I was flying my H9 UltraStick Lite 120, with a Homelite 25cc conversion engine today, and the muffler came off. I looked for more than an hour, but couldn't find it. Will it cause any damage to run the engine without the muffler? I fly way out in the middle of nowhere, so the noise is not a problem.

It will hurt your ears if you stand beside the engine long term with it at high power

The engine loves it. You might want to readjust your mixture?

Yeah, I noticed the engine immediately began to run better. I'll make sure to stand on the side away from the exhaust, when I run it up[X(] It sure sounds great when I "buzz the tower" I'll make sure to re-adjust the needles the next time I fly it. Thanks.

Retune the high needle and it will be fine.

And....I can lose a little weight in the process

The best place to fly is in the in the middle of nowhere!!!!! Capt,n

Okay guys, I've got another question. Does Armor-All work in gasoline as a defoaming agent, like it does in glow fuel? I was running one of my 21cc conversion engines today, and I noticed that after the fuel got down below half a tank or so, it would get bubbles in the fuel line, and cause the engine to surge. I put foam around the tank and it helped somewhat, but a little anti-foaming "potion" would probably help too.

ive noticed the few times ive lost a muffler on a gasser, the idle goes to crap... it goes way up ive never tuned an engine to run with out the muffler..
is rpm lost or gained w/ out a muffler on a gas engine?

IIRC gas does not foam (like glow fuel). If you're seeing bubbles in the line you probably have a tank plumbing problem.

Use a felt filter in the tank and you will not get foam or bubbles in the pickup line until and unless the tank is dry. No silicone based additive is needed or desired.

i just took TOMS advice... i ordered 125-527 for all my gassers, and 125-528s for my gas cans... according to TOM he hasnt had a dirty screen in 5 years... i guess we'll see in 2016 [8D]

yeah, I run the weedeater pickups with the felt insert or ceramic depending on what I have on hand at the time, it helps get the most of the tank of fuel and are heavier than a normal clunk. If you can't find them at a mower shop Home Depot has a package with some fuel line and a clunk for about $10

So, how does the Homelite pull the stick around? I was flying mine with my McCulloch 32cc today and I love that plane, a little too gusty to screw around too much today though.

It pulls the stick fine. Not as well as the Moki 1.80 that it replaced, but I didn't expect it to. Conversions are a new area of this hobby for me, but I'm having a ball with them. I may even try a little reverse engineering from the engines I got from you, and convert one myself......love this hobby!

The problem must be somewhere else. I can tune the engine to run fine, but when I point the nose up, the engine dies. Doesn't matter if it is WOT or at idle, it dies. I'm guessing the diaphram?

how do you have the tank plumbed? is there a break in the supply line (other than at the tank stopper)? You would be surprised at where these things will pull air from sometimes instead of fuel. The only diaphragm that would affect the pumping ability would be the pump diaphragm, It's been 4 months since I put that carb together but I thought it was in decent shape.

I encourage trying converting one, the only special part is the prop adapter, the rest is just labor making it look the way you want. On some you have to have an engineering mind to figure out how much of the front you can cut off and not make it weak, like the Homelite where the coil is mounted off the front shroud you can't just go chopping it all up. A lot of people get hung up on chopping a lot of aluminum off of the things, most of the weight is in the crankshaft... steel is a lot more dense than aluminum. Feel free to steal some of the ideas I used on those engines, I borrowed them from others, like the studs out the back of the backplate, I got that idea from av8tor and it works great!

I pulled the tank and started over, making sure that there was nowhere that it could be pulling air. I'm not seeing any air bubbles now, but it still will not run with the nose pointed up. I think I'll pull the carb, and try a new pump diaphram. While I'm at it, I'll make sure the little hole to activate the pump is open. It doesn't cost much for a rebuild kit anyway, and I have done that before, so I won't be travelling in totally uncharted waters. I'm having a ball tinkering with these engines, except for the above 100 degrees heat index we've been having[:@]

Problem solved...well kinda. I replaced the carb with an extra that I had on hand, and it runs great. I'll get a rebuild kit for the other carb. That ought to take care of it.

Maybe thats why early glow engines used exhaust baffles before mufflers became common. Without a muffler power goes up and weight goes down, idle quality may suffer.

The only change I noticed with the idle, was that the rpm increased quite a bit. I had to re-trim the top end and lower the idle a little, and it is purring like a kitten....a very loud kitten[X(]