What gas to use in motorcycle?

Question

I have a 1982 yamaha xt200 four stroke. The sticker on it says "GASOLINE GRADE: REGULAR (LEADED)." I add a lead additive in the fuel. The second thing on the sticker says "RESEARCH OCTANE: 91 MIN." I've been using regular gas. Should I use premium gas and what would the difference be? Thanks.

Answer 1

Higher octane gas burns more efficiently.
Lower octane doesn't completely burn and leaves behind a lot of carbon build-up.
The carbon can ignite when hot, even without a spark from the spark plug.
That's where the term "pre-ignition" comes from.
Pre-ignition sounds like the engine is knocking.
If you don't notice that problem, I wouldn't worry to much about the octane rating.

Answer 2

as long as you keep using the lead additive (read the below site esp under the last section of the measurement) you are raising the octane rating of the gas leaded has a higher rating than unleaded so 87 octane is more like 90 octane after you put the lead additive in it ( check the bottle some have it on it on much it raises it) the rating only is for antiknock properties so if the bike rattles a little on hard take offs use 89 w/the additive hopr this helps GL note everyone octane doesnt have a thing to do with how the fuel burns that is a myth

Answer 3

Any motorcycle made in the days of leaded gas should be run with a lead additive. Modern nolead bikes have much harder valves and valve seats, than the leaded fuel engines. The lead in the gas served as a damper between valves and seats, and if you do not use an additive, the life of valves and seats is reduced. Regular is OK, if the engine does not ping or knock under load. If you have any sign of detonation, or pinging, use 91 octane, and always use lead additive.


Tomcotexas.

Answer 4

Tell ya what. the difference between cheap gas and premium is really evident on a motorcycle. My kids 71 CB750 was made for leaded gas.
We just run it on plain pump fuel. But if we run it on low octane cheap stuff its marginal on power, and gets about 30-35 mpg. But if he uses highest octane available, and adds octane booster, power is much greater, and gets 50+ mpg.
All freeway, 70 miles a day, the difference in power and mileage more then pays for the premium. If its fuel injected, your not gonna notice, unless your injection calibrates for the octane. However older carbeurated engines, like 99 percent of all bikes, show dramatic improvements, and the higher the compression ratio, the more dramatic. I cannot believe an 82 bike was ever made for leaded gas.

Answer 5

Higher compression engines need a higher octane of gas to fully combust...

if your bike says to use a 91 minimum, go ahead and use the minimum to reduce the risk of any crud buildup inside the engine (especially since it is an older bike).

On a tangent... if your bike suggests using a lower octane, there is really no reason to buy a higher octane gas... it is nothing more than a waste of money.

Answer 6

Try regular without the additive. If it burns okay, without knocking, then you're all good. If it knocks, try premium gas.

My 1978 Honda XL350 was made in the days of leaded gas, but worked just fine with premium unleaded, up until I stopped riding it in 1988.

Answer 7

its always best to run high octane in your bike. i know guys that run low octane and they bike doesnt run well where i know first hand the bike runs best on high octane

Answer 8

that one should run good on regular i run mine on regular and it was meant to be run on a higher octane ,just use a good brand and you should be fine,good luck .

Answer 9

Yes, use premium fuel, it keeps your engine and carbs cleaner and more efficient. Gasoiline from today and yesterday are WAY different!!!!!!!