Minch

I have a ZDZ 60 blueline which has developed idling problems, it won't idle below 2000rpm. I have had a few problems with it recently and am hoping someone can help. I was flying it a few weeks back and the headbolts came loose in flight and the engine stopped, I re-tightened the bolts but couldn't then get her to idle properly, I noticed that fuel seemed to be leaking out of the cylinder gasket and I thought that air may be getting in aswell. I purchased a new cylinder gasket last week which I have changed and engine is now leak free, I also fitted a new spark plug which had the gap checked and adjusted. I spent about 3 hrs sunday afternoon trying to get her to idle but no luck, she will peak out at full throttle, about 6400 rpm (24x8 prop and a JMB muffler) and the throttling from 2000 rpm to max is excellent. I have tried resetting carb low and high to factory and re-tuning but she still won't idle below 2000 rpm, she just peters out and stops.
When she stops she will not restart immediately, but if the plug is removed, then replaced untouched she will then restart.

I have also done a bit of research on the internet and a common idle problem seems to be that the throttle butterfly can be fitted backwards or if the carb is removed the butterfly can be incorrectly refitted, I checked on my engine and the butterfly appears to be working in the correct direction, the carb has never been removed. The engine has had aproaching 5 gallons of fuel throught it now and until recently it was running and idling ok.

Can anybody give me any ideas of something else to try??

Also tried:

New Fuel
New Ignition Battery
Re Timing engine - But sensor was in correct place.
New Plug.

Thanks In Advance

Nick

Mike Dooley/RCS

Nick,
Do not run it anymore! You have an airleak causing it to run lean. That is bad.
Box it up and send it in for us to fix properly for you.
Thanks,

Minch

Mike,

Thanks for you reply, as I am in the UK and if you think its that serious I will get in touch with the UK ZDZ dealer where I purchased the engine. I think the engine is still be under warranty as I bought it in Jan 2005 and according to ZDZ's website they have a 42 month warranty.

Thanks

Nick