LynnR

My Feedback: (4)

Have a G-90 with a Magnum 91-108 carb on it. The high speed needle seems to work best at about 1/2 turn. Does this sound right? Also Please help me with the low speed setting. I keep leaning it out ( engine keeps flooding while trying to start it) and have lost my reference. How many turns out from closed? HELP. Engine is inverted as it's in a U Can Do.

Rudeboy

Pull the carb from the engine.

Leave the high speed needle as it is, but completely close the idle needle.

Put a piece of fuel tubing on the fuel nipple, long enough so you can look at the carb while blowing in the tube.

Completely close the throttle barrel.
If you blow through the tube now there should be (almost) no airflow.
Now open the the throttle barrel to what would be an idle position, and adjust the idle needle so that air starts to escape.
The goal is to adjust the idle needle in such a way that you hear a rapid change in airflow the moment the throttle barrel opens.
Move the throttle barrel back and forth a few times until you get it right.

This should get you in the ballpark... put the carb back on the engine and run it... adjust further from there...

Works on every carb...

w8ye

My Feedback: (16)

Lynn,

Often when inverted the tank centerline is well above the needle valve? It wouldn't hurt to look at this?

Also you could try starting the engine with the plane upside down untill you get the hang of it?

Jim

Cyclic Hardover

My Feedback: (3)

Your engine being inverted is your main problem. Unless you change something, you will fool with this to a pont of selling or junking a perfectly good plane.
Majority of those who invert a 2 stroke leave the fuel tank in its original slot--which is now considerably higher than the carb line.


But just for informational purposes. first, set you throttle opening to its approximate idle position. Open the high end a couple turns. Then close the low end. Disconnect the fuel line from the carb. Attach a spare line to the nipple and (at the same time, blow into the fuel tube and open the lowend until you here a hissing noise), Now your low end is in the ball park.

But as i said earlier I have a couple inverteds and I had to do some cutting to place the tank basically on the floor of the fuselage.

I also have a G90 in a Shoestring. Same engine has been in a couple other planes and is very powerful and reliable.

LynnR

My Feedback: (4)

Got it running OK. Still seems to load up a little in the transition but I'm working with it. Guess I'll end up lowering the tank a little. If you are familiar with the U can Do you know that it basically allows the engine only in an inverted position due to the cowl design and the thin fuse. Thanks again. LynnR

Cyclic Hardover

My Feedback: (3)

U Can Do? Friend has one so now i really stand by what I said. He runs and Irvine inverted and he is constantly &^%$ with that thing. But the plane is fantastic.