[Adam]

Guys I have an engine issue and would like some feed back. About a year ago I found when in level flight and starting a decent ( reducing manifold pressure ) about 3 or 4 seconds later the engine will run rough for 2 to 3 sec. I've checked fuel injectors, plugs, mags. It does not happen all the time and sometimes it maybe many hours between occurring.

 

[RV10inOz]

Induction leak!

Fuel control unit needs a service, clean all the goo out of the diaphragm.

Do you have an EMS data file we can look at?

Need a lot more info to diagnose than that.

DB

 

[aerhed]

If you have a counterweighted crank, you may be detuning the counterweights.

 

[Adam]

Thanks DB, I will check the items you indicated and I'm checking the EMS file as we speak. I'll let you know what I find from the EMS.

 

[Tom Martin]

It could also be a sticking valve. This used to happen on a friends RV6 when he reduced power and started a descent. I am guessing the change in temperature is enough to make a tight valve stick a bit. Talk to your mechanic about cleaning the guides.