Carb problem ?
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Senior User
Joined: Mar 2004
Posts: 104
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From: UK
Carb problem ?
Guys,
as you know from my repeated questions of random-ness ive just done a top end rebuild on my 360. heads were skimmed and rebuilt, new valves and seat seats etc...
well, after my first TIMING issue, the truck now fires up and runs, but it runs real fast.. so a back the timing off (dizzy goes counter clockwise ?) and it slows down...
Now my problem is, when i give it a rev then come off it, the revs drop down to 1000 then slowly fall off 700......500...300.....splutter .... dead..
It was doing this kind of thing before so im thinking its the carb. THere are 2 white screws with limiters on the front of the motorcraft 2bbl. What do these do and how do i stop it running like this ???
Many thanks guys,
EDGE
as you know from my repeated questions of random-ness ive just done a top end rebuild on my 360. heads were skimmed and rebuilt, new valves and seat seats etc...
well, after my first TIMING issue, the truck now fires up and runs, but it runs real fast.. so a back the timing off (dizzy goes counter clockwise ?) and it slows down...
Now my problem is, when i give it a rev then come off it, the revs drop down to 1000 then slowly fall off 700......500...300.....splutter .... dead..
It was doing this kind of thing before so im thinking its the carb. THere are 2 white screws with limiters on the front of the motorcraft 2bbl. What do these do and how do i stop it running like this ???
Many thanks guys,
EDGE
Postmaster
Joined: Nov 2002
Posts: 3,447
Likes: 1
From: Littleton, CO
Well... You do not want to set your idle by adjusting your timing. Familiarize yourself with the datails of the carb and it's adjustments. Then set your timing correctly and start adjusting your carb. You probably need to rebuild the carb before you go through this as you state you were having problems previously. Adjust the air/fuel needles and idle as necessary to make all the goodies work together. No sence in putting junk back on a refreshed motor.
--Mike
--Mike
Junior User
Joined: Feb 2004
Posts: 91
Likes: 0
From: Ohio
do you have a whistling noise before the stall? just wondering if mabey you have a vac leak somewhere... still got on the carb spacer with the nipple out the front under the carb? put your thumb over that vac nipple if its not already plugged... mabey the plug (hose and bolt) is missing? fell off during rebuild? i know that this nipple unplugged will cause the stall. just an idea.
Cargo Master
Joined: Apr 2004
Posts: 2,574
Likes: 4
From: Golden, CO
All true! If you have the money to spend, a good choice to make.
Be aware that even a new carb needs to be set up and tuned.
I get the impression that you haven't done much with carbs yet. The ole 2bbl is a good one to learn on: simple, cheap, and easy to replace if you find a cracked/broken/worn out casting.
The last time I rebuilt my 2bbl I spent $10 on the kit and $15 on a gallon of Chem-Dip (reuseable). I already had compressed air, a vacume guage, and a manual to refresh my memory. If you don't have compressed air, aerosol cleaner is effective for "chasing" the passages after rinsing.
The best part is that I had the beast parked back on the street before my wife returned home.
For less than $100 you could be driving it this weekend and have a better understanding of how all the parts-n-parts work together.
Just some food for thought, Mike
Be aware that even a new carb needs to be set up and tuned.
I get the impression that you haven't done much with carbs yet. The ole 2bbl is a good one to learn on: simple, cheap, and easy to replace if you find a cracked/broken/worn out casting.
The last time I rebuilt my 2bbl I spent $10 on the kit and $15 on a gallon of Chem-Dip (reuseable). I already had compressed air, a vacume guage, and a manual to refresh my memory. If you don't have compressed air, aerosol cleaner is effective for "chasing" the passages after rinsing.
The best part is that I had the beast parked back on the street before my wife returned home.
For less than $100 you could be driving it this weekend and have a better understanding of how all the parts-n-parts work together.
Just some food for thought, Mike
Thread Starter
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Senior User
Joined: Mar 2004
Posts: 104
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From: UK
good call, I haven't got the first clue about carbs, I come from a totally fuel injected throttle body background. I spend everyday just praying that the carb will carry on doing its job... there's no ecu for me to plug in to here ?!?!?!
from what can see on the carb there are only the 2 white screws to mess with, now all i gotta do is find out what they do, anyone ?
EDGE
from what can see on the carb there are only the 2 white screws to mess with, now all i gotta do is find out what they do, anyone ?
EDGE
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Post Fiend
Joined: Mar 2004
Posts: 6,056
Likes: 8
From: Union, Washington
The two screws on the down low on the front of the base plate of the carb under the float bowl angling out slightly are the mixture adjustment screws; in (clockwise) to lean the mixture out (couterlockwise) to richen. To start screw them in while counting turns until lightly seated then back out to 1 1/2 turns. They should have been close to that to start with. Then slowly turn either one in until engine stumbles the back out past starting point un til it starts to slow down the back to half way between those two points. Do the other screw. To adjust Idle speed make sure engine is warm and choke is off. Then on left side of carb(drivers side) is a screw on the throttle linkage. In will speed up, out will slow down. Can be adjusted prior to carb mixture adjust if rpms are above 800 (600 is better). Before you adjust carb set ignition timing to spec. This aint rocket science, real basic stuff. Any shop manual will have all the info you need. No money for a manual, then library will will have one. Go in and read, if need be copy a few pages and go do it.
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Senior User
Joined: Mar 2004
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From: UK
thanks for the advice dude, but those 2 screws only turn about 7/8 of a turn, total. theres a limiter stopping it from turning a whole turn ? maybe thats all the adjustment i have ?
time to go read a book....
assuming a library over here in the uk carries a book on motocraft carb tuning
EDGE
time to go read a book....
assuming a library over here in the uk carries a book on motocraft carb tuning
EDGE
Post Fiend
Joined: Mar 2004
Posts: 6,056
Likes: 8
From: Union, Washington
Originally Posted by Edge Motorsport
thanks for the advice dude, but those 2 screws only turn about 7/8 of a turn, total. theres a limiter stopping it from turning a whole turn ? maybe thats all the adjustment i have ?
time to go read a book....
assuming a library over here in the uk carries a book on motocraft carb tuning
EDGE
time to go read a book....
assuming a library over here in the uk carries a book on motocraft carb tuning
EDGE
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