cappaj1

My Feedback: (1)

I sent back an OS Max 46 AX to Hobby Services yesterday. I'll be waiting until next weekend at the earliest to fly and I'm a newbie who just recently solo'd so I'm eager to get back in the sky but only have that single trainer with the engine I sent back.

I have an old OS Max 40SR Schnuerlye Ported engine that's been sitting for 34 years, after only a break-in and single flight.

I'd love to get it running for my trainer while I'm waiting for resolution on my 46AX. I need help though. I've never disassembled an engine. It wouldn't turn over by hand at first, the throttle would barely move and the hi speed needle seemed frozen. With alot of torque applied, I got it to turn over but there was just a constant resistance, no compression increase or exhaust decrease.

So I pulled the carb, muffler, head and crankcase backplate (which had a paper gasket in it which I re-used as best I could) , took the below photos, and then immersed all the parts in antifreeze.

Then, while immersed, I turned the engine over and slowly it loosened itself up so I got a compression and exhaust stroke feel. I reassembled everything. I also got the throttle to move easily, but the hi speed needle. even though I completely removed it and applied antifreeze, is still stiff when turned almost all the way in. I don't even know if I'm getting it to full clockwise/closed and it just gets real tight.

I need suggestions on what to do next, please! I plan on lubricating everything as best I can with some 3 in 1 oil, and then putting in a new glow plug, installing it in my trainer and trying to fire it up? Does that sound good? Any other suggestions? Really appreciated. Thanks.

TedMo

If it were mine I would spray it liberally with WD40, reassemble, leave glow plug out, turn over several times with starter. put some fuel in carb, turn over some more without plug. Then put plug in and give it a try. It should run.

blvdbuzzard

Soak the carb in alcohol for a while to get the gunk out of it. I have also used carb cleaner, Berrymans, and the like in a spray can. Make sure they are clean, oil all moving parts, re-assemble, fuel and fire it up.



Dru.

downunder

Before you put that backplate on make sure the top of the rod slides easily along the wrist pin, not that it can move much but it has to move a little. If this is gummed up then the rod will rotate the wrist pin in the piston which isn't good. For the broken gasket you can either cut one out of paper or use a very thin film of silicone sealer but let it dry until it goes rubbery.

capt17

What all these guys said sounds right. I revived an OS 40fp that was 15 years old with no difficulty in the same manner.

abacro

Ok,first off,that engine is a OS Max FSR. It only says SR on the exhaust side of the crank case,it has a ring on the piston,and 2 ball bearrings on the front housing under the carb.Your high needle is turning hard due to the small rubber oil ring on the needle having been exspanded. Replace it and your high needle should be fine. On the low needle side,screw it all the way in and back it out 4 turns for the starting point for adjustment.High needle will normally run at 1.5 to 1 turns open from fully closed. The FSR series of OS engines are very very fine running motors and last for years! I know this because i have 3 of the 40 FSR's identical to this one and use them constantly. The gasket on the rear plate can be made from any piece of manilla paper or paper like that.Compression on the 40s i have has never been realy strong,but then again they turn really high rpm's in the air for flying.Mine all turn a 10/6 master air screw prop at over 17,000 rpm's on the ground running 15% nitro! The muffler for the FSR series engines is in fact a manufacturer TUNNED PIPE! In all my years running my FSR's my only problem with any of them was the muffler mounting bolt holes in the case. In any kind of a crash,they's break out from the case. But then,your not supposed to crash either! lol My Glow plug of choice for my engines is the Fox RC long,Idle bar plug. I know,everyone will say use the OS # 8,but they cost to much to burn up on 1 run! And yes the FSR's will eat glow plugs till they find one they like! I've gone through a whole card of plugs to find 1 that the engine liked and am still running the same plug after 7 years of flying the engines. ( come to think about it,i havent changed a plug in any of my FSR's in over 7 years) As to the power of the 40FSR's my first one is still in and flying my 11.5 pound Dirty Birdi 40 with authority,and shows no signs of slowing down. Another bit of info if you please is ,do not run pressure on the 40! All of mine run with out the muffler pressure line hooked up. I hold the plane at a 45 degree angle and tune the high needle for max rpm,and then back off 1 click on the needle and go fly. You'll hear the rpm's of the engine increase dramatically in the air after the first turn,due to the fact that the engine is as others put it,( comming up on the pipe!) A.K.A. the muffler. This is just my own opinion here,but i have yet to find any new 40,46,or 50 even that seams to have the same power as any of my 40fsr's. When the 40 FSr's were first introduced back in the 70's,they were touted as having more HP then any 60 on the market at the time,and i for one believe it!

