440ex signature edelbrock carb

[TTlt250r]

ok heres the deal i just built the top end on my buddies bike and ive got the bike running good but have had lots of problems trying to tune the carb i was wondering if there is anyone out there who has the same mods and could tell me where the have the carb set. the problem is that the bike is running way too lean on the top end. ive run it wide open pulled the clutch killed it and checked the plug it is flakey from excessive burn off i even called edelbrock and ordered the 29 needle as it comes with the 25 stock. the mods are lrd pipe 2 stage hotcam k&n cdi box. please help

[TTlt250r]

almost forgot we always run 110 octane does high octane gas burn leaner or hotter or should the plug still be light brown?

[krt400ex]

Originally posted by TTlt250r
almost forgot we always run 110 octane does high octane gas burn leaner or hotter or should the plug still be light brown?


higher octane will cause u to need to lean oput ur jetting. i think when ur jetting is correct, u will be running a litlle cooler

[GPracer2500]

Originally posted by krt400ex
higher octane will cause u to need to lean out ur jetting....

Nope.

I feel like I've said it a thousand times but I guess I need to keep saying it. Octane rating is ONLY a measure of a fuels resistance to detonation. Octane rating alone tells you nothing else about how a fuel will perform. If anything, most (but certainly not all) "racing fuels" need richer jetting than pump fuel, not leaner jetting. But that has nothing to do with octane rating--you've got to look at other specifications of the fuel to get an idea about how it needs to be jetted and then test to confirm.

[krt400ex]

Originally posted by GPracer2500
Nope.

I feel like I've said it a thousand times but I guess I need to keep saying it. Octane rating is ONLY a measure of a fuels resistance to detonation. Octane rating alone tells you nothing else about how a fuel will perform. If anything, most (but certainly not all) "racing fuels" need richer jetting than pump fuel, not leaner jetting. But that has nothing to do with octane rating--you've got to look at other specifications of the fuel to get an idea about how it needs to be jetted and then test to confirm.


u r right, i meant oxegenated fuels.

u will need to lean out ur jetting if u run oxegenated fuels beacause...i know what i need to say but i don't know how to say it. GPracer u think u could help me out?

[GPracer2500]

Originally posted by krt400ex
u r right, i meant oxegenated fuels.

u will need to lean out ur jetting if u run oxegenated fuels beacause...i know what i need to say but i don't know how to say it. GPracer u think u could help me out?

Fuel's with oxygenates need richer jetting not leaner jetting.

[F-16Guy]

Specific gravity:devil:

[krt400ex]

Originally posted by GPracer2500
Fuel's with oxygenates need richer jetting not leaner jetting.


wow i am really messed up......haha oh well.

thanks for clarifying

[TTlt250r]

glad you guys sorted that out but how about some help with the carb?

[xxnightraven73x]

ship it to me and ill send you my stocker jetted for my 440 haha:devil:

[krt400ex]

Originally posted by GPracer2500
Fuel's with oxygenates need richer jetting not leaner jetting.



ya, i got it now, because u need to compensate for the xtra oxegen that is already in the gas....right?

[krt400ex]

Originally posted by TTlt250r
glad you guys sorted that out but how about some help with the carb? i don't know anything about the edlebrock carbs....sry