OS .60 SR muffler
#3
Thread Starter
RE: OS .60 SR muffler
Sorry Vince,
but the 744 only fits the Max .61 SF , .61 FSR, and will also fit the .61 Evolution and .61 ASP. But not the .60 SR.
The 744 is a bolt through muffler. The bolt goes "through" the crank case into the muffler. The muffler for the .60 SR is a bolt "on" as the bolts go through the muffler and bolts the muffler "on" to the crank case.
Some one out there in OS land has a .60 SR with a stock muffler, I just need the number of the muffler. Come on guys, go out into the shop and dig around in some of those boxes of old engines and get that number. I'm counting on you.
Frank
but the 744 only fits the Max .61 SF , .61 FSR, and will also fit the .61 Evolution and .61 ASP. But not the .60 SR.
The 744 is a bolt through muffler. The bolt goes "through" the crank case into the muffler. The muffler for the .60 SR is a bolt "on" as the bolts go through the muffler and bolts the muffler "on" to the crank case.
Some one out there in OS land has a .60 SR with a stock muffler, I just need the number of the muffler. Come on guys, go out into the shop and dig around in some of those boxes of old engines and get that number. I'm counting on you.
Frank
#5
RE: OS .60 SR muffler
The OS 744 has 2 versions. The original 744 is a bolt to the engine. The second version the 744B was a bolt thru. The 61SF used the 744B, but the first versions had holes for either muffler. The older fsr series need the original 744 (bolt to) muffler.
#7
Thread Starter
RE: OS .60 SR muffler
Vince you are right. I've seen several SR 60 with a 744 muffler on them. Well guys, I have two (2) 744 mufflers they both fit the .61 SF, but will not fit the .60 SR.
Does't the 774 B have "744B" on the header, or did they leave the B off? I have not seen a " B " on any muffler. If I find a 744, how will I know which model of the 744 will fit the 60 SR? Any other ideas? I really don't want to buy every 744 I find and find out that it won't fit.
Frank
Does't the 774 B have "744B" on the header, or did they leave the B off? I have not seen a " B " on any muffler. If I find a 744, how will I know which model of the 744 will fit the 60 SR? Any other ideas? I really don't want to buy every 744 I find and find out that it won't fit.
Frank
#8
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RE: OS .60 SR muffler
Hi
The early version 744 muffler will have a much narrower bolt pattern, approximately 34 mm center to center bolt, like the 61 FSR. The newer version 744 has a longer, narrow exhaust port size.
Vince
The early version 744 muffler will have a much narrower bolt pattern, approximately 34 mm center to center bolt, like the 61 FSR. The newer version 744 has a longer, narrow exhaust port size.
Vince
#9
Senior Member
My Feedback: (1)
RE: OS .60 SR muffler
ORIGINAL: countilaw
I am in need of the part number for a stock muffler for the O.S. Max .60 SR.
Frank
I am in need of the part number for a stock muffler for the O.S. Max .60 SR.
Frank
The Fox tilt-up or the tilt-down mufflers for the Fox .61/.74 Eagle IV engines will fit the OS .60 SR. I just test it. You can order either style muffler directly from Fox.
Bruce
#10
RE: OS .60 SR muffler
If the Fox mufflers fit then some of older the Rossi mufflers would fit too. The Fox mufflers use a about a 34.8mm screw spacing.
Macs Mufflers makes an adapter plate (bridge adapter) for the Fox engines that you could use to adapt a Mac's muffler or other muffler with the same screw hole spacing to fit.
You could also fabricate a bridge adapter so that you could adapt most any muffler you want to fit too. I did that myself for my Fox engines and my Rossi engines could use the OS sized Performance Specialties Ultrathrust Mufflers (aka Nelson).
Macs Mufflers makes an adapter plate (bridge adapter) for the Fox engines that you could use to adapt a Mac's muffler or other muffler with the same screw hole spacing to fit.
You could also fabricate a bridge adapter so that you could adapt most any muffler you want to fit too. I did that myself for my Fox engines and my Rossi engines could use the OS sized Performance Specialties Ultrathrust Mufflers (aka Nelson).
#12
RE: OS .60 SR muffler
Yes the original 744 fits the 50-61 fsr, Rossi 60, Fox Eagle III & .60-.74 Eagle IV, Enya 60X, HP 61 Gold Cup, and Mvvs 10cc. I even have a couple of Webra Speed 61's that were drilled for this muffler spacing, but some have no muffler holes drilled( some HP's also have no holes). It was a great universal type muffler to bolt on for many engines of that time. I guess mfg's copied the popular OS spacing. There may be some other applications it will fit, but those are the one's I have and have tried the 744 on.
The OS 60FP will fit an OS 61SF as I traded for one of those without a muffler and the FP muffler fit. I am not sure about the volume as I have no 744B to compare it to.
The OS 60FP will fit an OS 61SF as I traded for one of those without a muffler and the FP muffler fit. I am not sure about the volume as I have no 744B to compare it to.
#13
My Feedback: (404)
RE: OS .60 SR muffler
I put htis together for my own reference -
OS #761 - .10FSR .10FSR-S .10FSR-C .10FSR-M .10FSR-B CZ-1
OS Max #871 Muffler for 10 & 15FP, 15LA, 12-15 CZ and CV series engines. May fit other .10-.15 size engines
OS Max E-2030 muffler for the 20 & 25FP and the 25LA series engines. This muffler replaces the #842 OS Max muffler.
