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carburetor re-build or new

bax

Contributor
Old Member
Joined
Aug 22, 2005
Messages
14,490
Rebuild it. it is easy. if you dont know how , well now is a good time.
 

thirdtime

Contributor
Full Member
Joined
Jan 27, 2009
Messages
252
X2 on the rebuild. Just did mine this weekend, huge difference. If I didn't let it soak in the cleaner, I could have been done in under and hour.
 

bluemonday

Sr. Member
Joined
Mar 16, 2010
Messages
690
Loc.
South Louisiana
I rebuilt one a year ago and it ran better. I just bought a new Holly 500cfm 2 Barrel, pers like a kitten. Well worth the money. My 2 cents.
 

ft bronc

Jr. Member
Joined
Feb 25, 2008
Messages
143
Loc.
Greater Cincinnati
I rebuilt one a year ago and it ran better. I just bought a new Holly 500cfm 2 Barrel, pers like a kitten. Well worth the money. My 2 cents.

This story is not uncommon. The Motorcraft 2bl is a good carb & easy to rebuild, but often after rebuilding one that's 40 years old, they just don't seem to work 100% as original. They've worked OK, but not great. I've chased them around quite a bit and usually never find exactly what's wrong. So far I've lived with them @ 90% because new Holleys are a little pricey.
 

bmc69

Contributor
Bronco Guru
Joined
Jun 11, 2004
Messages
11,849
This story is not uncommon. The Motorcraft 2bl is a good carb & easy to rebuild, but often after rebuilding one that's 40 years old, they just don't seem to work 100% as original. They've worked OK, but not great. I've chased them around quite a bit and usually never find exactly what's wrong. So far I've lived with them @ 90% because new Holleys are a little pricey.

Some observations on teh Motorcraft from an old guy that once ran a carb rebuild shop; there are basically four or five key things that I learned about rebuilding those that are easy to miss:

1. The power valves that come in the average rebuild kit are quite often junk and at the least too weak. I always used Ford or Holley power valves in the ones I rebuilt. In fact, I would stock and use a power valve that was, on average, about 2.0" hg higher in value than what the factory ones were supposed to be. Customers would often remark that the rebuilt carb seemed "more responsive" ..and that was why.

2. Many people don't install a new float when they rebuild the carb. The composite float must always be replaced, no matter how 'good' you think it looks.

3. The proper function of the vacuum choke pulloff is important; make sure yours is working perfectly and replace if not. Some kits will include the older style that is mounted up next to the air horn. Side mount pull-offs found on later 2150 carbs are never included in the rebuild kits.

4. The brass emulsion tubes (about 1/4" diameter and a couple inches long ...with all the small holes in them) that are connected to and that feed the annular discharge rings in the boost venturi assembly become brittle with age and will crack, sometimes they crack in multiple places. The cracks can be very subtle; a magnifying glass should be used to inspect those two little tubes.

5.The air supply tubes that run down the center of those emulsion tubes must always be cleaned out with a torch tip cleaner; the ID is just too small to count on carb cleaner and compressed air to do that job.
 

Jeff76

Sr. Member
Joined
Dec 23, 2011
Messages
638
Loc.
Alpharetta GA
Wow. Thanks BMC69. There are little nuggets of info from the smart folks on this site that just can't be found in a service manual, and that post is an example. I just rebuilt my 2100, and it seems to be working OK, but I'm clipping this one for future reference!
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
The Bronco 2150 had the float damper spring in the carb. this is a rare piece that a new or rebuilt carb wont come with. In the above repair manual look at the off road modifications listed.
 

OldBarnBronco

Jr. Member
Joined
Nov 25, 2009
Messages
87
I'm definightly chipping in on this thread too! Not sure if or when I'll ever go EFI so I'll go this route for sure. Thanks!!
 

jon705

Full Member
Joined
Jun 22, 2005
Messages
166
I've rebuilt mine several times over the years and while it's ran better afterward still never ran quite like it should have- lots of cranking to get her to fire up, surging at idle.

A few weeks ago I sent mine to Guaranteed Carburetors in Largo, FL and they did a fantastic job. They replaced all internal parts, linkage, and tuned it so that it was ready to bolt on and go. It looks brand new and now with a short turn of the key she fires up and runs like new. Definitely worth the money.
 

Show Links

Full Member
Joined
Jun 30, 2013
Messages
298
Loc.
Bakersfield
Best Carb Kits

I would like to try rebuilding my Autolite 2100. What have you found to be the best quality rebuild kit for this carburetor.

Thanks for any help,

Rob
 

matt w

Bronco Guru
Joined
Jun 12, 2007
Messages
2,798
I've rebuilt mine several times over the years and while it's ran better afterward still never ran quite like it should have- lots of cranking to get her to fire up, surging at idle.

A few weeks ago I sent mine to Guaranteed Carburetors in Largo, FL and they did a fantastic job. They replaced all internal parts, linkage, and tuned it so that it was ready to bolt on and go. It looks brand new and now with a short turn of the key she fires up and runs like new. Definitely worth the money.

I have been watching this thread and this does not sound like a bad suggestion. Was it really only 158.00??
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,195
I used a Hygrade Products kit on a 4100 recently and found it to be excellent. Most of these carbs have been rebuild several or many times so check the diagrams to look for missing parts. The float damper spring is a good example. Many re-builders both professional and amateur leave out parts they don't understand or seem too much trouble. Walker Products sells all these parts including new floats for reasonable prices. Buying a new carb means buying a new and different carb. These won't be dialed in to your engine like the original, at least not without a lot of work and carb knowledge. A Holley 2300 350cfm is about the only choice for 2bbl applications. These require a lot more tinkering and maintenance than the 2100-2150s and are unlikely to ever work as well. The tips bmc69 listed and a quality kit are likely to yield a better on road/ off road carb than you can get from Holley.
 
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