Solex Carb

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dave in pa.
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Solex Carb

Post by dave in pa. » Tue Dec 30, 2003 3:48 am

Hi all,
If this question has been beat to death...please forgive me.

What are the pros and cons of using the Solex replacement carb? Starting in hot and cold weather? Starting with a hot or cold engine? Acceleration? Idle quality? Power? Torque? How does it compare with other options?

Any user comments or complaints?

Thanks,
Dave


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Post by Bob N » Tue Dec 30, 2003 5:02 am

Dave I use to be Mr. Solex around here. :lol: The Solex is a good little carb with some idiosyncracies to consider.

First, it is an incorrect choice for the WW2 jeep (except in a motorpool jeep very late WW2 ETO (limited amounts of jeeps that were rebuilt by the French and USED by the US Army)) Enough jeeps used this method to warrant an article in Army Motors (WW2 era) magazine.

If you go trying to start a Solex equipped jeep like you would a Carter you will be lucky if you EVER get it started. NEVER touch the throttle when starting the jeep. Pull out the "starter", well, we call it a choke. Attempt to start. If it fails to start then give it a press or two on the foot throttle. Once it starts you can adjust the "choke" and throttle. Until I understood this I had a hell of a time starting the jeep.

For details on this and more you might like to look over my Solex carbpages. It has the starting instructions for various operational conditions that you may find helpful.

At first I thought acceleration, etc had all improved with the introduction of the Solex to my engine. However, once warm weather had returned, my old problems of apparent flooding returned. It was then that I discovered that my fuel pump put out way too much pressure for the Solex. So I had to install a fuel pressure regulator. Once that was installed the jeep calmed down. But that got me to thinking. This was the SAME problem I was having with a newly rebuilt Carter that I had taken off in disgust a few months earlier....so I swapped the Carter back in and haven't looked back.

The Solex is a good temporary carb. I found that I could get the proper adapter (fuel line SAE to special fitting Metric)...so I followed the advice of JP Magazine and got one that was close and just jammed it in with teflon tape...no leaks but not the best way to go. One last Solex thing. DO NOT USE the cheap thin gasket that usually comes with this carb on the jeep. Get a real jeep gasket with the metal V disperser. The jeep will love you for it.


Other options? Well....other carbs have been tried, especially in the 50s with modified manifolds, dual carbs. JP Magazine fitted FUEL INJECTION but for $800 plus you don't get much in the way of improvements. I guess for rock crawling it has the improvement of not really caring what the engine angle is (less fuel starvation at extremes).

Better than a replacement carb, I added electronic ignition to my Frankenjeep(tm) some time ago and this was a great improvement. It starts quickly. No need to screw around with gaps (except on the sparkplugs) ever again. The engine seems to run smoother. Stalled out in a creek in October, hit it going to fast, engine started right up. Seems to be less worry about wet ignition parts. But no proof in that.

Bottom line? Stick with the Carter. But if you already have bought the Solex it will work fine...just understand how it works.
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Post by Don C » Tue Dec 30, 2003 9:26 am

Dave,

To add to Bob N's comments...I have switched to Solex a year ago and never looked back. I had my Carter WO rebuilt when I got the jeep and added a fuel pressure regulator at that time. I still had problems with flooding, stalling, and very hard starting. My wife called my jeep "Old Stinky" because of the rich gassy smell of the exhaust.

I put on the Solex and the jeep starts easy every time, runs much leaner, and is much quieter with increased pick up and power.

According to a friend who builds drag and hot rod engines, the Carter WO is the worst carb design he ever saw.

Pointers:

You must add a fuel pressure regulator before the carb and set it to 2 PSI.

You will have to rework the fuel line to fit the new carb. As part of the fitment I added a small, modern in line fuel filter.

Make sure you check with a good mechanic or auto parts store to get the proper fittings.

Be sure to properly torque the banjo bolt going into the carb. I found the banjo bolt loosens and weeps at the fiber gasket. You must check that it is snug as often as you check your tires and coolant level.

