Throttle sticking

[boyd]

My bike has been running really well lately after a series of dramas, until today the throttle stuck open.
I took off the tank and had a look at the carburettor, the throttle body was jamming and not returning with the spring, I took it out and cleaned it up a bit with some steel wool as it had some marks on it and sprayed it with wd40. Now it is returning but not as snappy as it had been. It almost looked liked there was some heat damage, any ideas? Boyd

[iansoady]

Have the nuts holding it to the manifold been overtightened? This can distort the body. I've had some success with Monoblocs by squeezing the top part of the body in the vice to get it round again after some PO has overtightened them. The slide should fall out of the body when you turn it upside down but shouldn't rattle.

I always fit the carb with spring washers under the nuts and only tighten till they're just compressed.

[Les Howard]

I have had this happen, can't remember exactly what the cause was but do not forget to check the throttle cable. As you snap the throttle closed , the carb spring has has to be able to pull back the slack in the cable that you have just created...so check cable and lube thoroughly check for frayed strands too....ATB...Les