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Autolite & Motorcraft Carburetor Main Jet

Autolite & Motorcraft Carburetor Main Jet

Your Price:$4.50
In Stock
Part Number:120-4

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Motorcraft Jets

Motorcraft main jets, 1100, 1101, 2100, 2150, 4100, 4300, 4350. Priced per each. These are ordered by size .048, .058, etc. You will find the current jet number stamped on the top of the jet. Order by selecting the jet size from the drop down list. Price is per jet.

These are 5/16" on the threaded end.

Some of the older 2100 & 4100 Autolites are much smaller. Typically 1963 and older (assuming you are 100% sure you know the year of your carb.). This type of 4100 will probably have a plastic lever going to the secondary diaphragm. This type of 2100 & 4100 jet can be found here.

  • Made in USA
  • Number Stamped on Top

Your old jet may have the size stamped on the top or side. 50f=.050, 50=.050

Motorcraft 2100 Jet Sizes

Jet Testing
To determine if you have the correct jets in your carburetor, operate your vehicle for 20 minutes at sustained speeds. Stop and pull a plug. Gray - Good, Black - move down one jet size, White - move up one jet size. Do it all over again until you get a gray plug.

This assumes your engine and electrical system is in good running order.

Autolite 1100 Main Jet

Autolite 1100 Jet

5 Stars
Best carb parts
Love it!!! They came super fast and arrived much sooner than expected. Dropped them in the carb in about 15 min and solved the stumbling problem completely. Nice quality and it's great to know I can get the parts I need that are otherwise unavailable in my area. Old cars never die, thanks for helping keep me on the road.
Did you find this helpful?  2 of 2 Found Helpful
Reviewed by:  from Tennessee. on 5/25/2015
5 Stars
66 Mustang GT owner
In trying to improve MPG I tried various sizes of Jets from Mike's and they fit great.
Did you find this helpful?  1 of 1 Found Helpful
Reviewed by:  from cypress cal. on 7/19/2015
5 Stars
Awesome Jets
Shipping was faster then expected and I ordered during the week overlapping Canada day and Independence day. I ordered 6 sets to help fine tune my carb post swap and once these arrived I was impressed with quality and the fact they could be tightened and removed multiple times without getting chewed up. These jets aren't readily available here and when putting a 2100 off a 390ci v8 (jetted 54) goes on 150ci L4 (final jet choice 45) you need jets. Great product and better service!!
Did you find this helpful?  1 of 1 Found Helpful
Reviewed by:  from Canada. on 7/9/2015
5 Stars
jets were installed and work as advertised. Good product.
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Reviewed by:  from San Antonio. on 11/10/2015
3 Stars
OK, but poor stamp quality
The two jets I received were OK. The only problem was that the stamp quality was poor, requiring a magnifying glass to make out the second digit. It was not completely formed. All the other items were packaged well, marked appropriately, and appear to be very good quality. I recommend Mike's Carburetor parts in general. The have a great selection, so you can get more at one vendor.
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Reviewed by:  from Kentucky. on 7/14/2015
4 Stars
Clean and very we'll made! Shiny and helped my old ford pass smog. But theads would not match my carb so I had to tap out new ones
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Reviewed by:  from Shafter ca. on 6/7/2015
5 Stars
As advertised
Ordered a set of 2 for the 2100. Improved performance by jetting down. Got here quick, as usual. Very happy with my purchase.
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Reviewed by:  from New Mexico. on 5/26/2015
5 Stars
Mike fast service parts were all there as ordered if you need tec info mike takes time out to talk to you as he did me Hes got my vote
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Reviewed by:  from Ky. on 5/17/2015
5 Stars
Very nice quality jets, fit my carburetor threads exactly. I read that modern fuel might require a somewhat larger jet than the original from 50 years ago, so I ordered a set 1 size larger to see what would happen. The car is running silky smooth now, but I also put in a premium carb kit at the same time, so I don't really know if it helped or hurt anything.
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Reviewed by:  from Phoenix, AZ. on 5/4/2015
5 Stars
The Dude
I ordered these Motorcraft jets to lean out my fuel mixture on my CJ7 to pass the good ol' CA emissions. Mike sent the parts very quickly in time for me to rebuild my carb and make my trip!
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Reviewed by:  from Apple Valley, CA. on 4/11/2015

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