Bax, I have an FL-70 side mounted in a GP Cessna 182 turning a 12x6 Master Airscrew 3-blade prop and burning Powermaster 15% Nitro/ 18% Castor&Synthetic. I ran the engine in on a stand with the fuel mentioned before and a Top Flite 13x6 prop turning 9800 rpm at full throttle. I had no problems on the bench, but I have not ran it in the plane sideways yet. I noticed that with the breather nipple connected to the muffler I got allot of oil gushing out around the breather nipple. I read in a couple of posts about people disconnecting breather from the muffler and allowing it to vent out the bottom like normal. Will this cause any damage to the engine. I also have read about premature wear in the valve train/camshaft. I am reading about people removing the seals on the rear bearing to help lubricate the engine. Is this advisable or will it void the warranty (which sounds like OS isn't honoring)? Should I be concerned? I was influenced to buy this engine after reading the reviews in RCM/MAN; and I am starting to feel like I should have bought the Surpass II the more I read about the engine on RCU.

All my engines are OS and up until now I have been a die-hard OS fan.

Looking forward to your reply. Gene

I have only run one 400cc tank through my engine at the moment, and mine seems to get plenty of lube in the cylinder head. I have set mine up as stated in the instructions.......lets see how it holds up

We'd consider a 12 x 6 3-blade prop rather large for your engine. That prop's more suited to be run on a .91-size 4-stroke engine.

With a good-quality fuel, we've not seen any particular problems when the fuel/exhaust system's connected per the instructions. We would, though, recommend a fuel with castor oil in the mix because the engine's non-ringed.

We have no problems honoring the warranty. The difficulty comes when people think the warranty covers ALL problems. It only covers actual defects in parts and workmanship of the original manufacture. Not everything that happens to the engine, whether accidental or not.

Bax, I wasn't speaking from experience about warranty issues as I have never had any problems with any of my engines (they are all OS). I guess reading too much can be a bad thing sometimes. I was reading complaints about the FL-70 engine on this site and I got a little concerned is all.

You say the 12x6 3-blade prop is two big? I was using a suggested 13x6 2-blade which is within the suggested range and went by the recommended -1" from the diameter or pitch for a 3-blade. Maybe a 11x6 3-blade then? This will be my first 3-blade so I am not quite sure about picking a size. I am not looking for high performance, but just a more scale look for my Cessna.

Is the PowerMaster fuel I am using, 15% nitro & 18% castor/synthetic blend; a good quality fuel to use? This is my first 4-stroke and I don't want to ruin it for sure.

I wasn't trying to make accusations, I was just concerned with the things I was reading about the engine including people calling it junk.

Thanks for the help. Gene

Well, we'd prop the engine to turn about 10,000 RPM on the ground when leaned to just rich of peak RPM. If the prop will let the engine run at that RPM, then it should be OK. You can even get into the low-11,000's with no problems. Don't run the engine too rich. It's not really good for it. The non-ringed engines "like" to run a tad hotter than the ringed engines.

Your fuel should be OK.

I just completed my GSP Cessna with FL-70

I hope it doesn`t wear out as quick as I have read about the others here in the forum.

I was interested in your FL 70 problems as I ran into difficulties after less than 8 flights and a run-in period. A colleague pointed out whilst spinning the prop that there was a tendency for the prop to slop either side whilst at compression. This he suggested was possibly premature wear on the connector arm and the crank pin. The bushing is brass so itis the softer metal. The engine went back in the box and was send off for warranty repairs. I was informed that the cause was looseness between the piston and the cylinderliner. Thepiston was able to pass the top of the liner and lock at compression causing a 'bounce' effect. This I was told was not a warranty item and would cost 75 dollars to repair after discount because the warranty was in force. This was staggering as the OS fame has promised years of faithful service not an engine rebuild inside a gallon's use of glow fuel (15% Nitro and 17% oil mix)
The warranty was refused and there's no point in complaining and the fact that the engine had clearly failed on the 'business end' which is where the wear is going to be, did not matter
as it seems they only guarantee the bits that arn't going to wear. Beware! my friends of the OS warranty - the rules are non negotiable. Maybe the reason why they have discontinued that ringless engine is that they have had complaints of premature wear.