I've got the motion pro screw driver for adjusting the carbs it great just needed alittle more of a bend like 110 degrees instead of the 90 it comes with and now it misses my exhaust on one side and on the other side misses my oil line so from either side I can reach and adjust both carbs this tool works great. $30 will spent!

 

I have my new needles and seat in. Guess what....same dang thing.[img]i/expressions/face-icon-small-mad.gif[/img][img]i/expressions/face-icon-small-disgusted.gif[/img][img]i/expressions/face-icon-small-mad.gif[/img] I guess I am just going to have to.......????????? something.

One question, why is it that everybody else isn't having these problems? Its not like we are the only couple people that run race fuel.

SOOOO any ideas on where I need to go now???


dieselgeek are you from New Hampshire??? I hope so.[img]i/expressions/face-icon-small-cool.gif[/img]

 

Go ahead and set it as best you can to the closest the the matting line or just above, remember the lower the level the less travel room the needle has so when it's full opened the needle doesnt travel much and you'll get just a trickle of fuel thats not enough to run compensate the demand, unless you do as I did and give it alittle more range of travel by doing what I posted earlier, hey you have a spare set now so go ahaed and try it on the old pair, if you need details let me know. I would also start going down on the main jets, being that race fuel flows more so it's equal to a larger size even though it's a size smaller jet so basically dont worry about the # on the main jet just make sure to check the plug.

Question what main jets where you running before the 686 upgrade?

 

I asked my racing buddies about the fuel - it relates to specific gravity / density of the fuel. Some race fuels are more dense, some less dense. Can you tell me exactly what fuel you're running, and maybe point me to some online specs?

 

VP C12
• Color: Green
• Lead: 4.23 Grams per gallon
• Motor Octane: 108
• Specific gravity: .717 at 60° F

Anybody know what the specific gravity of 93pump gas is?

Its a little different than that for me. I had a big timimng change on my cam, -6 degree, and ran pump gas when I first went to the 686. I think before I was at a 165/170.

I am going to try and bend them like you said earlier. We will see how it turns out.

 

I see you no higher than 180/185 mains with the c12

 

Foudn a website with fuel ratings... here's pump gas:
Clicky Clickerton

So if 93 octane pump gas has a specific gravity of .743, and your fuel has a SG of .717, this means that you would need to jet richer than stock?

 

My problem isn't with the jets, its with the float level. But I am at 185/190 now and rich, but my floats are high soooooooo????


Thanks for the info dieselgeek!!![img]i/expressions/face-icon-small-cool.gif[/img] But it means I would need to jet more lean than with pump gas. The race fuel is lighter,.......hmmmm or would I...??? Now i am confused. The race fuel would be less dense so ......dang it.......I am going to have to research this.

 

I think the less SG the less dense, usually meaning thinner, so more should flow through a given opening with a lower SG.
Sort of like water passing through a given opening vs. oil through that same opening............I Think.

 

Thats what I am thinking too. Soo I would need to jet more lean on this race fuel than I would on pump gas. Yup thats right.

But whats really messed up is methanol has a S.G. of .796, my floats are going to be alllll messed up. If I could ever get past the fuel level I don't have a problem jetting.


I think I am going to just skip this gas stuff. I am tired of messing with it.