I have a 3W 56 twin and as with all other 3W engines, you have to attach the throttle arm. What's the best way to go about doing this? I've tried Silver Solder, but I couldn't get it hot enough without using a torch and the fuel inlet nipple is right there. I don't think lead solder would work. What about JB Weld? I'm going to try to drill out the shaft for the throttle plate and then tap it for a small screw, but that may not be succesful. Any ideas?

Ben,If you use weller a gun and use the smaller tip.You have to use staybrite silver solder on roll and use the correct flux it will solder on just fine.I always drill a hole and put a tiny bolt and nut through mie for added security.Hope this helps.

I gave up a while back on the throttle arm attachment. I now only use these

http://www2.towerhobbies.com/cgi-bin...?&I=LXD847&P=7

Grind the stock carburetor arm off, and put one of these on. I have 3 gassers set up this way. Works for me.
You need a wheel collar to fit the shaft, a #6 capscrew about the same length as your servo arm, and a DuBro #559 horn bracket.

Remove the carb from the engine.
Remove the butterfly from the throttle shaft, then you can pull the throttle shaft out of the carb. Now you can solder it without worrying how hot it gets. I just did this with my new G62. Instead of using the plastic arm and set screw method, I ground off the top of the shaft and flipped the stock arm over and rotated 180 degrees, then soldered back on. This also let me keep the return spring hooked up which I like as a safety feature.

Here's a couple of before and after shots. Not the prettiest solder job, but it works.......

Ben whatever you do don't take the butterfly shaft out,just get some stay brite solder and flux solder it on. The hole procedure takes less then 10min!If you take the butterfly off you have to brad the screw when you put it back together or the screw cac come loose and into the engine and engine into the trash.Loctite won't work!

Must depend on the grade of Loctite..I have been taking the screws out for 18 years, converting G62s, never had one come out after... ..If you use Green 680 Loctite and clean it first the head of the screw will twist off before it unscrews...Been there..
The screws are brass....

Same here RC..... Clean the screw up, put a dab of blue Loctite on it and you're done. I've never had one get loose on me.

Well if anyone knows it's you Ralph!I've just seen what happens when they do come off and I put a little punch chsel in the vice and brad it a little!It seems silly to me to tear a carb all to peices just to solder a little arm on.I've done plenty w/no problems.10 min.

I just repaired a customer's 3.2 engine that lost the screw....The disc went into the cylinder and got between the piston and cylinder wall...Took a big steel pin and a hammer to get the cylinder off the piston...Luckily I had a new piston and was able to clean up the bumps on the port...Never did find the screw...
The older Walbro carb screws were spread slightly sideways, the newer ones are spread by a punch in the center...Loctite works well on either...Some Tillotson carb screws use a star type lock washer..We solder the discs in the race carbs and grind the screws flush...

I talked to one of my old Ag teachers and he said I could probably take it to a jeweler. The jeweler should be able to solder it on. If he can't, I'll probably try taking the shaft out and then taking it to a specialty welding place. If this doesn't work, i'll be back on here. Unfortunately, it'll be a week before I see the engine again as i'm on vacation.

I do it both ways, either take the shaft out or solder it in place, but when you do that you have to be careful, some of the carbs have either a teflon or rubber washer on the shaft that can melt real easy. I use Stay-Brite and a small pencil torch.

Tom

Hi,

I use a different approach. I use a long servo arm which is attached to the hole on the arm with a 2-56 bolt with lock nut. Before I tighten it down, I squeeze some RC-56 between the two surfaces. Then I adjust the angle and tighten the bolt. I have never had any problem with the arm loosening.

Elson

I used a 100W soldering iron that is quite powerfull (10mm soldering tip) when i did this on my 56.
Solder that I use for doing the electonics worked quite well but the thing needs to be heated which req. a lot of heat energy. With a massive tip this energy is already saved in the tip. Make sure you sanded all parts before soldering. I pre-soldered the arm and the carb first (keep the hole). I installed the whole thing together with a little scew and soldered it while screwing it together.

Btw: good engine choice...
My is now turning 7100+ on a 22x10 3Blade Engel Prop (@sea level) using two tuned pipes.... >16kg thrust in a 8kg Ultimate -> nice
Forget about the MVVS 58 or the DA50 ;-)