rcagpilot83

When I throttle down to decend the engine starts to run rough and the tail starts waggin. It also does it when I land and throttle down, it like cuts in and out but doesn't stall. Noticed this problem when I switched from 15% fuel to 30% Byron fuel.

Goran619

My Feedback: (2)

You may need to retune your engine, I once used 20% and then switch to curtis oungblood 30%, if i remember correctly I had to lean out the engine because it is a stonger fuel and it will now be running rich.

rcagpilot83

I started to tune it lastnight but got dark out. I know the directions for the engine say that if your using a 5-30% synthetic heli fuel you should run it rich but perhaps i'm too rich. Another problem I had lastnight when I was trying to tune it was the one muffler mounting screw hole in the muffler stripped out so my muffler loosened up which would cause it to run lean. Taking care of that issue this morning and gonna try again to get it tuned.

Goran619

My Feedback: (2)

Yeah thats not a hard fix just use a longer screw for the muffler and then have it run through the hole and use a nut on the other end. Last year when I first got my raptor I was using rotorage 20% or something like that was using what my brother-in-law had, when I went to go buy my own fuel I couldn't find anything but 30% curtis youngblood fuel and thats what a LHS said I should be using in it was the 30%. When I first started using it the engine didn't run right, so I leaned it out since like I said it was a stronger fuel. If I remeber right I think I'm about 1/4 turn from factory on the high side and at factory on the low side needle but you will have to play with your needles to get the correct setting for your location. If you end up having to much difficulties I would recommend going back to the fatory settings on the needles and starting over.

rcagpilot83

I know the top end is 3 turns out for a starting point, but whats the factory setting for the bottom end mixture screw. Years ago when I flew planes for a .40 size engine I think it was like 1 1/2 turns out from closed.

BarracudaHockey

My Feedback: (11)

Sounds lean, how hot does it feel?

http://www.raptortechnique.com has two great articles on engine tuning.

Sigma.40

My Feedback: (1)

Mine was doing the same thing yesterday, but I found that the clamp to pinch the fuel line closed after you fuel it had popped open so half the fuel was leaking out and the engine wasn't getting very much. Irritated that I lost half a tank but VERY relieved that it was something that simple.

rcagpilot83

It was lean, got it running good now