RevMaster: rough on take off only

[flyingbear]

My Aerovee does EXACTLY what Mikes does- exactly. And the solution is the same- lean a bit (or advance throttle slowly). I lean my mixture at all times,even at idle after startup.

[pilotyoung]

My AeroVee does the same thing. As soon as I start it, I lean it aggressively and shut off the secondary ignition. That way at low engine power the secondary ignition is not drawing power. Then I put it full rich before I do the run up. Leaning aggressively is not my idea, I got it from another member on here. By leaning aggressively, if you forget to push the mixture to full rich, when you give it power for takeoff, the engine will miss.

[BRS]

My AeroVee does the same thing. As soon as I start it, I lean it aggressively

Thanks, ground leaning is already something I do, which I learned on certified aircraft. Seems these engines with their slide carb needs it more than the Lyc/Cont engines do.

The next thing I need to learn is how to best lean during low/idle power descents. I want to get to where I can fly base and final on idle but I'm afraid of the engine stopping. Had that happen while taxiing in once.

Does anyone with a Prince P-tip know what airspeed is required to keep the prop turning?

[Onex107]

I can't count the number of times I have heard the "mixture problems" at idle comments. I know you won't believe me but the #2 and #21/2 needles in the Aeroinjector both had that problem. After extensive testing and needle making, I found the #3 needle moves the idle sweet spot to where it is in the correct position with the slide valve closed, at idle. I never have had to adjust the mixture during or after landing and only adjust at cruise to raise the EGT temps to a leaner mix. With the two lower needles I had to lean during taxi or the engine would stop.

[BRS]

...I know you won't believe me but ...

I believe you. Hmmm wonder if Revmaster has a different profile metering-needle.

Thanks.

[BRS]

After months of wrestling with this Revmaster "RevFlow" carb I finally purchased an AeroInjector. After a few hours of adjusting it was ready to test fly. Bottom line - it works! Not balking, no hesitation, full 3200- static rpms. EGT's cool in flight.

Following are some pictures for the setup.

First off I needed to fabricate a cable reversal bell crank. I built it such that 3" pull on the control is 1.5" push on the aeroInjector. Sorry the pictures are so large, you'll have to click on them to see the full image.

BellCran_b4_install.jpg (196.24 KiB) Viewed 6111 times

BellCrank_Underside.jpg (117.77 KiB) Viewed 6111 times

The bellcrank base is made from 2" angle. The radius didn't quite fit the 1/2" Diameter engine mount tube but with some sanding it was not far off. Then the radius was liberally filled with RTV and loosely set in place to dry before tightening the hose clamps. The hose clamps are protected with Adel clamp rubber strips so as to not damage the mount.

With the engine off the control works smooth as butter but there is a bit of resistance felt when accelerating. Thinking this is normal as a sucking engine will pull that slide tight. It's not too much, just different.

Now onto the carb.....

[BRS]

The RevFlow carb is 35+mm which was replaced with the 32mm AeroInjector. 32mm works well. I noticed right away that the S flange almost fit into the Revmaster flared intake tube and that sizing was such that a rubber coupler would be problamatic. So I drilled and slit the end of the revmaster flared intake flange so that a hose clamp could be used on it. Next I turned down the S-flange by .020' which fit perfectly...

Flange_turned.jpg (215.33 KiB) Viewed 6105 times

From this angle these carbs look about the same in size. But the AeroInjector feels about half the weight of the RevFlow carb.

Both_Carbs_size.jpg (247.61 KiB) Viewed 6105 times

Here you can see where all that extra weight comes from.

Both_Carbs.jpg (249.27 KiB) Viewed 6105 times

The drilled hole and slit (under the first hose clamp) in the intake tube is covered completely by the S-flange. It was also sealed with a bit of RTV to boot. The second hose clamp is only for the safety wire attachment.

No doubt there will be more tuning to be done but so far the Revmaster seems to be running very well - finally.