Adding after run to new style 4 strokes
 

Ok, I used to add through the crank vent, would like to here how others are adding after run oil to the new OS engines.

RE: Adding after run to new style 4 strokes
 

I just replaced bearings on a Mag 91 four stroke. I had about 6 gallons of fuel through it over a two year period and three really hard crashes and the nose bearing was a little rough.

When I tore it down, there was no rust, just some baked on red from the fuel. The wrist pin pulled right out. No indication of any rust. I ran Omega 15% in it and never ran it dry at the end of the day, and never used any after run oil. I also never pumped the tank dry, but just pluged both lines. It was almost a year after it last crash before I finally tore it down, so if it was going to rust, it would have by then.

I think a lot of guys confuse the red baked oil for rust. It isn't. Rub your finger across it and if your finger turns up red, it may be rust. It it comes off clean, it baked on red dye from the fuel.

I use after run, but only on a rebuild, to make sure things have a bit of inital lube on their first run.

I think you can love an engine to death. They don't require a lot of fussing, just try to keep them clean and run good fuel and they will last a long time with no problems.

RE: Adding after run to new style 4 strokes
 

Had the same experience with no rust.

But I've had them rust at times also. Particularly to run them dry wide open throttle and hot with no after run oil.

RE: Adding after run to new style 4 strokes
 

I'm not surprised that someone from California would be puzzled by other folks needing after run oil. Believe me, where you live can make a huge difference in whether something rusts easily or not.


Ed Cregger

RE: Adding after run to new style 4 strokes
 

I used generous amounts of after run every day on my engine. Bearing's rusted, con rod is rusted to wrist pin...

RE: Adding after run to new style 4 strokes
 

Wrist pin rusted to de kneebone..very funny mate.I've never used after run yet tho i've only had the engines twelve months and we have a relatively dry climate.

RE: Adding after run to new style 4 strokes
 

Ed, I know what you mean about rust and where you live. I'm orginally from Mich and did a few years in mid state N.Y. also. However, where I live and more importat where I fly is heavly influnced by the Ocean Marine layers. For most of the year, our flying is limited in the morning due to the fog layer. It usually burns off aroun 9am, we are not imune from moisture. In addition to the fog. some of the guys who live closer to the ocean have a rust issue due to salt in the air. I bought a pattern plane from one of the retired from flying guys and he had it hanging in his garage. He just lives about two blocks from the beach. All the pushrods, clevises, and landing gear was rusted. There was no engine, so I can't tell how that held up. I live near the only( I think) beach that you can drive on. The truchk that are local and are on the beach stand out like a sore thumb, the look like they lived in Michigan over several winters, big rust holes.

I'm not sure if any of this has much to do with engines rusting or not though.

Don

RE: Adding after run to new style 4 strokes
 

I have never used after run oil and never intend to. I live about 5 miles from Tampa Bay a very humid area. Never have any rust and many engines lie idle for years at times. Also never run the engine dry, just drain fuel from tank take it home. just lazy I guess but don't have engine problems. Why I don't know, but guess lazy, lucky? Been doing it that way for at least 50 years. Have had I guess almost every engine made from T D's to Saito 4 strokes and Sachs gassers. Suit yourself.

RE: Adding after run to new style 4 strokes
 

Luck is the best preventive for most any problem. A bit of castor in the fuel also helps for those of us who sometimes run short of luck with rust.

jess

RE: Adding after run to new style 4 strokes
 

The Alpha series OS four stroke engines have plated cranks, cams, and rings. There should be little left to corrode. I like to run the engine WOT for a bit to get things hot, cut it to a high idle for a while to let the oil system do it's job of venting the crankcase and cut off the fuel to run it dry. This is with an FS-52 I added the oiling system to. I've been running home brew methanol or E85 with Klotz Original Techniplate. I got a used FSa-81 second hand that smelled of fuel when I pooped the backplate off, but the bearings and parts where clean.

RE: Adding after run to new style 4 strokes
 

>> This is with an FS-52 I added the oiling system to >>

Hi Greg, do you mean you modified an older OS with the tiny hole in the head so oil would circulate like in the new Alpha series engines?

Thank you,

Ernie

RE: Adding after run to new style 4 strokes
 

Yes. Have a look. www.dieselrc.com/project1.html