Good Luck,

Don C 8)

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Post by Steve Livingston » Wed Dec 31, 2003 6:46 am

Bob N,

That was a great explaination of how to start the jeep with a Solex carb. Mine came with it and, after several months, think I have figured it out....pull the choke first....if no fire, pump 2 times.

Bob, is there a secret as to starting it up after stopping for a few minutes? Most of the time it starts but other times it does not (or acts like it is not going to start). What is considered a "cold" start?

I have a '85 F150 that has a carb and it pretty much is the same. It will flood if you give it too much fuel after stopping for a few minutes.. BUT, the 12 volt system allows for mistakes in my opinion. You can just keep on cranking and making adjustments.

This make since? Or, is this another trial by error situation?

Thanks for all the feedback you give.

Steve

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Pressure regulator for Solex

Post by mpitts » Wed Dec 31, 2003 8:13 am

Where can a pressure regulator be found to use with the Solex carb. I have just purchased?

Thanks for the hlep

Martin
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Post by Bob N » Wed Dec 31, 2003 12:29 pm

I just went to the local auto parts house and told them I wanted a manually adjustable fuel pressure regulator. It was less than $20, if I remember correctly. However, I looked on the NAPA website and I found the "NAPA" labeled regulator...looks just the same except for the label.

Fuel Pressure Regulator on the NAPA site.

Image
Adjusts from 1 - 5 lbs of pressure. Worked for me and the Solex and continues to work for me and my Carter. One of these days I guess I will rebuild that fuel pump myself.

Item#: BK 7302367

Price: $ 29.99
tax and shipping not included

Contact customer service for ordering details.


Attributes:
Attributes: Fuel Pressure Regulator - Adjustable
PSI Range: 1-5 PSI in 1/2 PSI Increments
Hose Size: 5/16''
Additional Contents: 1 Regulator, 2 Fittings, 2 Hoses & 4 Clamps
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Post by Mighty Eighth » Fri Jan 02, 2004 8:35 am

I was never happy with the new Solex I got and now it sits on a shelf. I found it hard to start and the performance, once started, was not impressive. Now it sits on my shelf of carbs waiting its turn to be traded for something useful. :wink: gary
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Post by Richard Starr » Sat Jan 03, 2004 4:21 pm

My jeep came 2 years and 7000 miles ago with a Solex, and I haven't changed it. I don't have a pressure regulator.

Steve - to start when warm, just hold the gas pedal down 1/2 way. Should fire up no problem.
Richard Starr
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Post by Guest » Sun Feb 29, 2004 8:07 pm

I too have a Solex....I choke it to start when cold and may be 2 pumps on the pedal.
Once warm or even after sitting for hours it still starts right up and purrs....I did convert to 12v and love it.

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Re:

Post by Joe Gopan » Wed Dec 01, 2010 3:08 am

Bob N wrote:Dave I use to be Mr. Solex around here. :lol: The Solex is a good little carb with some idiosyncracies to consider.

First, it is an incorrect choice for the WW2 jeep (except in a motorpool jeep very late WW2 ETO (limited amounts of jeeps that were rebuilt by the French and USED by the US Army)) Enough jeeps used this method to warrant an article in Army Motors (WW2 era) magazine.

If you go trying to start a Solex equipped jeep like you would a Carter you will be lucky if you EVER get it started. NEVER touch the throttle when starting the jeep. Pull out the "starter", well, we call it a choke. Attempt to start. If it fails to start then give it a press or two on the foot throttle. Once it starts you can adjust the "choke" and throttle. Until I understood this I had a hell of a time starting the jeep.

For details on this and more you might like to look over my Solex carbpages. It has the starting instructions for various operational conditions that you may find helpful.

At first I thought acceleration, etc had all improved with the introduction of the Solex to my engine. However, once warm weather had returned, my old problems of apparent flooding returned. It was then that I discovered that my fuel pump put out way too much pressure for the Solex. So I had to install a fuel pressure regulator. Once that was installed the jeep calmed down. But that got me to thinking. This was the SAME problem I was having with a newly rebuilt Carter that I had taken off in disgust a few months earlier....so I swapped the Carter back in and haven't looked back.

