TE/TC Fast Idle After Spark Plug Internals Broke Loose

My CR 144 blew a plug and now with a new plug fitted it idles really fast after blipping the throttle and gradually slows down but still too fast rpm. The air screw has little affect really. Took the carb to bits and seemed fine, reeds seem fine, new plugs and still no different. Any suggestions anyone? thanks.

since removed head and barrel and all visibly good. quite a bit of dark oil around power valves under cover but I assume this is normal? help please...

The debris from the broken plug did probably damage the crankshaft seals and you are sucking air in, or if the pieces were bigger even a cracked crankcase is possible I suppose. I would inspect the casings and do a leak test.

Air leak.

Paw Paw

When actually riding the power does not seem to have suffered at all, would the leaking crack seal not have a baring on this? thanks.

New piston and ring / gaskets and sonic carb clean, still fast idle, any ideas? was told by big 2 stroke tuner that the chance of anything getting through to crank seal is very very slim, especially if No marking is present on head, piston or barrel...

Hi, thanks for the reply. How is best to pressure test?

Turns out pressure has popped out the LH crank seal behind flywheel. Happy days! Easy fix