yes Mobile1 V-Twin , yes when possible always use a oil Designed for a 4stroke motorcycles,
Make sure the oil you use is (and says it on the bottle)design for motorcycles, and design for a 4 cycle motorcycle engine, not a 2 cycle(2cycle/2stroke I.E like some off road dirt bikes or chainsaws weed eater type engines that use oil mixed in the gasoline) not oil for regular 4 cycle 4 stroke gas engines ..ie regular cars and trucks ..
in primary and make sure it is for WET CLUTCH USE for in the primary(trans) or you could ruin your clutch very QUICK.
definitely reccomend full synthetic oil , like Royal Purple MaxCycle or mobile 1 V-Twin, red line, ams oil.
USE the best that you can afford , same goes for the filter (oil & air)...
Make sure the oils you choose is designed for MOTORCYCLES
Unless it is an emergency and then look at what your manual says to use for most it says that you can use,
.if an emergency you can use diesel oil.If it is necessary to add oil and Harley-Davidson oil(or your MC prefered oil) is not
available, use an oil certified for diesel engines. Acceptable
diesel engine oil designations include CF-4, CG-4, CH-4 and
CI4. The preferred viscosities for the diesel engine oils, in
descending order, are 20W-50, 15W-40 and 10W-40.
otherwise use motorcycle oils.
BUT Remember this...
yes OIL is cheap and easy compared to an engine rebuild .or trans rebuild.. your oil and filter is the cheapest insurance for your engine , no matter what you drive or ride , use the best(that you can afford) and change it regularly . its worth it. gotta take care of the buell. and other vehicles for that matter. I would rather pay the extra $5-$10 more per bottle for the best oil for ALL my vehicles including the buell, why take a chance on it just cause you're savin a little $$ but thats my opinion. (the cost isn't going to add to big amount even if you're change 3-4 times per year.)
USE the best that you can afford , same goes for the filter (oil & air)...
it's always better safe than sorry
.
I fyou dont already have one it would be a great ideal and a big help to yourself in doing alot of your own maintenance to buy or find a downloadable Service Manual for your 99 X1. do a google search for a PDF version of the service manual.
or buy it here from
Buellparts.net ,
or here at E-BAY.... or try AmericanSportBike.com
here are a few good threads for although your 99 X1 will be a bit different, some info still pretains to your bike as far as oil and primary oil, and some other info.
best-motor-oil-to-use
OilPrimary-change
newbie-.-what-oil-would-you-recommend-