my rev3 270 has suddenly started ticking over realy fast. when i turn tickover screw out to slow it down it stalls. i have cleaned carb and filter and checked airbox and throtle cable has freeplay also checked the timing hadnt moved but all seems fine. any advice would be great

Sounds like an air leak. I have three suggestions for things to try.

Squirt some soapy water around where the ignition wires enter while the bike is turning over. If you have a main seal leak on that side you'll see bubbles as the crankcase presurizes.

If that doesn't do it try the same trick around the reed block area. On mine I have to run a gasket with on both sides of the reed cage (there is normally not one on the manifold side) and use sealant or I have air leaks.

Check for chipped, frayed, or reeds that don't close.

Hope this helps

Joe

Sounds like a leak to me .

Edited September 29, 200916 yr by betabonkers

thanks for that joe. i have just checked my reeds and there is a gap of about a mm where they are not shutting i gues this could well be the problem. think il order a set of boysen reeds. thanks again

No sweat, glad to help, you're gonna love the reeds anyway. In mine they made the bike much more forgiving of mistakes (and lord knows in my case that's a great idea).

Once you have the manifold on and before you attach the carb take your thinnest feeler gauge and see if you can slide it between the manifold and the reed block. On mine I could get a .002 (not sure how many stones that is ) between the two and it was just enough to cause all sorts of wierdness.

Have fun

Joe

You could also check the air screw someone may have turned it lean without your knowing. Also some grit may have lodged itself in the pilot jet.

What a plonker he put his piston in the wrong way around when he changed small end. ticking over like a dream now.

Edited October 3, 200916 yr by betabonkers