Hi Dave,

I have a DZ140 with low run time. It has been running faultlessly until recently. All of a sudden it has started to quit at idle either during spins or stall turns. I have replaced glow plug, fuel and all fuel lines.

The engine now wants to run about 1/4 richer than before. (Now at 2 turns) I have leaned of the pump which seems to cure the problem but I find the engine gets a little cranky during throttle transition to full throttle. In other words if I lean out the pump the motor wont quit but is too lean to run. If I richen the motor were it transitions nicely it will quit on idle. I have checked for leaks and reset tappets.

Using Coolpower LV with 25% nitro
OS F plug
16X12 APC


Regards,

Peter

Leaking piston ring maybe, but hard to say without seeing it.