I'm putting a Zenoah G-38 in my Midwest AT-6 and have run into a couple of problems.

This is an older G-38 on which I have put a newer carb with a choke. I put the adapter on to rotate the carb to eliminate the bell crank for the throttle. I would like to put the choke on a servo also but I just can't see how to make it work. It doesn't look like you can rotate the choke arm at all and the arm is positioned such that when the choke is open it would be pulled the wrong way by the servo.

This is also my first gas engine and after reading about Tygon fuel lines it seems I need fuel barbs. I understand you can solder one on before inserting the tube into the cap on the fuel tank but don't see how you could solder the other one without melting the tank stopper.

The main reason I'm doing this is that the Saito 120 that was in the T-6 was about 2 1/2 lbs light and I hate adding dead weight. It just so happens the G-38 weighs about that same amount more than the 120.

Any help appreciated.

bigbird

If the choke is being pulled the wrong way by the servo, won't reversing the servo solve that issue. Also when soldering barbs to the tank brass tubing, the heat generated by your soldering iron should not be that hot to damage the tank's rubber stopper, unless you are using too much heat. What I do is first install the correct length tubing I plan on using in the stopper one at a time, pushing it as far as possible to one side so as to keep the iron and heat as far from the stopper as possible. Solder on the barb on that end then when cooled push the tubing through the stopper to expose the other side and solder on a barb on the other end. Then on to the next piece of tubing until all finished.

Karol

I guess I wasn't clear, servo direction is right, if I could move the arm it would solve the problem.

As far as the soldering goes it has to be warm enough for the solder to flow, that won't melt the rubber? I guess not since you do it...<br type="_moz" />

The new carb is a mirrror image of the old one, the shaft angles are completley different...I have some carb adapters from new G38s, send me your address and $5....
RC
PO Box 636
Williams, AZ 86046

OK... I'll put it in the mail today. I suppose it will also change the throttle?

The new carb's butterfly shaft runs clear through the carb and it acutally worked out better to use the opposite side from the side the stock arm was on for the throttle.

Thanks

bigbird

Another way to consider is soldering a small dab of solder on one end of the tubing, slide it through the stopper from the inside and then just slightly flare the other end with needle nose pliers or something similar.
If you are concerned about melting the stopper, this will work just as well.
Just remember to secure the Tygon onto the tubing with a small tie wrap after you assemble everything into place

Thanks apalsson,

If a little glob of solder will work, I'll try that as I already have a fuel barb on one end.

Yes, I know about the tie wraps.

Thanks!

bigbird

Is the adapter you have different from one you would get buying it from Horizon? I ask because I just got a new carb and adapter 2 days ago. (from horizon)

Thanks,

bigbird
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That should work just fine.
Even wrap some fine wire around the end of the tubing before you solder.
I normally just flare mine with some needle nose pliers and wipe off any sharp edges with 100 grit sandpaper

Thanks for the help apasson.

bigbird