Re: SuperTigre Engine problems....

Did you put a new needle valve assembly on the engine in an attempt to fix the problem? The original needle was almost certain perfectly fine, as needle valves are extremely simple in design and function, and rarely "wear out."

I would have to question your contention that the engine "runs fine." If it was running fine, it would continue to run... Since it isn't, we look for problems.

My suspicion is that the low speed needle is way too lean. I have had a few engines do exactly what you describe, and each time, the low speed needle was too lean. The engine would run screaming lean for about 20 seconds, until it got hot and died from fuel starvation.

Put a length of clean fuel tubing on the carburetor nipple, and close the carb to idle. Blow into the tubing and listen for air hissing. If you can't hear air hissing, open the low speed needle until you can.

The low speed needle controls the fuel mixture up through about 3/4 throttle.

I had about the same problems with a .45, and went through all the cures mentioned in this post over and over again. On the ground, the engine would run through a whole tankful, once up in the air, it would quit after a lap or two. Not lean, just quit, even when running too rich. This started when the engine was run in. I finally gave up on it, and added the thing to my collection. One day it will make a nice paperweight. , I hate to admit defeat!

I actually had a small accident last year and the broken prop came around and bent the needle valve belive it or not. I just bought the whole valve assembly.

I did the things mentioned above and was able to get it to run for 1+ minutes. I think it was the direction of the spry bar. It was really touchy as to exactly where it was pointed.

But I do beieve the low speed needle valve will need some adjusting, where might I find it on this engine?

Thanks,

roger

While assembling a brand-new G51, I (luckily) noticed something fishy about the pressure tap (the brass fitting that screws into the muffler, allowing exhaust pressure to be sent to the tank). It hadn't been drilled at the factory ~ there was no hole. If I hadn't noticed this, I probably would have pulled out most of my hair, trying to get the thing to run longer than 20 seconds

Just a possibility ~ don't overlook or assume ANYTHING with a ST... DC3

I once bought a Fox .74 R/C engine that had a similar problem. It had been drilled, but was not flowing enough air because of flashing. It did cause a bit of head scratching for a while.

Ed Cregger

Ed,

I am not going to risk a model on that one. I'll shine it up ok, but for a paperweight. This thing has a grudge, and I won't provide another opportunity. Rebuilding a kitted plane takes too much off my precious time.

cheers to you.

It's the gold color slotted screw embedded in the throttle arm.

Normally, they're on the side of the carburetor opposite the regular needle valve. It's usually a screw inside the center of the throttle arm. Maybe the ST is different?

If you can't straighten it out, I doubt if it could be done, Pe.

Ed Cregger

I'd say "sell it to me cheap", but I see you are across the pond

David

even so, won't sell it to anyone. I know better reasons to ruin my reputation. mmm.. come to think of that, I don't.

look at this link for basic setup.....I need another carb, or just the fuel inlet stuff, mine is bent, thanks to a tree...

Also, it says to have the slot straight down, but I think I've heard you are supposed to rotate it a little, it helps transition.

-- Duane

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Great news! The combination of the low speed idle valve and the needle valve did the trick. Was up and running in no time. Had the plane up and down five times since.

Thanks for the help.

One finally happy fellow! :-)