892 = O.S. replacement muffler for the OS MAX 25SF and 25FX engine.
3030 - O.S. muffler included now with the OS 35FP, 40FP and 32F engines. It is quieter than the #843 that used to come with the engine.
O.S. Max #873 - .40SF ABC .40SF-S ABC
.46SF-H .46SF ABC .46SF-S ABC
.46SF .46SF-HS .46FX Non-Ringed
O.S #873S super Silencer muffler used for the Max 40FX and 46FX engines.
4010 - O.S. replacement muffler for the OS MAX 60FP, 65LA, and 61FX Engines. 65LA
O.S. #855 muffler for the OS Max .91 & 108 FSR engines. Adapter plate takes the round/oblong exhaust port and makes it possible to mount the #855 muffler.
842 - FP 20 - 25
744 - 50 - 90 FSR - bolt to engine
744 (B) - 61 SF - bolt thru
703 - S 30 -35 -40
762 - 25 - 28 FSR
702 - 15 - 25
743 - 40 - 45 FSR
843 - OS 32-46 FP & LA
873 - 40 - 46 SF
4010 - OS 61 FX FP
761 - 10 FSR
E-4010 - OS MAX 60FP, 65LA, and 61FX Engines
E-4020 = OS Max 91 FX
OS #761 - .10FSR .10FSR-S .10FSR-C .10FSR-M .10FSR-B CZ-1
OS Max #871 Muffler for 10 & 15FP, 15LA, 12-15 CZ and CV series engines. May fit other .10-.15 size engines
OS Max E-2030 muffler for the 20 & 25FP and the 25LA series engines. This muffler replaces the #842 OS Max muffler.
892 = O.S. replacement muffler for the OS MAX 25SF and 25FX engine.
3030 - O.S. muffler included now with the OS 35FP, 40FP and 32F engines. It is quieter than the #843 that used to come with the engine.
O.S. Max #873 - .40SF ABC .40SF-S ABC
.46SF-H .46SF ABC .46SF-S ABC
.46SF .46SF-HS .46FX Non-Ringed
O.S #873S super Silencer muffler used for the Max 40FX and 46FX engines.
4010 - O.S. replacement muffler for the OS MAX 60FP, 65LA, and 61FX Engines. 65LA
O.S. #855 muffler for the OS Max .91 & 108 FSR engines. Adapter plate takes the round/oblong exhaust port and makes it possible to mount the #855 muffler.
842 - FP 20 - 25
744 - 50 - 90 FSR - bolt to engine
744 (B) - 61 SF - bolt thru
703 - S 30 -35 -40
762 - 25 - 28 FSR
702 - 15 - 25
743 - 40 - 45 FSR
843 - OS 32-46 FP & LA
873 - 40 - 46 SF
4010 - OS 61 FX FP
761 - 10 FSR
E-4010 - OS MAX 60FP, 65LA, and 61FX Engines
E-4020 = OS Max 91 FX
#14
Thread Starter
RE: OS .60 SR muffler
ORIGINAL: Hobbsy
Frank, do you have a picture of the .60SR, I have a .60fp, the E-4010 muffler looks to be much different. My LA .65 and .60FP each wears an E-4010.
Frank, do you have a picture of the .60SR, I have a .60fp, the E-4010 muffler looks to be much different. My LA .65 and .60FP each wears an E-4010.
This is a real problem with the Max Muffler. It Max didn't put the " B " on the 744B muffler it's going to be hard getting the right muffler for the SR. Bummer !!
Frank
#16
My Feedback: (404)
RE: OS .60 SR muffler
ORIGINAL: countilaw
Here are pictures of the two engines, the .61 FS is on the left and the .60 SR is on the right. Forgive the balsa dust on the FS, I am in the process of fitting it to a new plane. I would like to put the SR in the new plane, but I don't have a muffler for it yet. So I am having to go with the SF.
This is a real problem with the Max Muffler. It Max didn't put the '' B '' on the 744B muffler it's going to be hard getting the right muffler for the SR. Bummer !! [img][/img]
Frank
ORIGINAL: Hobbsy
Frank, do you have a picture of the .60SR, I have a .60fp, the E-4010 muffler looks to be much different. My LA .65 and .60FP each wears an E-4010.
Frank, do you have a picture of the .60SR, I have a .60fp, the E-4010 muffler looks to be much different. My LA .65 and .60FP each wears an E-4010.
This is a real problem with the Max Muffler. It Max didn't put the '' B '' on the 744B muffler it's going to be hard getting the right muffler for the SR. Bummer !! [img][/img]
Frank
#20
RE: OS .60 SR muffler
You have a small nomenclature problem you need a muffler for a FSR/SR. Your calling your SF an FS; people might be thinking FSR with your FS, causing confusion.
#21
Thread Starter
RE: OS .60 SR muffler
ORIGINAL: TFF
You have a small nomenclature problem you need a muffler for a FSR/SR. Your calling your SF an FS; people might be thinking FSR with your FS, causing confusion.
You have a small nomenclature problem you need a muffler for a FSR/SR. Your calling your SF an FS; people might be thinking FSR with your FS, causing confusion.
TFF, Thank you for bringing that to my attention. I try to proof read everything, but missed that. Corrections made.
Frank