fastplane

I have some Saito four stroke engines and would like to know what is best oil to use in the engine after running.
After flying I run any glow fuel out. I use only synthetic 20 - 30% glow fuel. Then when at home I put a lot of Marvel Air tool oil down the case vent hose to keep the bearings from corroding. After using this for seveal times and removing the back plate the bearings always have a resude on them that appears to be rust.
Is there a good quality 'white' oil that could be used that would provide corrosion protection and not discolor the bearings or other internals?

jay2000dakota

I use the same thing execpt I mix 50% Reslone in it. Do you run the engine dry at the end of the day? because raw fuel in the crankcase will cause rust.

Gray Beard

My Feedback: (-1)

Just for grins try a fuel with blended oil that has some castor in the blend then run the engine dry and forget the after run. Let it set for your normal time and open it up and take a look. A lot depends on the area you live in, humidity, but I never bother with after run and in both states I lived in I have never had a rust problem. Almost all my engines are four stroke and all I ever used was Power Master 15% with 18% blended oil. That was even used in my YS 1.40 engines. Today I have just started using the Wildcat 15% with 16% blended oil. The engines are all running fine and I'm having no rust problems. The little bit of castor helps with the rust problem. Here in Vegas we haven't got a humidity problem though. In Calif. we did have.

fastplane

Thanks for the response. I always run out the glow fue at the field and soon at home put lots of Marvel air tool oil in the crank case. I rotate the prop several times to coat all of the bearings. Still seems like the Marvel oil leaves a residue on the bearings and case I would like to eliminate. Looking for something that will protect from corrosion on the Texas gulf coast and not discolor or plate out on the bearings or case interior.

TedMo

Just call me lazy or lucky or whatever you want. Anyhow I've been using glow engines for many years,(at least 60) and never run them dry after use, never used after run oil of any kind, have never had to replace bearings and I have lived near the coast in Jersey and for past 24 years in Florida. What's the answer? I'm not recommending anything just making a statement.

Gray Beard

My Feedback: (-1)

A friend that moved from Vegas to Houston three years ago just sent me one of his OS .91Fs engines that he has had under his bench for two years. He has gone all electric, lucky me. When I opened it up there was no rust at all. I had to warm up the bearings with my heat gun to loosen up the castor gunk but other then that?? Just try a fuel with blended oil and forget the after run and see what you get. I do use mystery oil when I rebuild an engine to lube it up but other then that I'm just not a big fan of any after run oil. I have rebuilt several rust buckets from people that use it after each time they run there engines. Seems like that wee bit of castor in the blended fuels works a lot better then anything else I have seen. Odd thing is I'm not a big fan of castor either and I shudder when I see people adding more to there fuel!!! Yucky yucky engine snot!![:'(]

oldvet70

My Feedback: (10)

Dip it in the gulf. Some of that BP Louisiana light sweet crude should help.
Been running model engines for 50 years. ARO is cheap insurance. Try some Castrol Syn tec. Works great and never gums up.

fastplane

Gray beard, thanks for the note. I never use after run oil in my four strokes. I only run fuel out when at the field. After arriving home I pour Marvel Air Tool oil into the case by using the case vent hole. I rotate the crankshaft severl times to distribute the oil into the bearings.
So, I am quite disappointed in the deposits on the bearings after several flights. I am thinking the Marvel oil is leaving deposits. That is why I am looking for a really good 'white' oil the will not discolor and or leave deposits while setting in the garage. One thing nobody has mentioned is how do they tune the Saito 4 strokes. If you peak out the RPM while tied up , how much do you back off RPM to get acceptable amount of oil to the engine bearings when in the air? Considering the prop unloading at higher speed.

ARUP

I use air tool oil. Never had any rust problem to date.

Gray Beard

My Feedback: (-1)

Same as any other engine, get it to the max RPM then back off the needle until the RPMs drop 3 to 500. Where we live I tend to fatten them up about 500 +or- a few. I fly the plane then decide if it should be adjusted a little more. Once I get them set I don't fiddle with the needles unless I change prop size or when the weather starts to change. Right now my engines are tuned for 100+ degrees but as winter sets in they will slowly get fattened up a click at a time. I average about 4 clicks fatter in the winter. People forget how cold it gets in the desert but the engines know all about it. Seeing tourists come here in shorts at Xmas time then swearing about how cold it is is always funny.