race fuel or not

[trx250rider]

i did a compression test the other night and it read between 160 and 165 everytime....does this require racing fuel or is pump gas ok...the gas station by my house sells 110 motorcycle gas..is that the same as racing fuel..will it work

[headache]

you should be fine on 93 pump gas. You can always do a plug check to be sure...

[stoopidbot]

If you can get 110 gas use that. Race fuel usually starts at about 104 octane.

[chris46250r]

Originally posted by stoopidbot
If you can get 110 gas use that. Race fuel usually starts at about 104 octane.

Why use it if you dont need it.

[stoopidbot]

burns cleaner. Less deposits on valves.

[gojk]

Originally posted by stoopidbot
burns cleaner. Less deposits on valves.

Ya, I hate when I get deposits on the valves in the R..........

Wait, they don't exist.

I wouldn't waste my money on race fuel. You can actually lose power from using to high of octane.

[quad9]

Originally posted by gojk
Ya, I hate when I get deposits on the valves in the R..........

Wait, they don't exist.

I wouldn't waste my money on race fuel. You can actually lose power from using to high of octane.

yup!! it will run better on 91octane fuel, you dont have the compression that is needed for that fuel.

[troybilt]

Does anybody know what compression ratio requires "X" octane?

[quad9]

around 185-190 start looking at better fuel.
but there are many other factors that also need to be looked at too.

[07HRC450R]

Originally posted by stoopidbot
burns cleaner. Less deposits on valves.
and smells really good out of the exhaust:devil:

[quad9]

Originally posted by 07HRC450R
and smells really good out of the exhaust:devil:

get a good sniff of MRXO1 sometime, and that will be the last time you sniff exhaust, that stuff is nasty smelling!!!lol

[chris46250r]

Originally posted by stoopidbot
burns cleaner. Less deposits on valves.

Do you realize what section you are in?

[stoopidbot]

Originally posted by chris46250r
Do you realize what section you are in?

No I didn't! My bad was thinking 4 stroke!

[my88r]

Originally posted by trx250rider
i did a compression test the other night and it read between 160 and 165 everytime....does this require racing fuel or is pump gas ok...the gas station by my house sells 110 motorcycle gas..is that the same as racing fuel..will it work

not at that compression... keep a eye on the compression. because it is starting to get low.

just make sure it has fresh 93. dont run old gas:D

[trx250rider]

well what is stock compression on it

[quad9]

i have had fresh stock engines that are 165lbs.

[trx250rider]

oh and not to mention, the guy i bought it from did not want to run it on race fuel so im guessing it has a 22 or 23 dome in it...i dont think the compression is low for any other reason like piston and rings...

[trx250rider]

when you do the compression test, do you give it full throtle....i did but the engine was cold..i read that a warm engine reads 5 to 10 pounds more...is this right...and thanks for your help

[my88r]

warm engine- wide open throttle.

160 is starting on the low side. but 165 is fine.

[86 Quad R]

what head gasket is on that engine? if its the stock thick one then that compression reading isnt that bad.

[trx250rider]

i believe it is the stock one

[machwon]

Here's a link to a fuel chart. It gives compression ratio and octane. This is a good starting point but like others said there are other factors.

http://www.msnusers.com/RBRacingTwoStrokePorting/Documents/Fuel%20Chart.jpg

[my88r]

if you do the compression test cold... how much lower will your compression be...