flyby50

Hello, i would like to know if the older OS- FS .61 4-stroke was a good engine, before the surpass, I did find info that it does not have the power that the surpass has, but i would like to know if it was a good running engine, and reliable, any info would help out alot, thanks,,, flyby50....

jaka

Hi!
All OS engines are good...or have been good! The first OS .60 with open valve gear was no power house (.60hp) but was dead reliable and could swing big props (14x6).
The more modern FS .61 had a little more power and was equally reliable.

w8ye

My Feedback: (16)

I rebuilt one of these 61s with new bearings and ring last year and to my surprise it was a well mannered engine. It seemed to have more power than a OS52 and less than a OS 70 which would be expected of the engine.

As Jan says, you have to be careful with comparing these. There is a 60 and a 61. They are both pre-Surpass. They are both well mannered but the 61 has power more in the realm of a Surpass engine.

F4U Corsair

My Feedback: (22)

I bought a used OS61FS this year, and it's a great, reliable engine. It's a great replacement for a 40-46 size 2 stroke. Lots of torque, if you want speed, stick with a 2 stroke. I tried it on an ACE 4-60 bipe and it flew it ok, but was underpowered. I moved it to a Sig 4* and I'm having a blast with it. They sound so cool! DG

flyby50

Thanks again Guys- for your help, I am now going four stroke crazy, one bad thing, its ready to snow here, w8ye- we should move!!!! [&o] flyby50

w8ye

My Feedback: (16)

Between you and I is the coldest part of the state. Looks like flying is over for me until spring?

Enjoy the four Strokes

phatom77

Dg
How is the 4-60 coming along? did you start on the uproar yet?


phatom

submikester

My Feedback: (6)

The FS61s are nice engines, I have had two - I did let them go however. They are reliable but far from powerful engines in my experience. They are also quite heavy for 61s, the case is about the size of the current generation OS 91 surpass, in fact when I was rebuilding one of mine I used the crank from a 91.

All in all, good engines - great for a trainer or something mild. They are too heavy for much else.

F4U Corsair

My Feedback: (22)

Phatom77, the 4-60 is about together again, all wood repaired and covered, just need to epoxy the wing support rods in and put a few bolts in. I rebuilt the ST S61K (new bearings and ring) that came off the Green AeroStik 60 and put it on. Just new a weighted prop spinner and I think it will balance out ok. The 2s is about 100g heavier than the 4s so that helps on the CG. I've got to beef up the 4* wing, and recover the fuse/wing first before I start on the Uproar, most likely won't start the it until after the Jan 1. Phatom77= BobM, from AirMasters?

rcoffsite

Does anyone know where I can get a pdf verion of the manual for the OS FS 61 Engine. My father gave me one but was missing and needs setup to factory specs.

MILDBILL-RCU

My Feedback: (6)

I have the manuals that came with mine. Give me a bit & I'll get them from storage & scan & send you them if youd like. let me know. Bill

ejmorgan

My Feedback: (1)

Here is a PDF copy of the O.S. FS-61 manual

rcoffsite

ejmorgan - Thank you.