I dont know if this has been discussed already, but why do bisson exhausts come crimped or tapered in, tomake the exhaust exit smaller? Im gonna cut them off to make it less restricted... any opinions?

Been discussed several times. The pipe exits were crimped because some engines need the back pressure to run right. Have you run your engine with the stock Bisson? I've plugged one off on older Bissons that were'nt crimped to improve engine runs.

Terry in LP

no i havent run this particualr engine os 120ax yet.... but i had a bisson exhaust on my 61fx, and cutting the crimped exit gave me a slight rpm increase, ill take every extra bit of performance i can get.

Do 120ax's need a lot of back pressure or will i be fine cutting the tips off?

Never had a 120AX so can't say.

"ill take every extra bit of performance i can get. " Even at the expense of midrange and/or idle?

Terry in LP

For me personally I don't want to get every little bit of power out of an engine. On a hot day it doesn't take much for it to go lean and then you start to damage your engine. I'd rather run it a little on the rich side and fly it rather than have it go lean and repair it. I like to run Byrons 10% nitro with 20% oil. With the added oil I'd rather clean it than repair it. Just my way of thinking.

i dont want to sacrifice mid range, i'll keep the bisson muffler stock. i want my engine to last me ................. thanks

I had a bisson on my OS 160 and I plugged one of the stacks with a wooden dowel to get the muffler to creat the back presure for the fuel tank.
Never had any problems with the 160 leaning out. Been running the OS 160 for three yrs. now on my Baby Edge.
NEDYOB

thats tons of power, how do you like it with that engine?

Ok so I know this has been discussed in many threads. But I jsut build a Seagull models Edge 540 ARF 46-55 size. I put a SuperTigre .61 in it and am waiting on my bisson muffler. The stock muffler would cause me to cut to much cowel off and I didnt want that. But everything I have read makes it sound like the Bisson will give me problems, I know its because of back pressure. I dont get it should I expect a problem that will need to be fixed, I dont do 3D ut wanted this plane, Im not worried about mad power jsut as long as the engine runs right. It is already overpowered for what I will be doing with it. Jsut want some info on what to expect, not to mention how I might try to fix it. Im jsut a little discouraged after reading all this stuff I was so excited about not having to butcher my new cowel [&o] Anyway. Thanks.

If you ordered muffler #2161 you will be fine.

http://bissonmufflers.com/en/muffler...ting_id=114066

http://bissonmufflers.com/en/muffler...ing_id=1137319 thats the one i ordered ... btw i ran two tanks through my 120ax on the ground and it ran/sounded great, its ready for action

That is the one I ordered but I jsut am afraid from all the talk that it may run cruddy.

Quoting Willy S. "Present fears are less than horrible imaginings."

The problems were encountered with the older muffs.

Terry in LP

I think the most problems like that we read about are the SlimLine mufflers where they use the .90 sized muffler on the .60 sized engines or vice versa.

CastorTroy2150,

Best thing to do it install the Bisson muffler and see how the engine runs. It should be ok but if it's not you can start the mods. Like what was said prier, it was the older Slimline mufflers. The newer mufflers have one tube smaller in dia.

OK sounds good, but you know how it is, getting something new and read a bunch of "supposed" problems with it. Kinda felt like someone just punched my new puppy in the face . Thanks for the info, can't wait to see how it works, really excited to see this plane in the air. She is a beaut! Impressed again by the quality of the Seagull ARFs, she should scream pretty good with the .61 as it is a .46 size plane. Thanks again guys for the info, will let you know how it goes, should be here Tuesday since the holiday is Monday.

castortroy 2150 - I live in Lexington so am near you. I have run many super tiger engines and would be willing to help you break it in and set it to run correctly. give me a call at 884-2389. I usually fly at the Bellville field near 71 on Bellville-Johnsville road. the main thing is to get the fuel tank setup at the right height for the super tiger - this applies for most engines not just super tigers - using the right glow plug - not the one that comes with the engine - and if you have the ringed version you need to break it in on the ground to get the rings seated fairly well before you fly it. I use fox r/c long plugs for breakin, and os f plugs after breakin. I use 10% omega but some say the tigers run well on lower nitro fuels. there is no adavantage to going to nitro above 10%.

good luck

Ed

Ed,
I believe you are the fellow that flys the P-51s am I correct? I have talked to you before I am sure as I fly at that field reguarly. I attempted to call you but got an answering machine. Please give me a call back, as I would love any help that you may be able to give to me. My number is 419-528-9705, call anytime, this is my cell number. Maybe some day when you are going to fly I could meet you out at the field. I have been running Wildcat 15% always have, should I invest in some Omega 10%, is this what you suggest? Recieved my bisson today and have installed it now I jsut need to break in the motor, it has not yet been started. Hope to hear from you soon

Pete