well hope this info help's you out!

Art

oh one last thing,check the state of the bearrins in the motor,they'll probly need replaced!

brett65

My Feedback: (18)

Make sure the crank turns smoothly, use a new plug, and you may not need a paper gasket, but you can use automotive silicon if you want. The nitro car guys do it all the time.

cappaj1

My Feedback: (1)

Well, I got the engine in the LT-40 today and fired it up! It wouldn't run smoothly though when transitioning from low to high throttle settings. I have to try again tomorrow with the low speeed needle adjusted per abacro's suggestion. I needed to take the airplane home as with an empty tank I checked the CG and it was tail heavy. This engine is lighter than the 46AX so I have to add some lead weights to the front of the airplane to balance it. I also bought some foam to wrap the tank completely in it as it was suggested by someone at the club who thought I might be getting foaming of the fuel.

abacro, question: When you say not to use the muffler pressure line, what do I do with it, plug it and just let it dangle in the firewall?

Thanks.

Mr Cox

You'll still need an opening for the tank to let air in as the fuel is used up. Just mount the tube facing into the wind.

For loosing up old engines I've used fuel, nitro is a good solvent. Only real danger/problem I can see is the bearings as already mentioned above, check for rust...

abacro

I let mine just hang out of the plane,do not plug it as it is the tanks only vent line on a 2 line set up. To adjust the low end correctly just do this, Leave glow plug igniter on engine and adjust it with the igniter on.Set it so you have good idle and smooth transition to full power. When the igniter is removed,the engine will start to load up a bit,just hold the plane and give full power to clean it out. When tunned properly,the motor will take a minute or so to idle down in the air. Sounds about like a dirt bike when you throttle off! This should help you out now!

good flying,

Art

BobHans

Abacro - thanks so much for taking the time to share your experience. I just was given a 40 FSR invery good condition and had no idea what I had. Your post will be enormously useful !! I'm putting it in an Ultra Stick 40.

cappaj1

My Feedback: (1)

I see this thread popped back up recently and realized I never updated it.

I did replace both bearings and the ring in the engine and it seems to run fine.

Here's a video of the engine after the new bearings and ring on the test stand

http://www.youtube.com/watch?v=KN5JXmEzHd8

Jetdesign

My Feedback: (8)

Awesome! Glad to hear it Cappa...

Edit: Geez, you make the BEST videos!!!

JollyPopper

My Feedback: (6)

I have read some posts in the past in RCU in which folks were making a case for the FSR series of OS engines being the best engines ever produced. I was interested in that because I have a .60 FSR that I bought new in l974. It is an amazing power house. It produces a lower, throatier exhaust note than most and is really torquey (is that a word?). It doesn't sound like it's turning a lot of RPM (don't recall that I ever put a tach on it as I am not much impressed by numbers), but it certainly does the job. If they are not the best engines ever produced, they must be among the top handful.

Spacemonkey71

Well, my "little engine that could" isn't QUITE 34 yrs old, but it WAS discontinued in 1982 (so it's only 26 years old). It's an OSMAX .28 (originally for a heli/ but I put an airplane prop and muffler on it and ZOOM!!!!!!!!!! off it goes!!!!). Another engine that's old as the hills is my K&B .45 which is the SWEETEST sounding engine I've got and I doesn't even stutter when you cut the throttle for landings!

