Motorcycle Repair: 1993 Fatboy, synthetic motor oil, northern peoria

Question
Hey Johnny,

Welcome to your new digs in Northern Phoenix.  I saw your ad in a biker magazine.  

Can I switch from mineral to synthetic motor oil after 23K on a 1993 Fatboy?  I live in northern Peoria.  

I bought the bike used and it has long shot pipes with the original carb.  Do you rec jetting or replacing the carb?

What modifications do I need to make to a 2001 factory Fatboy seat fit my 1993 Fatboy?  I got the seat free from a buddy.

Thanks, Bill

Answer
Hi Bill
Please don't ever use synthetic motor oil in your Harley. It will distroy the motor. It is o.k. to use in your car because your car has Plain bearings and Not roller bearings. The oil is too slick and the bearing rollers slide in the oil instead of turning in the oil and it causes flat spots in the bearings in the lower end rods and will take out the motor. I have seen it done more the 10 times. I will only use Mineral Harley oils or Castro or any oils like them.   as far as jetting the carb. It is not the carb that is the problem... It is the exhaust system. I can dyno the bike for a month and never get the jetting correctly with the exhaust system you are running now. Install a good exhaust system and the carb jetting is easy and you will gain horse power and torque accross the entire power band.about 10 to 12 horse power and 12 to 15 ft lbs of torqte.. I like the White Brothers E-Series 2 into 1 exhaust system it is by far the best on the market. I dont know about the seat..  southside johnny  623-587-4533