Two O.S. 61 FX Engines Went Bad On The Same Day!
06-10-2012, 09:01 AM
Two O.S. 61 FX Engines Went Bad On The Same Day!
Iown two O.S. 61 FXEngines. They are identical in every way except for age. In both engines the same O-ring went bad. One of the two engines is only a year old. What I can't figure out is what caused both of these Engines O-rings to fail. I've been a proud owner of O.S. Engines ever since 1996, and have never had an O-ring to fail. I own an O.S. 40 SF Max Engine, and it still runs fine. The O-rings go on the Needle Holder. http://www3.towerhobbies.com/cgi-bin...&I=LXCR36&P=PU
Additional Information:
The flying season just started for me. I've been taking my airplanes out of storage, and checking them over. The other day, Itook one airplane out and started the engine. Idid some run tests. Checked the high speed needle valve, and the idle. Everything seemed to be running right. The next day, Itook the same plane out for my first flight of the season. Iflew for about 10 minutes, and brought the plane down for a landing. On the first landing approach the Engine stopped. After retrieving the airplane, Idid some more engine tests. Ifound that the Engine died shortly after Idling it. After Itried to readjust the Carburetor, and couldn't solve the issue, Itried other glow plugs etc. Finally Iended up taking the engine out of the airplane and taking the Carburetor apart. That is when Idiscovered the bad O-ring. It appeared that a part of it just broke off. Itook the Needle Holder and Needle out my old engine, and put it on the new one. Iput theengine back on the airplane started testing it. Once again it was giving me the same problems. Finally Itook that Engine out the airplane, and got my old engine and put it on the same plane. Iput the needle valve etc back into the old engine, and this time Icouldn't even get the thing to run. At this point Istarted to wonder about the tank. I did another tank test, and found no leaks. I finally took the Engine back off the plane and took it's carburetor etc apart. Inoticed that the same O-ring went bad.
06-10-2012, 09:45 AM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
Can the fuel around the o-ring seize the o-ring over winter storage? If so, might a movement of the high speed needle "tear" the o-ring causing an air leak?
I have several that haven't been worked out this year. However, I store my planes in a "nose up" attitude - maybe draining any fuel back into the tank.
06-10-2012, 10:43 AM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
Just thinking out loud ...
Can the fuel around the o-ring seize the o-ring over winter storage? If so, might a movement of the high speed needle ''tear'' the o-ring causing an air leak?
I have several that haven't been worked out this year. However, I store my planes in a ''nose up'' attitude - maybe draining any fuel back into the tank.
Don't be afraid to check things out at the beginning of the season and replace a few of the cheap parts. OS sells O-rings and gasket sets too.
06-10-2012, 12:12 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
Just thinking out loud ...
Can the fuel around the o-ring seize the o-ring over winter storage? If so, might a movement of the high speed needle ''tear'' the o-ring causing an air leak?
I have several that haven't been worked out this year. However, I store my planes in a ''nose up'' attitude - maybe draining any fuel back into the tank.
Don't be afraid to check things out at the beginning of the season and replace a few of the cheap parts. OS sells O-rings and gasket sets too.
I Always put air tool oil in my Engines and store them nose down. That way the oil runs into and out the bearing. I use air tool oil because Harry Higley recommends it in his book “All About Engines”. http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXL802
This is the first time I have ever had to replace a part on one of my Engines. Is it cheaper to buy the O-ring and Gasket Set? I would have considered buying them that way if I would have seen it sold that way on towerhobbies.com. Can you buy them as a set from towerhobbies or do you haft to go straight through O.S.?
06-10-2012, 04:58 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
06-10-2012, 05:57 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
06-10-2012, 08:18 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
06-11-2012, 06:34 AM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
It can happen. If you are running the engine with long extension wires on the needel valve they will vibrate and kill the O-ring on the NV faster then normal too.
This does not occur as it may have in the past with the OS AX series engines which all now come with that wonderful new carb and the severe slant to the rear needle and a cool three and a half inch cable flex extension.
This works so well that I leave them all full length needed or not and its even safer than the rear needle types.
Just a thought, notice the long stock OS extensions:
John
06-11-2012, 11:08 AM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
Gray Beard - Thank you for your information.
I posted a question to Bill.
06-11-2012, 11:29 AM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
This begs the question and forgive me but it must be asked as this would be most unusual since I have around six .61 FX's for some years now I have never even had occassion to remove the needle seat:
Did this occur all on its own or did this happen when you pulled the seat and disturbed the O ring.
John
06-11-2012, 01:22 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
Gregoryshock you said in another post somewhere that the O ring in partucular "became embrittled and broke" and that it was only a year old on one of the engines.
This begs the question and forgive me but it must be asked as this would be most unusual since I have around six .61 FX's for some years now I have never even had occassion to remove the needle seat:
Did this occur all on its own or did this happen when you pulled the seat and disturbed the O ring.
John
John, O.S. Made that part removable so that you can change the needle valve from Horizontal to Vertical. My 2 O.S. Engines came with the needles in the Vertical position, and Ihad to put them in the Horizontal position. This is so that the Engines could fit onto my models. Fast Forward to now, the only reason the needle valve holder was removed, was because the engine wasn't running right. Ifelt that I had to remove this part for cleaning. Ithink it might be possible to clean things up without removing this part. Ithink since O.S. Made this part changeable on purpose, simply removing this and putting it back in should not tear an O-Ring.
06-12-2012, 12:09 AM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
Has putting a 'new' O ring in the needle seat cured your running problems?
John
06-14-2012, 01:56 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
Some here might call me cheap for saying this. But I think after you figure in the shipping cost they are expensive, and I hope I never haft to replace them again.
Most hardware stores have huge assortments of O-rings. They're dirt cheap compared to the ones sold as replacement parts for anything. Take your new expensive ones to the hardware and compare. You may have to buy a pack of 4, but trust me, they'll be cheaper than the one you get shipped from Tower.
A year or so I had a similar failure and took the carb to the hardware store and found the ring that fit. Think it was 4/$3.50 or somesuch.
06-16-2012, 02:00 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
The Ace Hardware near my house had a box of very small rings, iirc. The Lowes closest to the house has a wall back in plumbing with them in small plastic bags. I think Ace had more in 1/10 the area.
06-18-2012, 02:44 PM
RE: Two O.S. 61 FX Engines Went Bad On The Same Day!
