I have always heard the same - each specific use/machine has different running conditions and tolerances.
Motorcycle oils are formulated to run motorcycles and the conditions they operate under.
Just think about what the different conditions are that each of these very different machines operate in.

Motorcycle VS. Airplane...

First thing that comes to my mind is no stop and go in the sky... and altitude.
As you go up in altitude you go down in air pressure and everything that goes along with that.

I take the guess work out - I do the idiot proof shi^ when ever possible... I buy the oil with the motorcycle on the front.... I know the temps in my area are 60-90 degrees F, and get the 50w.
I buy the easiest to find - sold in Wally world - auto stores. If I can get the miles out of my bike that some of the others have I'll be tickled pink. If not MOCO has a factory rebuild service that sounds like the way to go. So far my bike leaks more than it uses and I'm ok with that for now.

smart decision, I am also a licensed FAA aircraft mechcanic, on another site I think it was the AHDRA site one person had free availabilty to a drum of shell aero, he brought it up on the site for using it in a race bike, fuel bike I think. One of the people that answered was an aircraft mechanic and he gave an explantion why not to use it and his facts were real. On your oil leaks stop by my house and throw2 it on my lift and they will go away. Even my stroked 69 sporster did not leak, and that was after 25 years that I owned it, and I did't have a lift back then just a wood milk crate
Deerslayer

I cannot speak on airplane oil but I can speak on airplane primer...the stuff is slicker then snot...meaning its a good paint job primer to start with.

That would be a back saver... Thank you for the gracious offer!!
And IF I'm ever out your way I will take you up on it.

The tranny leaks out of the seal on the pully output shaft. Seems I'd have to pull the primary to get to it.
The Top end of the back jug is seeping.
The base of both jugs where they sit on the case are seeping.
When I park I get a couple drops from under the tranny leak and a couple drops from under the engine.

I took it in to the dealer with 9500 miles on it for a new back tire. Never leaked a drop before that. After the tire was put on the next morning there was oil under it and it's been like that since...
The main reason I do all my own work.
I'm also a very firm believer of don't fix it unless it is broken. Since it still works - and the worst thing is I CHECK the oil more frequently.
I'd have to pull the tanks off to get to the fasteners that keep everything tight for the engine.
Seems like a lot of work just to keep a couple of drops of oil off the ground. The engine seems to be leaking/seeping more since I went to the synthetic.
But everything runs right and that in itself is all I really need.
It is a rider - not a show bike - and I've always loved the saying ... Just marking my territory...LOL

RK...sounds like you should plan a month vacation up over here. Get your biked tweaked and dialed in by harley and in the mean time sight see on my '83 FL until yours is done.

Weird that all of a sudden all these leaks? That pulley seal on the case eventually goes and need replacing,undertandable. Yours sounds old enough for that to be a consideration. Thats where I am with my '83 FL, that and a few other "things". But the other leaks are just weird.

Oil leaks are annoying no matter how you paint 'em.

the leaking and wheeping at the base gaskets are normal on the evos, it is one problem they had. Twim cams got rid of the gaskets and went with an o'ring, plus a different way of sucuring the head and barrel. One reason to keep up on a leak because after awhile you get new ones and don't know it and can't find them anyway through the oil mess. The tranny leak could be the seal in the primary, they usually go before the mainshaft seal, but both are an easy fix.

I keep it clean to the point that I can keep an eye on the engine. Before I went to the syn it wasn't as bad, the oil never hit the ground in between washes. With the syn it went through a half qt in 2500 miles, no burning but drops on the ground. It started coming out of the top end just enough to look damp on the wrinkle paint.
The underside of the bike is a little bit greasy mess the tranny oil must be spraying on the belt and then on the pulley but just enough to make a mess not soaked or dripping. The tranny leaks about an 1 oz per 1000 miles. I'll get 2-3 drops per parking. I was going to fix it and throw a new belt on with the tires this year but after a close inspection of the belt - It is still rock solid - i decided to just do the tires.




H,
I'm real good at getting that back wheel off so when I get it to your house on the lift - WE can - you show I'll do - the fix - BI can ride up and meet us while we're elbow deep - maybe even get him in there for his 2 cents... From the sound of it and my previous experiences - we'll be done in few hours. I never really had anyone to help me with repairs... other than the guy that wrote the shop manual...

It is 19 years old - low mileage 40k - I had a bad back for about 9 years of that and couldn't get on it - it sat patiently waiting for me... That didn't do it any good. BUT It still runs good and pulls hard, I think it could do a round trip to the east coast with just gas and oil.

No problem, harley dealer for parts is 12 miles away with a choice of 2. The work is comfortable in my garage, and in the summer the inground pool won't have ice on it, makes for softer water. Just bring your bike and manual
deerslayer

+1

Yeah - I take the book where ever I go if I'm not planning on sleeping at home... one never knows what will happen on the road, I like having my very informed friend with me - the guy that wrote the book

I might need a new back tire by then, since we'll have it off - I'll get it shipped to your place and have the guy you use mount and balance it for me... Nothing like new rubber, and a real inspection to keep ya safe on a long trip. I'll do an oil change too - I think Mobil 1 V-Twin syn is everywhere.

As for the pool... I'll bring the cold drinks... you can supply the ice - BI come thirsty!!

I'll see the guys on the way - first stop Phoenix, then New Mexico, A big fat steak in Amarillo, OK, Missouri, Illinois, Ohio, Penn, NY... I did that from memory - did I forget any.... I'd like to visit NC on the way home.

JUST to let you know if you're ever out this way - I might not have a pro lift - bike jack and stands, no pool - garden hose, but i do make some mean grilled meats, Have a shady place to service a bike and plenty of tools just in case. We have several HD stores within reasonable driving distances. You might be out here before I get back there.