticed cracking to the engine case inside only small spider web like fractures. I did a bit of internet searching and read that it could be down to a bent shifter fork but replacing it would mean splitting the block, i could do this myself but im not sure what i need to buy ie gaskets camshaft bearings, the other option i have is to buy a new engine for it.. second hand though but im not sure what will fit in it can anyone help?

Aye martin" go for the exchange motor, there plentyfull . its a major job,

pop up to the new members section , and post,

Before you buy a new engine , just check if your gearlever is tight on the shaft as a loose one can cause similar symptoms .

Before you buy a new engine , just check if your gearlever is tight on the shaft as a loose one can cause similar symptoms .

The splines had completely rounded off on mine - I ended up grinding a flat spot, tapping a thread through the lever and using a grub screw to hold it in place

I usually drill a small "keyway" , in between the shaft and the lever and use a nail as a key . Never slip again .

I'm not sure if i still class as a new member or not now as i have been a member since last december

I am definitely going to go for a new engine now but a few more problems have arisen since that post.. the cam chain guide has worn so badly sand has grooves in it and is causing the chain to sqew Into the cylinder which ithink is whats causeing the clunk/rattle noise when i hit the mid revs it got so bad it was backfireing so i rebuilt the top end to see what it was and thats what i found

Genuine yamaha cam chain slider: £75

New salvage engine: £100