Alright, I have an OLD....and let me put emphasis on the OLD part.... OS 45 that I am running on a Great Planes Big Stick. Surprising the motor screams and runs great. Or well it did. This past weekend while flying it, the engine vibration broke both the ears off the muffler where it bolts to the engine. Now I am looking to buy a replacement muffler and cant find one. I looked on the OS website under discontinued engines and it isn't listed there.....I have a 46 FX that we tried to mount the muffler from for size and it didn't fit (to wide) and the 40FP muffler lists as fitting 30 -40 engines. HELP!! I did consider a Mac's muffler for it, but due to the clearance to the firewall i would have to carve out the firewall a bit to make it fit, and just not wanting to put that much work into a silly Big Stick. Anyone know of a inexpensive muffler that would fit on this old OS 45, and where to get one at???? Thanks, and HAPPY FLYing!!!

PM

you may try to mount a strap to the old muffler and still use it.if vibration broke the ears off the muffler you better find out what is causing it before it does the same to your radio gear and airframe.ballance prop?loose mount?these engines do not vibrate the way you describe.by the way the 45 fsr uses the same crankase as the 40 fsr.

Measure the distance between the bolt holes on the engine or the muffler. Then go and check Tower Hobbies mufflers. MOST of them provide the distance between mounting holes.

You will also need to find out the cause of the vibrations otherwise you will be breaking the new muffler also.

Right now i think it has a Master Airsrew 9x6 on it, when i figure out a new muffler I am going to change the prop and spinner to a new one and see if it happens to be the prop. I have a friend who has some old mufflers and we are gona go thru them sometiem and see if one will fit it! (Thank God for packrats!!) I appreciate teh help and will let you know what i come up with!

9-6 is awful small prop for a .45 should be 10-6 or 10-7 or even 11-6.any way no matter which brand prop they need to be checked for proper balance even if new.