on the su carbs its calls for 20w oil for the slide towers. i cant find any straight 20w oil. ive been told that atf dextron2 is a close substitute. please help with any suggestions. thanks. steve

I use ATF, others have their own ideas.

Do a search on SU Oil, you can be sure that you will get a variety of suggestions!

[must admit I haven't heard of olive oil yet, but it must be pretty close to the correct weight]!

I've been told that Harley or other motorcycle shops have 20w oil. Motorsport Auto in Los Angeles also sells it in small bottles. Kinda expensive per ounce, though.

FYI,

I decided to use motorcycle fork oil. It's designed for a sliding mechanism and has anti-foaming additives as well. Your choices are wide.....5w, 7w, 10w, 15w 20w!!! If there are any drawbacks with this oil, I have encountered none! I am using 15w, in order to obtain a little quicker piston/needle responce. When choosing oil viscousity, consider the temperature of where you live and drive your toy. Cold weather, use lighter oil and for hot weather, use heavier oil. However, I wouldn't recommend going over the recommended 20w.

But that's just one man's opinion!!!

Here's what I've used. It's cheap and easy to find at most hardware stores:

http://automotive.aubuchonhardware.com/engine_lubricants_and_additives/penetrating_oil_and_lithium_grease/3-in-1_motor_oil-575407.asp

20W is the yard stick by which all other "performance" oils are measured. Expand your search & get what the manufacturer wants you to use. I've used 20W motorcycle shock oil & 20W Yamaha brand motor oil & couldn't tell the difference. The point is that 20W allows the appropriate amount of vacum to occur at low rpm, yet allow the engine to accellerate smoothly to wide open throttle no matter what rpm you start at - just perfect for all around driveability. ATF, WD40, 3n1 oil are all better then nothing, but I also had a buddy that raced with SUs & he ran them empty because he only cared about high rpms & didn't want anything getting in the way of a wide open venturi.

there in lies the problem. part of my asking people in the know at this site is because i found out what the manufacturor requires and it is no longer available from the factory. ive spoken with numerous parts guys at nissan----and theyve all told me -----20w and we dont have it -----and cant get it. i want a comparable 20w that is suitable.----for a multitude of reasons it needs to be 2 things---20w and non foaming. ANYONE please correct if im wrong but ive read many times in motorcycle magazines that atf is 7w , ----the perfect fix for those wanting to dial in their shocks between 5w and 10w. atf is non foaming. ------im just looking for something that will work. if 20w shock oil is cool-----then that do it. thanks . steve

If your Nissan dealer is telling you "20w and we dont have it -----and cant get it." They aren't trying hard enough. Nissan never manufactured 20wt. oil, they bought it and now do not carry it because there are not enough demands for it to make it enconomically viable for them.

It is available elsewhere. I use it exclusively in my SU's. Look around a bit and you'll be able to find it too.

I've used Marvel Mystery Oil. Someone told me about it and I thought it worked great. Even if it should get sucked in, it will only clean your carbs and valves. It's intended use... to put in your tank, so I figured it wouldn't foul plugs, etc.

thats good info to know-----ill keep that in mind and keep on lookin. :classic: steve

ive always used marvel mystery oil and never had any problems with my carbs at all, if anything they helped the car run better

ive talked to a few people with 30+ years on these carbs and apparently sewing machine oil is the way to go, its nearly spot on to the original oil. you can get it from petrol stations (or i assume sewing machine shops?:stupid: ) the only probelm i have with the stuff is it seems to dissapear after a while, so i tend to run no oil at all.