302 carb help

BAD BOB · 03-03-2009, 06:38 PM

I got a 302 with heads cam headers and msd ign and i put a holley 750 on it and it seems to be loading up. Any help on if i should change jets or something?

WWhittle · 03-03-2009, 06:46 PM

what jets are in it and what is it doing?

LXtasy · 03-03-2009, 06:48 PM

Which heads and cam? Dp or vacuum secondaries? Transmission? rear gear?

750 could be to much carb IMO.

05Saleen · 03-03-2009, 07:54 PM

Quote:

Originally Posted by BAD BOB

I got a 302 with heads cam headers and msd ign and i put a holley 750 on it and it seems to be loading up. Any help on if i should change jets or something?

What do you mean by loading up??? Bogging, backfireing. Check you plugs they will usually tell you what you need to do.

BAD BOB · 03-03-2009, 09:57 PM

its a new motor and all i have done is let it sit and run just to make sure everything it working good. At first it smelled a little rich so i tryed adjusting it which helped out but all the sudden at the end of the day i was messing with it and it started to choke out. It would crank right back up but seemed like the plugs were a little fouled so i would rev to clean them up then it sounded good then all the sudden do the same. I know it was a little rich a first but now it seems to be real rich.

slowgreen99 · 03-03-2009, 10:03 PM

shoot that bitch. Itll help lean it out

WWhittle · 03-03-2009, 10:19 PM

Quote:

Originally Posted by BAD BOB

its a new motor and all i have done is let it sit and run just to make sure everything it working good. At first it smelled a little rich so i tryed adjusting it which helped out but all the sudden at the end of the day i was messing with it and it started to choke out. It would crank right back up but seemed like the plugs were a little fouled so i would rev to clean them up then it sounded good then all the sudden do the same. I know it was a little rich a first but now it seems to be real rich.

you adjust the floats?

BAD BOB · 03-03-2009, 10:22 PM

all i adjusted was the fuel mixture screw. The carb was on a stock 302 and ran fine but was rich so the man got a 600 so i fugured with the mod it would work ok

BAD BOB · 03-03-2009, 10:23 PM

Quote:

Originally Posted by streetsweeper

you adjust the floats?

looking in the sight glass it looks like the fuel may be a little low before it is too high

05Saleen · 03-03-2009, 10:31 PM

That is your idle mixture screw! Use a vacuum guage to set. Set your float level to the bottom of the site glass and use a vac guage to set your idle adj. adj till you have the highest vacuum reading and run for a while and ck. your plugs. If they are wet then you need to go to smaller jets...

WWhittle · 03-03-2009, 10:32 PM

I dont see these getting diagnosed over the internet.

BAD BOB · 03-03-2009, 10:32 PM

right and thats all its been doing and all the sudden it started running rich again i guess. I going to maybe try some new plugs and see if will help out

05Saleen · 03-03-2009, 10:37 PM

See the post 3 above. Slow typing.....

05Saleen · 03-03-2009, 10:50 PM

If you can catch me on the weekend probably on a sunday. Give me a call and I can probably help you diagnose it or fix it.

BAD BOB · 03-03-2009, 10:50 PM

Quote:

Originally Posted by 05Saleen

That is your idle mixture screw! Use a vacuum guage to set. Set your float level to the bottom of the site glass and use a vac guage to set your idle adj. adj till you have the highest vacuum reading and run for a while and ck. your plugs. If they are wet then you need to go to smaller jets...

thanks that will hopefully get me somewhere

05Saleen · 03-03-2009, 10:52 PM

Read previous post.

Pesce Nero · 03-03-2009, 10:58 PM

where is timing at?, there is more than one A/F screw, i would assume you ment the curb idle screw that you were messing with. if the carb has been sitting, i would kit it.

jets have no effect on what a carb does at idle nor does a power valve unless its blown out then you can get fuel dripping right into the plenum causing a rich mixture. if throttle plates are open to far, you will also have a problem with a carb pulling fuel from the transfer circuit.

how big a cam in the engine?

BAD BOB · 03-03-2009, 11:02 PM

when changing jets how much should you change a one time?

BAD BOB · 03-03-2009, 11:04 PM

Quote:

Originally Posted by SIXPACKGUT

where is timing at?, there is more than one A/F screw, i would assume you ment the curb idle screw that you were messing with. if the carb has been sitting, i would kit it.

jets have no effect on what a carb does at idle nor does a power valve unless its blown out then you can get fuel dripping right into the plenum causing a rich mixture. if throttle plates are open to far, you will also have a problem with a carb pulling fuel from the transfer circuit.

how big a cam in the engine?

its like 520 or so. I dont know exactly

05Saleen · 03-03-2009, 11:12 PM

I don't think you will be able to diagnoss this over the computer!

