gas?

[EX400rider]

With a stock 400 EX what would be best to run. I am running 93 right now.

[TwentyBelow131]

87-93 octane will be fine

93

[400exrider26]

in the owners manuel it says to run 92 or above grade fuel

[rooster_20]

oops im tight i run 87 lol

[PowerJunkie]

you wont be laughing when your engine dies. lol

[rooster300ex]

it says 92 octane in the manual, so 91 or 93 would be fine. everybody i know runs 87 in a stock motor.

[HondaEXrider22]

I run 93 in my 250 and 400 and both run great.

[srfootball50]

you dont need to run 93 octane unless you have an aftermarket high compression piston if you dont it is fine to run the cheapest pump gas

[400exrider707]

Originally posted by srfootball50
you dont need to run 93 octane unless you have an aftermarket high compression piston if you dont it is fine to run the cheapest pump gas

Yeah what he said. Just remember higher octane wont equal higher horsepower. In fact it just makes your quad harder to start. Only once you start bumping up comrpression or advancing timing should you even look at other fuel options.

[rooster300ex]

mine is 11:1 and i still use real good high octane gas.

if you don't use 92 you are an idiot...what are you saving in a 3 gallon tank by using 93 instead of 87 like 60 cents? wow

I used 87 in my stock motor because that is what my dad bought for the lawn mower. now I have a high comp piston and have to go buy my own gas.

[Mad*Ex*Rider]

i have a hot cams camshaft, jet kit, and a pipe on my 99', i was using 87 for a while until i found out that i should be using higher octane. i havent actually put the higher octane gas in yet but i did put some octane booster into tha tank full of 87. most people say you won't notice a difference but i noticed a substantial difference in the low end power and throttle sensitivity. does anybody kknow a difference from 87-92 octane?

Originally posted by Mad*Ex*Rider
does anybody kknow a difference from 87-92 octane? my engine sound betetr....some say theirs will make a knocking or pinging noise with 87 in it

[srfootball50]

Originally posted by MixMasterMike
if you don't use 92 you are an idiot...what are you saving in a 3 gallon tank by using 93 instead of 87 like 60 cents? wow

ya its not much more for the 92 octane but if you dont need to run it why waste your money you only need a high octane gas if you have a high compression piston your engine will run the same on 92 as it would on 87 if you have stock compression so in my opinion you are stupid if you run gas that costs more when you dont need to

[Iliketogofast]

You don't need high octane gas unless you have spark knock when you run lower. It will make a pink noise like a spring or something, IDK how to describe it. But unless it makes a different noise when you have differen grades, you don't need it.

[400exrider26]

also, alot of 300exs dont need 92, they can run on 87.. but 400exs are made to run on 92 or above... it will tell you that right in the 400ex manuel

[hondardr4life]

400's do have a slightly higher compression than a 300ex. But it won't hurt it. All my friends with 400's run 87 just because thats what their dad buy for the tractor. Trust me, 87 won't hurt your quad.

[jak1389]

i ran 87 on my xr, 300ex, z400, and my 400ex. all of htme ran really well. now that i havea higher comp in my 400ex i will be running a 93 octane.

[blastereatin250]

I always run 93 in my 250 becuase I think it pulls harder. I think you should listen to the manual and put in the octane it says or higher. If it was safe to go lower, then the manual would say it was.

[Chino]

13:1 Je piston
Tc 926 gncc regrind cam
Port n Polish
426 Ex

114 octane Turbo Blue

[hondardr4life]

Originally posted by blastereatin250
I always run 93 in my 250 becuase I think it pulls harder. I think you should listen to the manual and put in the octane it says or higher. If it was safe to go lower, then the manual would say it was.

That is all in your head. It makes you think you are going faster because you want it to go faster.

higher octane in a stock motor... how I understand it will alter the jetting a little.

why is it that a yz250f with a stock 13.5:1 piston is ok to run on 93 octain but in a 400 it isnt

maby other things alter it.

[plkmonster2]

The YZf is liquid cooled....

[bwamos]

Cant get anything out here above 87 octane unless you buy Race Fuel.

My 11:1 330 has no issues with it unless I'm in the dunes.. then I buy the 96 from the shop out there.

Of course I run 2 FST oil coolers on my 330ex to help it run that much cooler so it doesn't detonate as easy.

[400exrules]

i run 89 no probs