Jb31961

Are the bearings in four strokes more susceptable to rust that 2 strokes? Should I run the engine dry of fuel at the end of the flying day and put after run oil in the engine each time it is stored for a week or so. If so, how much and what brand?

Thanks!

jeffie8696

Yes very much so, it seems that moisture is trapped in the crankcase and the bearings as well as cam and lifters rust up something fierce. Take as much preventative maintenance as you can. I even remove the cam cover and valve cover and pour after run oil in them if the engine is to sit for more than a month or so.

captinjohn

+1

the pope

Heres my secret recipe so dont tell anyone ! 1/3 auto trans fluid , 1/3 kero and 1/3 synthetic oil . Run dry and add this mix and you're good to go and if someone doesnt like my mix bite your lip . Cheers the pope

Rudolph Hart

Ok lip well bitten!

Jb the nitro in glo fuel likes attracting water (whether you run the engine 'dry' or not,makes no difference) and will suck outside moisture into your engine crankcase where the main bearings are.On saito fourstrokes after flying you can leave them as is for up to about four days with no restart engine wise.After that period if you don't run the engine or run oil thru the engine sooner rather than later you will start to loose bearings,there's an easy check you can do if you are worried about the one's you have.I put an oz of atf in the crankcase and hit the prop with a starter for about ten seconds.Keeps the bearings like brand new,easy.

Hobbsy

My Feedback: (102)

I have never blended any ARO but have used Corrosion X and now use NAPA Fogging oil. I like the aerosol cans because when you apply it, the oil foams up inside the engine and gets everywhere, it even comes out through the front bearing.

blw

My Feedback: (3)

Getting something, almost anything everywhere in the engine is 99% of the prevention. Think about it. The foaming action is flushing and cleaning everything. Some oil is coating the steel parts. I never thought I was getting close to everything oiled properly when I used ARO.

I think flushing an engine with either kerosene or gasoline and hitting it with a starter is the first step in preserving an engine for the long term. Drain it all out. Then, making sure a foaming lubricant like Hobbsy mentions is used to finish the job.

1QwkSport2.5r

Since I'm of an eccentric type of mentality, I use a certain fuel with a certain oil "package" and have not found any need for using any extra after run regimens though I will oil an engine up pretty good if it's getting stored for a long time. The last time I pulled the cam box off one of my 4-strokes, oil came pouring out of the cover. I had to wipe the table off with a methanol soaked rag twice to get all of the oil off the table I didn't expect to find. If one uses more than 10% nitro in their fuel then I'd be more concerned. I think high quality oil of a reasonable content (20%) should be enough to protect an engine between runs.

Granpooba

My Feedback: (5)

" Marvel Mystere Oil "

Works great in ALL gas engines.

Hobbsy

My Feedback: (102)

1Q I wonder if your fuel and mine are the same. MIne is WildCat with 18% blend lube. I've never had a Saito bearing go bad, I've bought a couple of used ones with bad bearings.

1QwkSport2.5r

Doubt it. 5-10% nitro 20% castor made fresh in my basement. I also make and use 5% nitro 25% castor in my bushed engines, 30% nitro 8% oil in cars, and 80/20 FAI fuel from time to time. See the trend here?

johnboy151a

My Feedback: (68)

The two cents from the peanut gallery... I put Mystery Oil, or a synthetic ATF in the crank case after every day of operation and try and store the ACFT with the nose down. Changing the front bearing is not the hardest thing to do, but a syringe full of oil can prevent it for a very long time.

John

1QwkSport2.5r

When I do pickle an engine (which is rare) I completely fill the inside of the engine with oil and drain it out. Install into a ziploc Baggie and away I go. I use a concoction of mineral ATF, and the snake oil is Seafoam motor tune. It's about a 95/5 mixture. Glow plugs don't like ATF much though I've found.

johnboy151a

My Feedback: (68)

I didn't know that about ATF and Glow Plugs. Thanks!

John

Hobbsy

My Feedback: (102)

1Q, You're a regfular Micro Brewer, don't let Pete hear about that.
For several years I had some RCV engines here and their fuel recommendation was WildCat 10% fuel with 16% 80/20 blend. I ran some the 16% in Saitos, Lasers and Enyas without incident

1QwkSport2.5r

Who's Pete? I'll watch my back..

I must be so far out in left field.... Haha.

blw

My Feedback: (3)

I'm becoming convinced that rust is sometimes a random occurrence, and that there is no obvious reason for some engines that never rust or for those that rust easily. If you look at all the reports of rust vs no rust you see that it becomes illogical regardless of how an engine is treated, fuel used, or weather conditions.

Sport_Pilot

The alcohol does this, not the nitro. Methanol is also corrosive to aluminum, nitro is not. However, nitro will leave nitric acid when burned but almost all of that is consumed by the burning methanol.

rcmichael

My Feedback: (21)

I have used Marvel air tool oil for years. Never had any bearing issues at all. It is great in all 4 stroke engines EXCEPT ys due to the pump system that doesn't like petroleum products. Try it you won't be disappointed.

airega1

My Feedback: (204)

Whatever you do DON'T use petroleum after run oil in a YS

airraptor

My Feedback: (66)

I know people swear by after run oil but to me its just a gimmick. I have been flying since 78 and I never used after run oil. I opened up the back of a webra 120 that had set for 10 years. It was in a crash and I didnt run the fuel out or add oil to it. just how it was with dirt and all. There was still oil, although thick, in the bottom of crankcase. bearings looked good.

Now I will say that something has changed with the fuel or the bears in most engines of today. they do not last as long as they used to. OS engines are the worst for these. when they switch MFG for their bearings they went south with them. Sure they may say japan on them but not the same.

I dont run my YS engines out either but that might bite me one day lol.

the pope

My experience is that the asp bearings are the worst then saito , OS in that order and I think that bearings will go eventually and that aro doesnt hurt . Cheers the pope

a70eliminator

Rust, corrosion, oxidation, one motor vs another some guys have no issues others do, I for one have cracked open crankcases and found rust. I live in the rust belt usa and depending on the season have had tools rust up overnight in my garage, the basement of my house is terrible.
Just making a point that geographical location is IMO has the largest impact, I have a never ending all-season battle with rust and corrosion, ATF, Sea Foam, 30W, whatever I have handy goes down the pipe.

speedracerntrixie

My Feedback: (29)

I think this has to do with location more then anything. Just a side note, if you use any after run with pertrolium in a YS you will be buying regulator parts.

Rudolph Hart

Thanks it has been interesting reading.Maybe living 150 mtrs from the beach has it's drawbacks,onshore winds most times,and we sure do get a lot of rust here.

ps tim you make your own dynamite?? that sounds interesting.

pps hobbsy can always say 'hey i warned ya'