GeraldRosebery

My Feedback: (14)

I have a relatively new (1 gallon gas) ZDZ40. It is turning a 20x8 prop using fresh 93 octane gasoline mixed 32:1 with Pennsoil. Although it starts and runs sort of OK, it is quirky. It idles at 1200 and peaks at 6950 rpm. All the throttle response is in the lower half. It reaches 6900 rpm at about 1/2 throttle and then gives no more than 50 rpm more at full throttle (???) The Low End needle is fairly responsive but the High End needle can be turned 1/4 turn either side of what appears to be peak rpm with little effect on the top end. There is a mid-range burble that cannot be eliminated. If I get it to go away with Low End mixture adjustment, the engine will quit on fast throttle opening showing it to be leaned too much. Comments?? Thanks to all.

krayzc-RCU

My Feedback: (31)

if your radio have a 4-6 point mix or a throttle mix now would a good time 2 use it[8D]

arobatx

Newer engine, propped to load lightly, keeping the CHT down a bit.

Plenty of oil, Lower CHT, lower load, rich condition, burble.

Let it break in, stay on the needles, and as suggested use a throttle curve. if peak is approx 7000....set your throttle stick at 1/2, and use your throttle curve function, and tach, to set half stick position at approximately half, 3500-4000 should do it. This will make the throttle feel linear throughout the stick movement. You can fine tune the curve to your liking and/or flying style as you progress. You might have better luck with a prop offering a bit more load on the engine after break in.

Chad