Carb cleaner?!?
I'd use liquid wrench or some such that won't harm the piston ring/cyclinders
What is happening, my guess, is that the carbon build up is NOT at the tip, but
*ALL* along the extended nose barrel. That then crumbles as it comes along and
further binds
Recommend liquid wrench type, work it loose till it stops, turn it back
in 1/4 turn and then spray to soak a bit
Loosen till it stop again. Turn it in a 1/4 turn and spray.
This will soak the carbon and soften it so that it won't bind.
Repeat till they come out or bust...
Good luck !!!!!!!!!!!!!!!!!!
PS...soap box rant....WHEN ARE THE OEM'S going to hire engineers who
actually wrench their own vehicles???
