pull your carbs, if there still dirty clean your tank and get a new fuel filter, im pretty sure you want to run premium gas too, the reason is lower octane gas can cause a knock, its because it wants to prematurely combust in higher compression motors. dont cheap out on a fuel filter either, get a new one, if its not doing its job your carbs cant do their job of suppling gas to the motor. if it will start with the choke on, but dies out with it off its def. a dirty carb

 

im pretty sure 87 reg octane will work fine, considering our motorcycles were made to run on that. don't quote me on the manual for recommended gasoline, but i would imagine they would want you to stick to the 87/89 octaine area. if your engine knocks with reg gasoline... ouch.

 

An e string from a guitar works great.

 

Correct... do not run any other octane then what your manual asks for. Older bikes use 87, I believe some of the newer 07+ use 91. If you have knocking then you have some other bigger problems.

 

octane is fuels resistance to knocking, high compression motors can run on regular, but call for higher octane, and most liquid cooled inline 4's are fairly high compression. in theory a bike would run better on regular because it wants to ignite easier, but if it ignites early, prematurely (kinda like a personal problem :P), that is when you get problems, knock, pinging, ect. i am new to bikes but i have been around cars a bit, and its fact that a motor with higher compression needs higher octane to run without knocking. most cars now have knock sensors that can retard timing of the motor to make it run on regular gas if it is a higher compression motor. i am fairly new to bikes so i dont know if they would have this, but i do know i run premium because im pretty sure i have seen that the f3 calls for 91 octane or higher. it will run on regular gas, and probably will run fine, but i just choose to run higher octane because i think i have read that the f3 calls for it. i did run some regular through it because thats all the gas station had when i was working on it, and it didnt idle funny, or do anything odd, so your probably fine on it, but it is fact that higher compression motors need higher octane.

 

another cool thing a knock sensor does it will actually have the timing advanced just before the motor would start to ping to get the most fuel economy/power, carbon build up can also cause a knock, this is because if their is crap in the cylinder there will be less space, thus increasing compression, so if you get a knock you can try and run some cleaner though it and see if that helps, if you motor has a bad knock, its probably something worse, but worth a shot lol, a knock sensor actually adjust the variable valve timing.