03-03-2009, 06:38 PM	#1
BAD BOB Senior Member Join Date: Mar 2008 Location: SUMMERVILLE Posts: 3,681	302 carb help I got a 302 with heads cam headers and msd ign and i put a holley 750 on it and it seems to be loading up. Any help on if i should change jets or something?

03-03-2009, 06:48 PM	#3
LXtasy Senior Member Join Date: Dec 2006 Location: Summerville, SC Posts: 9,564	Which heads and cam? Dp or vacuum secondaries? Transmission? rear gear? 750 could be to much carb IMO. __________________

03-03-2009, 10:03 PM	#6
slowgreen99 Senior Member Join Date: Jan 2008 Location: Summerville Posts: 7,740	shoot that bitch. Itll help lean it out __________________ M.R.E. Bad Bob Motorsports

03-03-2009, 10:31 PM	#10
05Saleen Senior Member Join Date: Dec 2006 Location: Goose Creek, SC Posts: 3,159	That is your idle mixture screw! Use a vacuum guage to set. Set your float level to the bottom of the site glass and use a vac guage to set your idle adj. adj till you have the highest vacuum reading and run for a while and ck. your plugs. If they are wet then you need to go to smaller jets... __________________ 05 Saleen, 91 Mustang LX, 99 Lightning Last edited by 05Saleen; 03-03-2009 at 10:36 PM.

03-03-2009, 10:37 PM	#13
05Saleen Senior Member Join Date: Dec 2006 Location: Goose Creek, SC Posts: 3,159	See the post 3 above. Slow typing..... __________________ 05 Saleen, 91 Mustang LX, 99 Lightning

03-03-2009, 06:46 PM	#2
WWhittle Senior Member Join Date: Apr 2008 Location: Mt. Pleasant, SC Posts: 3,899	what jets are in it and what is it doing?

03-03-2009, 09:57 PM	#5
BAD BOB Senior Member Join Date: Mar 2008 Location: SUMMERVILLE Posts: 3,681	its a new motor and all i have done is let it sit and run just to make sure everything it working good. At first it smelled a little rich so i tryed adjusting it which helped out but all the sudden at the end of the day i was messing with it and it started to choke out. It would crank right back up but seemed like the plugs were a little fouled so i would rev to clean them up then it sounded good then all the sudden do the same. I know it was a little rich a first but now it seems to be real rich.

03-03-2009, 10:22 PM	#8
BAD BOB Senior Member Join Date: Mar 2008 Location: SUMMERVILLE Posts: 3,681	all i adjusted was the fuel mixture screw. The carb was on a stock 302 and ran fine but was rich so the man got a 600 so i fugured with the mod it would work ok

03-03-2009, 10:32 PM	#11
WWhittle Senior Member Join Date: Apr 2008 Location: Mt. Pleasant, SC Posts: 3,899	I dont see these getting diagnosed over the internet.

03-03-2009, 10:50 PM	#14
05Saleen Senior Member Join Date: Dec 2006 Location: Goose Creek, SC Posts: 3,159	If you can catch me on the weekend probably on a sunday. Give me a call and I can probably help you diagnose it or fix it. __________________ 05 Saleen, 91 Mustang LX, 99 Lightning

03-03-2009, 10:52 PM	#16
05Saleen Senior Member Join Date: Dec 2006 Location: Goose Creek, SC Posts: 3,159	Read previous post. __________________ 05 Saleen, 91 Mustang LX, 99 Lightning

03-03-2009, 10:58 PM	#17
Pesce Nero Senior Member Join Date: Jul 2008 Posts: 2,680	where is timing at?, there is more than one A/F screw, i would assume you ment the curb idle screw that you were messing with. if the carb has been sitting, i would kit it. jets have no effect on what a carb does at idle nor does a power valve unless its blown out then you can get fuel dripping right into the plenum causing a rich mixture. if throttle plates are open to far, you will also have a problem with a carb pulling fuel from the transfer circuit. how big a cam in the engine?

03-03-2009, 11:02 PM	#18
BAD BOB Senior Member Join Date: Mar 2008 Location: SUMMERVILLE Posts: 3,681	when changing jets how much should you change a one time?

03-03-2009, 11:12 PM	#20
05Saleen Senior Member Join Date: Dec 2006 Location: Goose Creek, SC Posts: 3,159	I don't think you will be able to diagnoss this over the computer! __________________ 05 Saleen, 91 Mustang LX, 99 Lightning