different way to change fuel/air mix?

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Prasinos

Prasinos

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Dec 1, 2008
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I know ethanol has a far higher octane rating as gasoline, i want to say its around 115.

I thought there was someone at the death race that used e85.

I lost the jet because like an idiot i put the old one on top of my engine and drove away.

The reason i thought that e85 would be richer is because i believe Norm said to run on alchohol you have to drill your jet way smaller.

by norman
No! to run methanol you go way bigger in the hole size and across the board needle size and setting.
 
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camlifter

camlifter

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May 4, 2009
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tyrslider said:
I think you mean lower octane don't you? E-85 is Oxygenated 85 Octane? If it has the affect of leaning it out it is comparable to lower octane gas. Higher octane gas burns slower, more controlled and requires more compression to burn properly! So it does run better leaned out but it's not "race" gas it's a properly "tuned" fuel delivery sytem.

2 strokes are typically low compression motors and don't require high octane gas. They do love to run lean though! That is, until they sieze!

Toker, the needle only affects fuel mixture from about 1/4-1/2 throttle. Idle jet (circuit) below 1/4 and main jet above 1/2 throttle.

Don't mean to be nit picky but gasoline properties are widely misunderstood and the source of much confusion.

P.S. If you want to tune your engine, learn how to tune your engine! I think it kind of backward to look for a chemical mixture to solve your engines running issues.
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e85 is 85% ethanol, the 85 refers to the ethanol content not the octane, e85 is 105 octane, thats why the turbo guys run it, you just need to tune for the leaner properties, to run on e85 you generally will need to go up 5 jet sizes, for methanol 10 sizes, thats a rule of thumb and you need to dial it in with spark plug color. i run an e85 mix in my srt4 works great for keeping it in high octane mode.
 
george_n_texas

george_n_texas

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Prasinos said:
I lost the jet because like an idiot i put the old one on top of my engine and drove away.
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I did exactly the same thing doin a brake job on a coworker's car only it was a Buliva railroad aprooved watch I had just paid off and had to have to be a transit bus driver...needless to say I lost money on that brake job.
 
camlifter

camlifter

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you can add xylean to gas to raise the octane, to richen a fuel mix the fuel your using would need to have a lighter specific gravity than gasoline. that would cause more fuel to flow through the same size jet making it richer, i don't know what that fuel would be, if you want to really play with your fuel go to this site, they have everything you need.
https://pricechemical.com/
 
X

xlite

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Jun 18, 2009
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Prasinos said:
I lost the jet because like an idiot i put the old one on top of my engine and drove away.
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LOL! I never did that! I specially didn't do it with my Garmin Rhino GPS on the back rack. And I didn't do it again with my best 10mm wrench a week later. :)

You can make your jet leaner by putting tiny pieces of wire from stranded cable in the hole. At least til the new jet comes in. Would be much better to order a set of tiny drills than another jet. 3 minutes with a pin vise and bic lighter.
 
Prasinos

Prasinos

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idk i bought some tiny drill bits and my drill press broke all of them, they were cheap but the press just idint true enough, is there something im doing wrong?
 
Venice Motor Bikes

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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My brother once blew up the engine in his truck by messing with the float level... (too lean!)

There is supposed to be a adequate amount of fuel in the float bowl to feed enough fuel up through the jet tube in all conditions.
The jet is what measures the fuel into the airstream, starving the the jet of gas is not the right way to lean out the mixture!

When you figure in the fact that the carb will be tilted at different levels as you go up & down hills & race around corners, (dropping the fuel level even more), you don't want it ever getting too lean & hurting the engine.

Why is it so hard to just jet it right in the first place & be done with it??
 
X

xlite

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Jun 18, 2009
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Venice Motor Bikes said:
My brother once blew up the engine in his truck by messing with the float level... (too lean!)

Why is it so hard to just jet it right in the first place & be done with it??
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You are just as like to screw up the mixture with a jet as playing with the float. More so if Joe is right. And I don't think it's as easy to blow up one of these engine as many think. I put 300 miles on a trip this summer with a half size jet and white/grey plug. Great gas mileage and no overheating or seizing. Out af several dozen motors I've never had one seize. Even with 50:1 marine oil. These are not truck motors.

I commend you on your abilty to "jet it right in the first place & be done with it". Most are not so lucky. And if you think ordering jets or playing with solder and a pin vice are easier then feel free.

I wonder why so many resist this easy way to adjust mixture. Even Barely seems to have come around. :)
 
Bikeguy Joe

Bikeguy Joe

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I will add that the float adjustment is as touchy as many other things and a heavy hand will do more harm than good. With the "float method" you are adjusting the overall level tipped, not tipped, ect. This changes the atmospheric pressure in the float chamber and changes the amount of fuel dispresed through the given size jet.

I believe Mr. xlite has the best explanation as to why and how adjusting the overall float bowl level works....Mr. xlite
 
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