race gas in a stock bike?

[dkortje]

What are all of your thoughts on using race gas in a stock bike? I've got a 03 YZ125 and have always just used premium pump gas, which in Kansas is 91 octane (we are approx 1000 ft elevation). Does race gas really help, if so what do you all use?

Thanks

 

[mx547]

i ran phillips b35 with half pump 93 in my last two bikes (stock). i highly recommend it.

 

[Senior KX Rider]

I run race fuel in my 125(stock motor) because of the consistency. Makes jetting much easier and the throttle respnse is worth the money IMO :)

 

[motometal]

some guys I ride with that use pump fuel just seized two bikes on the same day due to bad fuel.  not sure specifically what was wrong with the fuel, but I would have to think race fuel from a good source (preferably NOT an underground tank) would have been much safer.

 

[WhKnuckle]

I began using race gas in my KTM 250SX's a couple of years ago because they needed it (you can't get decent premium here in Houston). They'd ping with pump gas and jetting was less consistent with 50/50 pump/race gas. I kept using it in my CR500AF just because it burns cleaner and is so much more reliable. IMO, pump gas is OK unless it's mixed for a high-smog area - then it can have some not-so-desirable clean-burn additives. I buy race gas in 5 gallon cans (VP C12) and it costs me about $6 per gallon, but I don't have to wonder what I'm putting in my $10K hot rod. Cheap peace of mind.

 

[jmics19067]

I use the sealed 5 gallon cans of c12 also in a stock 94 yz 250 for play riding.I am impressed with consistency enough that I won't go back to pump. I dont even burn pump in my lawnmower anymore.

 

[sharp7277]

Do you have to rejet after mixing 50/50 race gas?

 

[Moto Squid]

after making the switch on my relatively stock cr I'd never go back to pump. Everything burns very cleanly, you actually have a chance of getting jetted and the throttle becomes crisp. Oh ya, don't forget race gas smells better too :)

 

[Dirtvet]

Do lower compression big bore engines benefit as much as higher compression smaller bikes? WhKnuckle, could you tell a difference in your CR500AF too? I too live in the Houston area, and have an old 450 2-stroke that I want to protect. It has a low 8.8:1 compression.

 

[MXSparx]

When switching to a 50/50 mix pump and race, which direction will the jetting change? I'm thinking of giving it a shot myself, but want to make sure I have the appropriate jets.

 

[nephron]

I take it search isn't working. ;)

This topic may be more prolific than oil, 'what kind do you use?'.

No offense. dkortje--there are so many threads on this your optic nerves will melt and your occipital cortices will mold together taking it all in. Suffice it to say there's a huge difference in performance, even in a stocker, but the benefit to cost ratio is definitely a personal issue.

 

[dkortje]

Originally posted by nephron
I take it search isn't working. ;)

This topic may be more prolific than oil, 'what kind do you use?'.

No offense. dkortje--there are so many threads on this your optic nerves will melt and your occipital cortices will mold together taking it all in. Suffice it to say there's a huge difference in performance, even in a stocker, but the benefit to cost ratio is definitely a personal issue.

Sorry, I know this is a popular question,(probably why so many replies), please forgive my laziness :whiner: .

But thanks ofr all the great ideas. I think I will probably try race gas 50/50, although our local supercross track took out my fibula a few weeks ago, so it may be a few more weeks :uh: !

 

[WhKnuckle]

TommyGun - Sorry for not replying, haven't looked at this thread for a while. As far as helping lower compression motors, it probably doesn't - but I use it because it's consistent and I can jet the bike and pretty much just leave it alone unless the weather changes a lot. Pump gas in Houston is very inconsistent. On my KTM's (that do have high compression), they'd ping badly with pump gas on one tank, then run OK on the next. Fooey on that. Keep in mind that a 8.8:1 compression ratio is a lot higher than it sounds - 2 strokes can't get the same ratios as 4 strokes 'cuz of all those holes in the cylinder. It's a little more trouble and a little more money, but it's worth it to me.

 

[motometal]

to answer your question regarding jetting, MXSPARX, it really depends on how efficiently you were burning your pump gas vs. the new race fuel.  For example, if some of the pump fuel was just being wasted out of the tail pipe (fuel with a high end point vs. combustion temp) and your new fuel mix is being 99% utilized, your bike will run richer.