Craig F

I have a TH 46 on a Dazzler with a dozen flights on it with no trouble at all, nothing changed, same prop, same fuel, just a different day. Idles great, give it the gas and it dies. Tried messing with the needle and nothing! same thing. Any ideas?
Thanks for any help. I know this should go in the engine forum
but I also know this is where the smart guys are!!! Craig F

polarisRCU

Craig,

What fuel are you running with ? I had been using 20% Nitro fuel, and I noticed my TH .46 was very sensitive to humidity changes (day to day). What I had to do when mine would do that was richen the mixture quite a bit, adjust the low end needle, then go back and adjust the high end needle. Once I got max RPM, I backed out the needle half a turn. This ensured that I would not lean out too much as I flew fast (yes, I found that as I picked up speed, it would again become too sensitive)

Hope this helps.

polarisRCU

By the way, I changed to 10% Nitro fuel, and have noticed that the carb is slightly less critical than it was before.....

Craig F

I'm using 15%......anybody know where the low end is on a Tower
Hobbies 46? Should this change so much due to humidity, to the point where it won't run up? how do you adjust high/low on the ground so it runs right in the air?......Thanks Craig F

CHOCOFAN

Hey! Craig what plug are you useing ? I'm having a similar problem with my GMS .47. I put in a O.S. #8, I tried using other plugs but unsuccesful ,@ idle it would be ok but as soon as I would give it full throttle it would cut off. until it used an O.S.#8.

Craig F

It's an OS A3..... Whats the differance between a 3 and an * ?
Is the 8 hotter?

Gordo-ProBro

Craig, I'd doubt your problem is the KIND of plug, as you said that it worked fine before, And I assume you flew recently (last flight wasn'r middle of winter?). My first move would be to put in a NEW plug. They often go out just like that. Also try fresh fuel, just had a student with similar troubles (actually, it was about the same deal) and it was his fuel. It can absorb water, but that's as far as my understanding of that goes.

One trick I always preach: Change ONE thing at a time!!!

1. new plug
2. fresh fuel
3. fly your buddies plane while he fiddles with yours!

Gordo-ProBro

Oh, will it throttle up with the glow igniter left on?

PaulSwany

My Feedback: (45)

If it quits soon as you give it gas, the low end needle is probably too lean. First set your high end:

1. give it full thottle.
2. pinch the fuel line
3. if the RPM's go up, lean it.
3. if the RPM's go down, richen it.

Here's how I set the low end:

1. warm up the engine.
2. advance the thottle to a little above idle.
3. pinch and hold the fuel line
4. if the RPM's go up, lean it.
5. if the RPM's go down, richen it.
6. fine tune by testing your thottle transition.
7. if it blubblers a little when you advance the throttle, lean it.
8. if it quits when you advance the throttle, richen it.

Hope this helps.

lomcevek1

Another thing about those tower engine is they are great running engines but are notorious for leaking air in and around the carb. Seal the fuel nipples and the backplate with a LITTLE bead of orange RTV and my problems went away.

Hacker

CraigF,
i had the same troubles with mine....i tried every thing and i mean every thing. tower finally sent me a new carb body thinking that would solve it...still had the same problem you have. finally sent it back to tower for a refund....they were very nice about it.
would like to know what the problem was.
i did the break in per the book then 1st few flights were ok then next time out wouldn't take the gas...weird. Really too bad cause that engine seemed like a brute......i did finally solve MY problem
OS46FX....great little engine

in the end i think you will find it is a air leak of some kind....good luck and let us know how you make out

Craig F

Well I tried a new plug #8, same problem. I have another engine I got at the same time and runs great, same fuel. I can't run it up to check the needle as someone suggested cause it quits!! I'll try sealing the carb and new fuel lines, if that doesn't do it ,then back to Tower. I'll let you know, thanks for the ideas....Craig F

Bax

My Feedback: (11)

Usually, an engine will idle and run to partial throttle and cut off when the throttle's opened more if the idle needle's too lean. Changes in the weather and changing fuels can require you to completely reset the carb.

First off, please try richening your idle needle a LOT! Then start the engine with the high-speed needle at a rather rich setting. You'll likely have to start the engine at 1/4-1/3 throttle because the idle's too rich.

With a rich idle needle and a rich high-speed needle, you should be able to get the throttle fully opened with the glow plug battery still connected. Now lean the high-speed needle to just rich of peak RPM. Remove the glow plug ignitor.

If you can get the engine to this point, you can then start to retard the throttle and start working on the idle mixture. You know it's too rich, so you know you'll have to lean it.

You should be able to get the engine idling like before.