Carb Setup

[steveshawjr]

looking for a base carb setup i still have to pull a vacuum reading but a good base would help.

holley 350

looking for a starting jet size , squiter size and power valve


198m above sea level


current setup
55 pv
55 jet
25 squirter


also is there anyway to help with pullover intll i can get the diaframe

[longhornracer]

Im sure you will get alot of different answers on this. But from what I have ran is a 69-72 jet size 35 power valve. And the pullover issue i could never figure out till i bought the diphragm from JBV Heads

[return to dirt]

stock jet is a 61, try about a 63 to start with and check the plugs. joes diaphram works good. i have one i have used since 07 or 08. still in good shape but the orange flapper valve will need replaced every couple years or so. i have also cut down an umbrella type valve seal and used it with good success.

olin

[youngengines]

Any one have a contact number for JBV heads?
I sent an e-mail with no responce.

[84Dave]

Use a Holley #19 or #21 squirter. A #25 is too much for the size of the carb on a 4-cylinder. Do not use the 'tube' squirter. Use the standard 'stub' squirter. At the stub exit holes, use the tapered end of a 1/16" drill bit and gently drill a taper @ the squirter exit holes. This has the effect of 'fanning' the fuel as it exits the squirter, for much better atomization. If the 350 has been around awhile, replace the o-ring on the needle-seat assembly. With the engine & under-hood temp warm, clip the engine and make sure the bowl fuel-level is about 1/16" BELOW the bottom threads of the sight-plug hole. -Dave-

[Doug_Guilds]

Use a Holley #19 or #21 squirter. A #25 is too much for the size of the carb on a 4-cylinder. Do not use the 'tube' squirter. Use the standard 'stub' squirter. At the stub exit holes, use the tapered end of a 1/16" drill bit and gently drill a taper @ the squirter exit holes. This has the effect of 'fanning' the fuel as it exits the squirter, for much better atomization. If the 350 has been around awhile, replace the o-ring on the needle-seat assembly. With the engine & under-hood temp warm, clip the engine and make sure the bowl fuel-level is about 1/16" BELOW the bottom threads of the sight-plug hole. -Dave-


Quick question. Is that a 19-21 squirter WITH a anti pullover diaphragm? Reason I asked is a article I read mentioned swapping out a squirter 10 numbers above what you would normally run because of the shortened stroke of the pump shot. That is if I remember right. :/

[return to dirt]

using the diaphragms from joe that i have used there was no difference in the accel. pump shot. i still had more then enough fuel on the accel. the diaphragms only stop flow on wide open or near wide open throttle.

olin

[Doug_Guilds]

I had to make mine myself so there is a dead spot from when the pump shot stops to when the main metering circuit takes over, I probably only have 1/3 throttle before the diaphragm closes off the umbrella seal. That's the only way it will stop the pullover.

Since I have hopefully cured my other ailment, which was probably the o-ring around the needle and seat causing a flooding condition, maybe I can work with the diaphragm more now and get that dead spot out.

[youngengines]

using the diaphragms from joe that i have used there was no difference in the accel. pump shot. i still had more then enough fuel on the accel. the diaphragms only stop flow on wide open or near wide open throttle.

olin

You got a phone # for Joe?

[84Dave]

For any given stroke on the accelerator pump, the smaller the squirter, the longer period of time on the pump shot. And a 50cc pump obviously provides/makes available slightly more volume per pump shot than a 30cc pump. Realizing that the 50cc & 30cc numbers are the fuel volume available from TEN full shots of the pump. NOT a single shot of the pump. Bottom line? The diameter of the squirter-hole exit primarily determines the time-length of the single shot from the pump. Whether a 50cc or 30cc pump. Example: a .025" (#25) squirter will have a shorter full-shot 'squirt time' than a .019" (#19) squirter. -Dave-

[youngengines]

No one got a number for JBV- Heads?

[jatchis]

No one got a number for JBV- Heads?


Joe is retired. He will still respond to emails, but it may take some time, so be patient.