I have an os .40la and was wondering about the pros & cons of removing the muffler baffle. Will this increase power and still give enough pressure to the fuel system?

Yes it will if the tank is right behind the firewall. If the tank is closer to the center of the wing, no it will not.

If on a high wing trainer type plane run 15% and put a APC 10-6 on it and it will come alive. If it is on a sport plane, go with a APC 9-8.

There will be a difference, but not much. It's not actually worth the effort.

What it will do is make setting the needle a bit different.

And it probably will be a bit louder. And that usually convinces most people that they've made a major change. After awhile most of them realize that if it did increase anything, it was just the sound.

Almost always, if you think you need more power, swapping in a larger engine is the best thing to do. You won't get the extra power you were wanting just by pulling the baffle. We've got a field full of airplanes using the 46AX. A couple of them have the baffles out of their mufflers. They aren't the fastest airplanes out there. They weren't really any slower when they had baffles in their mufflers. Not by enough that it mattered.

I tried that same thing with a LA .46 in a Tiger 2 all I got was more noise. Later put a .46FXi on it.

The .40 LA simply wasn't designed to be a powerful engine. It provides adequate power for .40 trainer or sport plane, and taking out the muffler baffle isn't going to change that. The O.S. .40 LA will provide years and years of reliable service, particularly if you use 50/50 castor/synthetic fuel or 100% castor fuel. The castor oil lubrication is particularly beneficial for glow motors with bushings rather than ball bearings.

If you want more power, buy a ball-bearing .46-sized engine from the manufacturer of your choice.

I have actually run a few LA's and FP's [good bushing engines made previous to LA's] with and without the baffle and it made a 300 to 400 rpm difference. I also reamed out the the exhaust pipe a few drill sizes and that added a few hundred more rpm, up to 600 rpm over stock on 15% omega. Yes it is louder but not that much over stock. I fly at two different wide open fields and the noise was not enough louder to draw any attention. It was enough power difference to notice on the planes I flew. No problem with tuning or fuel draw.
Fred

The LA is a very good running engine, just not much "umph" to it. Don't try and squeeze water out of a turnip. You wasting your time.

I want to remove the nose washer from a O.S. FF-320 engine to put a onboard starter gear on it. I have never taken the prop washer off of one. Does anyone know what is the best way to remove one. I tried very lightly with a brass drift but it did not make any sign of moving so I went no further. I also tried a wooden dowl with no luck. I do not want to hurt the engine so figure its best to ask first.

I have an OS 40la and flew it on my trainer shortly into it's 3rd season, I felt it was lacking a little. Everyone told me to take the stinking baffle out and watch how much power it would create. {this must be some sort of trick to pull on rookies, like hey watch this he'll fall for anything} I removed the baffle adjusted the needle slightly and taxied down the runway. The plane used 6 inchs less runway than before, with the grass here that ment 99ft 6in vs. 100ft. HA HA the joke was on me. I stopped at the LHS on the way home and bought a OS46AX. Now I can take off in 25ft ,but the landings were a little hotter till it broke in all the way and I could get the idle down.

Gear puller

One that fits.