Just getting back into the hobby after a few months and sort of lost my touch on tuning this engine. It seems to run and transition fine when it's level and on the ground, but when I hold it vertical it runs real sloppy and the RPM drips and rises in huge increments. Any tips?

Misanthro,

I love the Thunder Tiger Pro series engines. I currently own and fly six Pro .46 and have had absolutely no problems with these engines. I started out by breaking in the engine following the instructions from Thunder Tiger. They are easy to start and I very seldom need to adjust the needle valve (only when the air temperature changes). Sorry that I can't address your issue. I have never been faced with that on any of my engines.

Good Luck!

Lumpy Pants

I just bought a new TT 46. I put on a Tower hobbies 46 muffler. I can't get the thing the start and run longer than 30 seconds. I have tried opening high end at 2 1/4, 2 1/2, 2 3/4, 3, 3 1/4, 3 1/2, 3 3/4, 4 turns. It will not start at a idle below half throttle. If it does it only run for about 2 seconds then dies. I have to start it at half throttle to full throttle, if it starts, it will only run for about 30 seconds. I have tried 2 differant OS A3 plugs. I am using a new gallon of bryson 15/16 fuel. If I get it started i can run it had full throttle,
but as soon as I get it back to half or below, it dies with 3 seconds. I am thinking the low end is way to lean. i know my barrel does shut when I pull the throttle back to idle. It looks like it is around 1/4 throttle. I tried richening up the low end, but my starter batt. went dead.

Am I right in thinking my low end is to lean, or do I need to put back on the stock TT muffler and start again.

I would not play with the low end at this time. Open up your Thunder Tiger muffler and remove the baffle. It works like a restrictor. You don't need it. Replace your Tower muffler with your stock Thunder Tiger. I run Omega (pink) 15% fuel. You can use 10%. I broke my engine in at 2 1/2 turns and it runs great now at 1 1/2 turns. I have never needed to adjust the air mixture screw on any of my Thunder Tigers.

Good luck!

Did it work OK the last time you ran it? If it did you might want to try a different batch of fuel. If the fuel your running has been around for a while fresh fuel can only help.

DGrant,
I did just buy a new gallon of fuel today but haven't tried it yet, so I'll have to give that a shot tomorrow. Thanks.

m.gramling

Check your needle valve area for dirt. Or, check the fuel inlet where the fuel line connects. Mine acted the same way. What a little piece of dirt will do!

I checked all my fuel lines and nipples. That didn't work. I put my stock TT muffler back on. It would run for about 20 seconds. I am in the process of richening up the low end to get it to work.

All I have read about this motor was good things so i decided to buy one. So far I am not happy. I can get a ST 45, 51 to idle better than the TT46 so far..I am not giving up on it. Everybody at my field that has one stated they never touched the low end. so far I have got mine opened up 3/4 turn from where the factory set it. It is barely running. I think I am going to have to keep riching it up.

I thought most of the time motors come half way preset from the factory. so far this is isn't.

If you've got the main needle out 2+ turns and there are no air leaks or contaminates, the idle needle is out o' wack.
When bringing it down slowly from full, does it seem to lean out? Does it 'blubber' when it quits?
Keep richening, (or leaning-depending on the circumstance), that Idle needle as you come down from full until you reach idle speed. Watch your exhaust for lack of smoke or unburnt fuel. Someone showed me that method at the field when I was new and getting fed-up with tinkering. I use it when I get a finicky engine. You just have to be very careful of that spinning prop!

How many total turns out is your idle?

I haven't screw it in. But I have already screw it 3/4 c-clockwise (rich) from the factory postion. It raining here is Memphis, TN so I can't do anything until the weather gets better.

Michael.... One way to check your low end setting is to bring it down to 1/3 throttle and pinch the fuel line. If it quits, the low end is too lean, if it blubbers then quits, it's too rich.

One more thing... How many tanks did you put thru this thing for break in? Let me know if you need some help with it, I've got a test stand we can work on it...

Paul
so far I only have about 2 tanks thru it. I had to richen up the low end, because it wouldn't run at all below half throttle. I am going to work on it thursday to see if I can get it any better.

I bought the 46 Tower muff. to gain the extra 600 rpm that alot of people talk about. But I will have to reinstall if after I get the motor broke in. My TT 46 wouldn't run below half throttle w/ the tower muffler on it.

I wil keep everybody posted.

Try opening that needle WAY up... then bring it to an idle... if it start's blubbering..... pinch the fuel line.... If it never blubbers and quits right away, you might have a problem or a blockage somewhere........ If it does blubber, gradually bring it down 1/4 turn at a time until it starts quitting abruptly again. Then open it up 1/8 at a time.....

Good luck!!! I'm going flying Thursday at lunch....

Paul where you flying on Thursday. If you going to be in Millington I can meet you. I am going to try and get my TT46 set so I can fly my wasp.

My top cap is out of service until I get my aileron put back on, and fix it from breaking my bottom back motor bolt.

I orderer me a menace kit today.

I was going to fly in Olive Branch Thursday at lunch time... but I could come out to Millington after work.... It's easy to fix those hinges.... You can sneak them in by cutting a new slit and flexing the aileron a little... I could bring some stuff to the field....

Remember what we talked about on the G 90? take care.