trdexter

I have a OS 61 FS and I'm wondering why there is nipple threaded in the back of the engine on the back plate. This one runs with a strait header pipe with no muffler, do I need to plug the vent line from the fuel tank in the nipple thats on the back plate or what.

bob_nj

My Feedback: (62)

I'm guessing that the engine is used.
Did this setup come with a plane that you bought?

The fitting you describe usually drives a fuel pump or regulator of some sort.
For instance, all of my glow two strokes use a fuel regulator ( Cline ) which is driven
from a fitting on the backplate like you have.

Not sure what you mean by, "strait header pipe with no muffler" though?
Can you post a picture?

trdexter

It has a header pipe only and yes it's used I think it came out in 1983, these did not have mufflers and I thinking maybe the tank line to pressurize the tank went to nipple on the back plate but also I've heard that 4 strokes do not need to have the tank pressuriezed.

bob_nj

My Feedback: (62)

My fault.

When you said "FS", I thought it was a model designation.
Actually you meant that it is a four stroke!
I think there was an OS 61FS at one time.

The nipple is just a crank case vent. Don't hook it to your tank at all.
Just run it out the bottom of the plane.

My limited experience with four strokes is that some like to be pressurized by the muffler, and some don't_bob

trdexter

Do I do the same with the vent line for the fuel tank ? Just leave it unhooked and hanging out the bottom of the plane.

bob_nj

My Feedback: (62)

Usually the vent line is either hooked to the muffler, or just hanging near the muffler if it needs to be hooked up.

What is your tank setup_bob

trdexter

I am not sure what to do ??? I bought a built Midwest Cherokee with a 62" wing span and the fuel tank has a fuel line for the carb and vent line comming out of it and I'm trying to figure out a way to install the 61 4 stroke.

The Ghost

Its just a crankcase vent. Just run it outside the cowl and don't worry. It's so the crankcase can breath and alloy excess oil to vent.

Cheers

bob_nj

My Feedback: (62)

Check around to see if that is enough engine for that plane.

What is the plane supposed to weigh ready to fly?

bob_nj

My Feedback: (62)

I can't find a website for Midwest.

trdexter

Not possitive its a older kit from midwest and I can not find any thing on there sight.

bob_nj

My Feedback: (62)

Check around for a similar sized plane and see if that looks like the right sized motor.

It's late and I can't think right I guess [:-]

trdexter

okay

MinnFlyer

My Feedback: (4)

That's a good little engine. It was my first 4-stroke. The Ghost is correct, just run a piece of fuel line from the rear nipple out the bottom of the cowl. Leave the vent from the tank open, you don't need to pressurize.

trdexter

Thanks folks

redfox435cat

it's a vent line. run it out the bottum of the cowl. Your going to have to tap the muffler with a nipple if you don't have one and use it to pressurise the tank. You can try running without it but your taking a big risk.

red head

Like they said on the vents!!
But on another question: that plane was designed for a 40 2 s and it flew pretty scale on that eng. I had a 46 in mine and that was more then enough. A 60 4s will be plenty. If I decide to fly mine again it will have a 52, 4 s in it. And it will fly again.
That plane has been out of production for a good while and probably not listed any where. The Midwest web site is midwestproducts.com and their ph# is 1 800 348 3497. ENJOY !!! RED