Hi guys. I am new to the forum and to harleys. Last summer I bought a 1994 fatboy with the eco. Bike only has 25000 miles. We love it. Now I am at the point where I want to change the fluids. In every else I use synthetic.
I was hoping you guys could steer me in the right direction with my new bike.
what fluids should I use?

 

Go to the oil section of the forum.

 

Seeing that you are new to Evo's, I would get the factory service manual and use what they suggest...

 

Ever body so grumpy 'round here today!

Hotrod's right: HD wrote a book that has all the answers in it. You should trust them.

Here's my answer: (And I'm not saying this is the best answer, or even the right answer, but it is my answer.) Lucas conventional 20W50 in the oil tank, RedLine Shockproof in the trans. Whatever cheapo ATF you can find in the primary.

 

You might find that running synthetics will cause a base gasket leak in your '94.
That is unless someone has changed the head and base gaskets to Cometic or James steel gaskets.

Ask 100 people what fluids you should run in your bike and you'll get 100 different answers.

As for me I run Valvoline VR1 20w-50 in the motor, Amsoil 75-140 in the transmission, and whatever cheap ATF (usually type F) in the primary.

As mentioned previously one of the first things you need for that bike is a Harley Factory Service Manual.
It will give you all kinds of useful information.

 

Conventional Valvolene racing 20w-50, usually a 80w-90 or a 75w-140, or a mix of both in the trans (conventional), and conventional 10w-40 or 15w-40 in the primary. In addition to cylinder base gasket leaks with synthetic, the evo engine seems to make a little more noise with it in there. YD

 

Pretty much how I run mine. I will sometimes run Mystic 15w50 semi-synthetic in the crankcase as the local store as they run sales on it.

 

Vr1 20w50, castrol 75w140 and atf works for me, not only on my Evo. I use this combo on my tc 88 and 103

 

Thanks very much for all the input. I guess my next question is how to get a Harley service manual for that bike. It didn’t come with an owners manual.

 

Your dealer can hook you up. They will want more money than you think you should pay, but you'll be glad you did.

An owner's manual (as opposed to a service manual) can be had off of eBay for cheap.