Re-jetting the Solex |
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Steelyard Blues
Member Joined: 09 Oct. 2017 Location: Reno, NV Status: Offline Points: 1483 |
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Posted: 10 Jan. 2021 at 2:13am |
Like many of us, my Jeep tends to run hot. At lower speeds,
she stays at 160 but any prolonged time over 40 MPH tends to bring the temperature
up to 180+. After one prolonged high-speed drive towing my M416, I pulled the
plugs and noticed they were absolutly clean and white. Concerned that the
higher temps may be due to a lean burn, I decided to re-jet the Solex. Standard Solex settings for the L134 are a 127.5 main jet and
a 190 air correction jet. Economy setting is a 115/195. Standard Solex settings for the F134 are a 140 main and a 160
air correction. The economy settings are the same as the standard L134,
127.5/190. I decided to try the F head settings, 140/160. I was already
running a richer 132.5/190 combination. I know the F head makes a bit more
power but, since the displacement is the same, the settings cannot be too far
off and are a good reference point, The jets are easy to replace without removing the carb. All
you need is a wide blade screw driver and a 12mm wrench. The main jet is on the
front of the carb, facing the radiator, and next to the accelerator pump. Remove
the 12mm brass jet retainer and unscrew the main jet from it. The air correction
jet is in the throat of the carb. Remove the air horn extension to access it. I
suggest putting some paper towels in the throat of the carb to prevent the jet
or anything else falling into the carb. The jet is screwed into a tube. The
tube may spin as you try to unscrew the jet. Use a pair of needle nose pliers
to hold the tube and unscrew the jet. Inside the outer tube is brass emulsion
tube with six small holes in it. If you have a dental pick or similar tool, you
might want to remove the emulsion tube and check for obstructions. It took me a while to figure out where to find the correct
replacement jets, especially when you tell the parts guy that you are working
on a 1947 Jeep. I got several responses from Solex part providers who had no
idea about the M32-PBIC carb. The main jets are from EMPI with part numbers 43-5140-7 (140
main) 43-5132-7 (132.5 main). I got these for $10 each with shipping off eBay.
Supplier was Moore Parts Source, 700 Van Buren St, Unit A, Placentia, CA. eBay
seller: Moorepartssource. The air correction jets are also used by Mikuni. I also got
these from eBay for $3 each plus shipping. The 160 part number is B42/56/160. I
picked up a 170 and a 180 also. Supplier was www.nichecycle.com.
eBay seller niche-cycle. I have not been able to do a prolonged high-speed drive. It
is January and my Jeep doesn’t have a top. I did take it on a couple mile street
drive and for a few minutes in the hills where I kept her revs up in 4L. She
ran very well with good power and temps at 160 the entire time. A little
difficult to gauge the outcome since ambient temperature was 45 and the cold
air is a bit more dense. Upon return, I noticed my idle speed was off and the mixture
was fairly rich. I’m not sure why she was set so rich, I usually have her idling
pretty well. Once I leaned her back out, she idled very smooth (NOTE the main
jet does not generally operate below 1,500-2,000 RPM). When I pulled a plug, I
did not get a good reading because of the rich idle. The plug was black. I plan
to do further tuning once the outside temperatures are warmer. Come summertime,
I will be able to see if there are any affect on coolant temperature. Since Reno
is at 4,500, I may have to try a 135 or 132.5 main jet with a 180 or 170 air
correction jet. For those running a Solex and do trips to higher elevations,
you might want to consider bringing a set of lean or economy jets with you. Micah See attached: |
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1947 CJ2A 106327, Engine J109205, Tub 97077. Luzon Red
https://www.thecj2apage.com/forums/steelyard-blues_topic41024_post397981.html?KW=micah+movie#397981 1965 Johnson Furnace Company M416 #6-1577 |
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aboyandhisdog
Member Joined: 10 June 2011 Location: Fort Collins Status: Offline Points: 465 |
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Thanks for this, Blues - very nice write up! I have been running the 115 main jet in my L head for years between 8500' and 12,500' and it is PERFECT.
But I didn't know I could get an air correction jet. I see that Niche Cycle has them in a 200 - up from the standard 190. They don't have a 195. What benefit or change do you think I would see going to a 200? (I'm not really sure what the air correction jet does.) Might just order one (ac jet) and see how it affects the running, but would love to learn more about what it does. BTW, I really like my Solex. Most guys don't take the time to get to know them. There are a couple of adjustments that I have made to dial them in, but I don't have nearly the issues 'in the field' that the Carter guys do.
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Mark W.
Member Sponsor Member Joined: 09 Nov. 2014 Location: Silverton, OR Status: Offline Points: 7923 |
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I think 160 degrees is not warm enough your running a cold engine which also causes problems.
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Chug A Lug
1948 2A Body Customized 1949 3A W/S 1957 CJ5 Frame Modified Late 50's 134L 9.25"clutch T90A D18 (1.25") D44/30 flanged E-Locker D25 5.38 Since 1962 |
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Steelyard Blues
Member Joined: 09 Oct. 2017 Location: Reno, NV Status: Offline Points: 1483 |
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Tom,
I have no complaints with the Solex. I'm in no rush to replace it since I plan to stick this Holley on there after a rebuild with cam and headers: This VW site has a good write up as to what the air correction jet does: Mark, 160 is the stock thermostat. At idle and up to about 40 MPH she will run around 160. Above 40 MPH, my Jeep runs between 160 and 180. My issue is under heavy load or prolonged drives over 40. I have a couple stretches that I regularly drive a couple miles at 50-55. This is where I see my temps spike. With the excessively clean plugs, I'm experimenting to see if I have a high speed lean condition resulting in the excessive heat. Micah
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1947 CJ2A 106327, Engine J109205, Tub 97077. Luzon Red
https://www.thecj2apage.com/forums/steelyard-blues_topic41024_post397981.html?KW=micah+movie#397981 1965 Johnson Furnace Company M416 #6-1577 |
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aboyandhisdog
Member Joined: 10 June 2011 Location: Fort Collins Status: Offline Points: 465 |
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That "jets" page was a really good read. Thanks!
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Steelyard Blues
Member Joined: 09 Oct. 2017 Location: Reno, NV Status: Offline Points: 1483 |
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Tom,
I'm glad to hear you found this and the link useful. You never know when you throw something out there. Micah
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1947 CJ2A 106327, Engine J109205, Tub 97077. Luzon Red
https://www.thecj2apage.com/forums/steelyard-blues_topic41024_post397981.html?KW=micah+movie#397981 1965 Johnson Furnace Company M416 #6-1577 |
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