Cylinder EGT Question

[Seth]

I have an IO-550 in my Mooney Missile and I replaced the cylinders recently.  I'm about 25 hours into the break in, oil consumption is fantastic, temps have settled, and the plane has been running pretty smooth.

 

The last two starts however have been not as smooth - the engine has barked to life and vibrated more than I though in the past.  It settles down pretty quickly but is not as smooth as I thought I remembered.   Also, on short final, pretty much when touching down on my last two landings (one where I went for fuel yesterday and then when I landed at my home base) the EGT for cylinder #6 was low compared to the other cylinders.  The EDM 830 was actually blinking as the was a 300 degree temp differential.  This occured both on the landing where I was getting fuel and on my landing at my home base.  Once on the ground, i did a runup at both location and everything seemed fine.  In the air, everything seemed fine, on landing, the EGT is dropping off on #6. 

 

I even pulled out power to see if the engine would stumple or stop at low RPM on the ground, and it was fine.

 

Any thoughts or reason for concern?  Valve issues on a new cylinder?  I think, but it was a snapshot during short final, my EGT for the clinders awas 1000 to 1200 for the rest and 800-900 for #6.  Obviously hotter when in cruise.

 

Thank you in advance for your collective wisdom.

 

-Seth

[Awful_Charlie]

I would check your plugs on #6 first

[74657]

Check the plugs.  Mine would stumble really bad at low power settings unless we leaned it back.  We had to do that to get the fuel flows up high enough at takeoff.  I know another day or 2 of fine tuning would have eliminated the need to lean back but we were happy with how it flew and left it alone.  I'd rather have too much fuel in the pattern than not enough at takeoff.....

 

Plugs and check for too rich at low power and also your fuel pressure when it does that.  Mine ran really high for aforementioned reason up top.  The fuel pump on that engine has 3 adjustments.  Low/High/Idle.  If you adjust 1 the other 2 change.  It is a balancing act.....

 

Also look at your exhaust for cracks or burned out gaskets.  Get ready to bend over if you ever have to replace the muffler from Rocket!  I think they wanted 3500 or 4K.  We had ours "remanufactured" with a yellow tag by a shop in FL that reused one of the flanges which I guess was enough to call the part a reman.  With no cowl flaps there is a lot of heat in that engine and I don't care what Rocket says about how cool everything stays.  You have to know how to fly the plane to keep the engine happy.  I could climb at 1500 fpm in the winter time but a 90F day in June ~600-700 was all it would take even with 28 gph on takeoff.  The EDM 830 you have is the best investment you could make for your engine.

[N201MKTurbo]

You might check if the intake riser is loose.