I just bought a bike 2003 Fatboy Anniversary, with only 3535 miles. Until I can get it in for a change I need to add oil. Since it has low miles I don't believe it's ever been changed. What do I put in it? I'm a newbee to Harley and don't want to mix oils. It will be all Syn soon but need to add some to get it there.

 

No offense but if you don't know what kind of oil is in it, no matter what you do, you stand a good chance of mixing the oils. Why not just do a complete oil change and put your mind to rest.

 

Thanks that was also my thought but was getting it into the shop for a complete check and was concidering just having them do it all motor,trans and primary with synthetic. I will probably do the motor and let them do the rest.

 

I just did the full service on my 2003 Anniversary Fatty.......do it yourself. Trust me, if I can do it...you can do it. You'll save a ton of money and it won't take you more than 1.5 hours at the most. There's a ton of awesome videos on youtube.

I used Mobil 1 15w50 in the engine, Mobil 1 75 90 in the tranny and Mobil 1 10w 40 motorcycle racing oil in the primary.

 

Another tip......for the primary I went through the chain inspection cover instead of dealing with the derby cover. The gasket there can be reused there multiple times and the bolts always seem to be easier to remove. Only issue is you can't really check the level. I just add a quart....maybe a smidge more.....and it's fine. Also be careful not to over tighten that drain plug. It's smaller than the other 2 and the primary can strip out pretty easily. Use a torque wrench to ensure you don't over tighten.

 

 

First I'd like to thank you all for the help. I have ordered an owners manual so that i'll have it going forward, it should be here on May 4th. Joining this forum has been very helpful. I've had a Honda forever and that uses the same oil sump as the motor for the tranny so this takes a little more attention and after investing real money for this bike I'm probably a little over cautious.