this is my first harley bike ever so if i sound stupid i am, but my question is what kind of gas should i use in my 98rk premium or regular. thanks for any help

 

Run the highest octane you can find.

 

Stock evo is 8.5 to 1 compression. 87 octane will work fine. Higher octane fuel only works for higher compression engines.

 

It will run fine on either. If you are driving hard in real hot weather, hight octane fuel will help.

 

Dude...........Bust out the extra .15 - .20 cents a gallon and run the good stuff in your harley.As you trusty friend, it deserves it.

Ride Fast....Ride Safe

 

My 86 runs fine on either, but gets better mileage on the good stuff. I use it just to extend my range.

 

even with gas prices soaring every day. just spend the extra dollar at each fill up and run the good stuff. it cost me 16 bucks to fill my bike on high test. that extra dollar ain't gonna kill ya.

 

Run 87 octane....the EVO was designed to run on this stuff. The exception was the 1995-1998 EFI EVO though as these were designed to run on 91+ octane.

If the modifications were made to the engine like raising compression....then one probably should run higher grade of gasoline. A little pinging from taking off from a stop isn't going to hurt anything either.

If the bike does not ping under normal conditions and the bike is properly tuned...just run 87.

 

Suggestion! run a tank of 87 Octane if it does not ping your Golden,if it does step it up a notch.No need to run anything higher than the motor needs.Good Luck.

 

I think MOCO reccomends highest octane possible for 1998 RK. Thats what it says in the manual. I have a 1998 Ultra. Same motor. Same reccomendation