fenderjw

My Feedback: (83)

I am new to the gasser engine arena and I picked up a used (actually brand new, but w/o the box and instructions) US Engines 41cc gasser this past weekend at Perry. I have done some reading and I think I understand how this beast is supposed to be started, but I would appreciate any input that anyone might have about starting the engine and adjusting the carb. So, here goes:

Question 1: I installed the kill switch on the ignition coil. I checked the continuity and the switch is good. So, am I correct in assuming that when the switch is on (closed) that the engine is off (grounded)?

I installed the prop at 90 degrees to the magnets. I will fill the tank with fuel, then choke it to get fuel into the carb.

Question 2: There is no choke on the engine so should I just use my finger over the carb? Next I'll lower the throttle to idle and wind up the prop (engine has a spring starter) After I let her go (after a coupla tries of course), the engine should start right?

Question 3: Now how should I go about adjusting the carb (walbro)?

Thanks for your help.
Jim

shenion

That is correct.Yes a finger works fine. Usually 2-3 flips.Similar to glow.

Full throttle adjust for highest RPM then about 1/8 turn richer.

Adjust idle for best transition off of idle.

Most Walbros:

Idle: 1 1/4 turn
High: 1 1/2 turn.

The idle needle is almost always closer to the engine.

Don't overwind the spring starter. Use 3/4 turn. Dont turn more as the spring will bend and wedge between engine and starter cam.

Use a good leather glove. The prop can easily slip out of your hand and the other side will wack your hand faster than you can get out of the way.

Silvanskii

My Feedback: (17)

I'd just like to add that after no less than 7 flights, the spring starter on my US-41 balled itself up, exploded the roller bearing, and ate up the central post inside the spring.

There seems like there might be something going on because numerous people I know have had similar problems with theirs. Luckily the US Engines people are good people and less than 3 days later I got my new spring starter kit for no charge.

P.S. You can't start this engine by hand. And indeed you can't start most magneto engines by hand. They need that extra oomph of the spring. I "choked" mine by just pumping a few pumps of fuel straight into the carb. For a brand new engine, it started and ran remarkably well!

P.P.S. I ran my in the cowling of a Top FLite P-51, and I took the carb venturri off. Looks much cleaner this way, and it hasn't affected performance at all. As a side benefit, the little bit of fuel the carb spits out occasionally flow right past the exhaust stubs of the full scale engine on the cowling. Natural weathering!