I love old engines I like the way they sound, the way they act, the way they look, and I like saying, "Thanks for the compliments on flying! This engine is almost 30 years old!"

Another old engine I have is a Webra 10ccm (.61 ci) it's probably CLOSE to 34 years old and it pulls like a FREAKING OX ON STEROIDS!!!!!!!!!! I can't even run that engine past 3/4 throttle b/c I'm scared the plane will pull itself apart!!!!

FlyerInOKC

My Feedback: (6)

Remove any non metal parts and bake it at 250 to loosen any built up castor oil in it then mount it on the stand and run it until the tank goes dry. Follow up with a few drops after run oil or Marvel Mystery oil for air tools and flip the prop a few times to get into the bearing areas.

Gray Beard

My Feedback: (-1)

Well, the post is from 08 but the same question has been asked over and over for ever. If you have a covering heat gun then just heat the engines up and then roll it over by hand and get the carb to carberate and do as flyer said, just fire it up. They will usually start right up and the heat and exhaust will take care of the nasty old castor. I still like to open them up and check out bearings if the engine has them.

FlyerInOKC

My Feedback: (6)

Yeah I forgot to look at the date my CRS kicked in.

Gray Beard

My Feedback: (-1)

Doesn't mater, it's an age old question, sort of like what size prop.

HighPlains

My Feedback: (1)

the real problem with gummy engines is the bearings. If the balls slide instead of rolling it puts flat spots on the balls. So heat the engine to about 250 in the oven before you turn it over and cleaner works well.

OzMo

My Feedback: (3)

I still use an OS 40 FSR ABC. I did replace the bearings. it was easy enough. Here is a nice you tube on rebuild a glow engine.
https://www.youtube.com/watch?v=IUD_UBjxkYQ

Gray Beard

My Feedback: (-1)

Kind of an up date. I had a new in box Fox .40 I have been saving for just the right plane, it finally happened this year. The engine had never been started and was free spinning, all looked good but I could see the 20 year old grease used when the engine was boxed was hardened, I cleaned it out a bit and decided to just fire it up and see what happened. It started right up but quit as soon as the prime was burnt off. The fuel wasn't flowing through the carb. I pulled the high end needle and flushed it, that was flowing good. The low end needle was frozen in tight so I knew where the problem was. I pulled the engine and took it apart then soaked it completely in a tub of fuel for two days. That loosened up all the grease and I cleaned everything by hand. When I tried to flush the needles the low end was still full of crud. I had to use a pin first to break it out then a round tooth pick then I was able to pressure flush it. That did the trick and now the fuel is flowing very well.
Just a minor thing and I knew I would have a little trouble but it was worth a shot to try to fire it up before a total break down.
Gunk Happens!!!!

FlyerInOKC

My Feedback: (6)

I have an old NIB Enya 4 cycle II .46 (with muffler) I have reserved for a Dornier D-1 if I ever finish it! Any recommendations on the care and feeding this engine?

Gray Beard

My Feedback: (-1)

Not really, the Fox was in the box from about 89. I usually use my squeeze bulb with glow fuel in it and pull the needles then pressure flush the carb to make sure it is flowing. I just didn't do it this time. Doesn't hurt to open the back plate and soak them in a tub of fuel then clean them out. When I pulled the engine out of the fuel I heated it up with my heat gun and rolled it over by hand and cleaned the bearings and inside the case. With any new four stroke I always check the valves and make sure they are adjusted and working.
My kingdom for a small four stroke. I have been using them for decades but the smallest one I have had for myself was a .70. I think a four stroke in a small plane like the Up-Roar would be fun but I would build a Taylor Kraft or something around one.

FlyerInOKC

My Feedback: (6)

I lucked into the Enya 4 cycle, it had never had fuel in it. The previous owner was a guy with money to burn that got the bug bought everything in site and then went into something new a few years later. He sat on his stuff for the longest time then started liquidating a little at a time.