Hey guys, I need a little help here.

I went out today to try and maiden my plane today and had nothing but engine problems. I purchased a used TH .46 with a OS muffler.

When it was on the stand, I could start it up and runs fine at FT as well at idle. But when I would try to take off, it would just sputter and die after I got mid throttle.

SOOOOO I played with the needles a little, changed out the plug with a brand new OS #8. Still was doing the same thing. Then a buddy at the field said let's try it without the baffel. So I took it out and fired up the engine. Boy did that make a difference.

I did not try to fly it as the winds picked up and it was time for me to head to work, but the engine seemed to be running alot better. But I noticed the motor was a little hotter, so I made it richer.

I said all that to asks this, is it ok to run with out the baffel and just make sure it is rich enough????

It does not matter if the engine's muffler has the baffle in it or not. The baffel helps to reduce noise and also a side effect is that it might increase muffler pressure a little more too. Unfortunately mufflers tend to restrict the engine's power  more and a baffle will restrict it even more too.

If the engine ran fine on the test stand, then you need to check the fuel tank and fuel lines going to the engine. I would suspect the fuel line inside of the fuel tank has problem. Such as the clunk is stuck forward in the tank and not sitting freely at the rear like it should. The other case is the fuel line has a hole in it, likely where it goes on the tube passing through the stopper. In either case when the plane starts to take off the fuel line gets air in it and it causes the engine to quit.

I would suggest only putting about 1/4 tank if fuel in the tank and adjust the engine for that fuel level. Then Point the nose up at full throttle and do your final adjustment there, set just a little on the rich side. Then stop the engine and fill the fuel tank up. Start the engine and you should be in business then.

Hi!
As has been said! You have a tank problem!
It worked when you had the engine on the test stand but not in the model.Then why did you remove the baffle!?

i remove the baffles in all my mufflers... i also drill out the stinger/exhaust tip to permit more flow and gain a couple hundred rpm

If you don't have a noise rule at the field a baffle isn't needed.  I checked a couple of smaller motors and it got 800 rpm more.  Drilling the outlet helps a bit too.  Sometimes it can adversely affect the idle and acceleration because there is less backpressure on the pressure line, especially if the carb. bore is opened up as well.

I may need to clarify one or two things.

When I stated it was on the stand, I meant that the plane was on the stand at the field. Reason for pulling the baffel out was a fellow member had suggested it, and I was willing to try anything to get it running good.

I am going back out to the field tomorrow and try it again, with the baffel back in. There will be some other more experienced members there than can help.

When you had it running on the stand, did you let it idle for 30 second to a minute and then push the throttle open quickly? It sounds like the low needle valve might be rich and when you get ready to put it from the stand to the ground, It might take a few moments and the engine might get loaded up and then when you go to increase the thottle, the engine sputters and floods out. However, if you can let it idle on the stand for a minute and then transition to full throttle quickly without a problem but then the when on the ground it has a problem, then this is not the case.

Problem solved......

I had one of the other guys at the field take a look at it. It was loading up while in idle. Made a few tweaks to the LSN and runs great now. BTW, I put the baffel back in lol.

good job old man