Visit The Dirt Forum for More Information

Author Topic:   2bbl fuel pull over?
mod5v
Dirt Roller

Total posts: 13
posted May 11, 2004 07:38 PM  
I'm building a mini stock for my 13 year old and when I rev the engine up I have fuel coming out the vent tube and the squrters.This is a 2.5L dodge and the engine viberates quite a bit but I can't aford to have it balanced so I have to live with the viberation.Was wondering if there is a way to reduce the tendancy for the fuel to flood out.The carb is a 4412 holley.

XC man
Dirt Full Roller

Total posts: 39
posted May 11, 2004 08:38 PM  
Have you checked the float level ?

mod5v
Dirt Roller

Total posts: 13
posted May 12, 2004 03:52 AM  
using an electric fuel pump so pressure actually goes down as demand goes up.Theory has it as rpms build the needle and seat should have less pressure on it. But yes I did try and lower the float but did not help.

XC man
Dirt Full Roller

Total posts: 39
posted May 12, 2004 06:15 AM  
Replace float and needle and seat ?

speedyd1
Dirt Maniac

Total posts: 170
posted May 12, 2004 01:55 PM  
where do i start - the pull over condition is relative to the amount of air flow thru the venturis. all two barrel holley's suffer from this at high rpm. they were designed to run on v-8 cars and not on 4 cylinders turning 7000-8000. several attempts have been made to alleviate these problems by several manufacturers. typically they cost as much as twice as much as a stock unit. holley has introduced a keith dorton version of their carbs with this in mind. both come with various things including a new metering block in an attempt to stop it. my sugestion to you would be to spend the money for a modified carb(which might not pass tech) or swap over to a weber carb. the weber carbs were stock for several years and are completely adjustable from top to bottom. i would go with a 32/36 dgv5a for stock or one of the 38mm dgas units for modified. they flow +/- 330 cfm and 490 cfm. they are a bit more complicated to put togethor but are by far the superior choice over a stock holley two barrel.hope this helps.there are several good books out there on the webers for info.

mod5v
Dirt Roller

Total posts: 13
posted May 13, 2004 04:43 AM  
Thanks for the help. I changed to smaller jets. put a 30cc acel pump v/s 50cc a longer vent tube and a vent tube baffel out of a 650 dp I had. All this cut the problem in half and I think for right now It should run good enough to get some practice laps in.I have my eyes peeled for a weber off a 2.3 ford so I can build an adaptor and try that out. Thanks agen..

juliaferrell
Dirt Freak

Total posts: 370
posted May 13, 2004 10:21 AM  
Also take the check ball out and replace it with a plunger underneath the booster. The plunger is heavier than the little check ball and doesn't allow quite the pullover.

speedyd1
Dirt Maniac

Total posts: 170
posted May 13, 2004 06:08 PM  
you can also install a power valve block off and go up a few sizes on your main jets. a lot of times the pull over can actually substitute for the power valve because it comes in at a higher rpm. sounds a little weird but i've had to use it that way when running stock motors and track required carbs. they outlawed all mods so it limited our choices.

Back to the Archives