The Solex is a good temporary carb. I found that I could get the proper adapter (fuel line SAE to special fitting Metric)...so I followed the advice of JP Magazine and got one that was close and just jammed it in with teflon tape...no leaks but not the best way to go. One last Solex thing. DO NOT USE the cheap thin gasket that usually comes with this carb on the jeep. Get a real jeep gasket with the metal V disperser. The jeep will love you for it.


Other options? Well....other carbs have been tried, especially in the 50s with modified manifolds, dual carbs. JP Magazine fitted FUEL INJECTION but for $800 plus you don't get much in the way of improvements. I guess for rock crawling it has the improvement of not really caring what the engine angle is (less fuel starvation at extremes).

Better than a replacement carb, I added electronic ignition to my Frankenjeep(tm) some time ago and this was a great improvement. It starts quickly. No need to screw around with gaps (except on the sparkplugs) ever again. The engine seems to run smoother. Stalled out in a creek in October, hit it going to fast, engine started right up. Seems to be less worry about wet ignition parts. But no proof in that.

Bottom line? Stick with the Carter. But if you already have bought the Solex it will work fine...just understand how it works.
BTT :wink:
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Re: Solex Carb

Post by Tim52 » Fri Dec 03, 2010 6:21 pm

I have had the same flooding issue with mine. My fuel pump is 4-5 psi. I just purchased a Holly pressure 12-804 Fuel Pressure Reducer that I have not yet installed. I previously installed a Spectre 2517 Regulator but that did not work at all. The variable settings of 2 or 3 psi resulted in 0 psi. Returned it to the parts store.
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Re: Solex Carb

Post by maeserik » Tue Dec 07, 2010 12:05 pm

I have a solex on our M38 and GPW(12 volt,CJ3A engine head), no problems at all, both jeeps drives fine, good acceleration, good cold and warm start.
I use a standard fuelpump and no pessure regulator
On the M38 a M151 solidstate ignition and on the GPW a pertronics, both build in in the distributor, once the timing set OK, no maintenance at all. Not original i know but easy change back to original setup.
sorry for the horn, we are looking for a right one...
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Re: Solex Carb

Post by Bodger Baz » Mon Dec 13, 2010 6:14 am

dave in pa. wrote:Hi all,
If this question has been beat to death...please forgive me.

What are the pros and cons of using the Solex replacement carb? Starting in hot and cold weather? Starting with a hot or cold engine? Acceleration? Idle quality? Power? Torque? How does it compare with other options?

Any user comments or complaints?

Thanks,
Dave
Heres my experiance on the Solex or Carter.
I have a Original Carter carb on my jeep my brother has a French built Solex, both of which do there job very well, both have been relaible, both get a lot of abuse (long highway runs, off roading etc), we did a 700 mile round trip to Tanks In Town in Belgium a couple of years ago both with 3 persons on board and both towing trailers, we were averaging 45-50MPH on the highway and we both used nealry exactly the same amount of fuel, i averaged 17 MPG (english gallons) and my brother avergage 17.5MPG. as of yet i have not found a real noticable difference, cold starts hot starts all no problems, we both have advanced the ignition timing to cope with the 95 octane fuel and both have electronic igntion (best thing i ever fitted to my jeep).

Baz
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Re: Solex Carb

Post by Keep 'em Rolling » Fri Dec 17, 2010 11:23 am

Bodger Baz wrote:..... we both have advanced the ignition timing to cope with the 95 octane fuel and both have electronic igntion (best thing i ever fitted to my jeep).

Baz
Hi Baz,

What electronic ignition did you fit? How much was it? Where did you get it from in the UK?

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Re: Solex Carb

Post by Bodger Baz » Fri Dec 17, 2010 12:19 pm

Its from Jolley engineering, it was £90 i think , i dont use the coils he supplies as i have had some troubles with them, just use a standard coil, 1.6ohm for 6Volt or 3ohm for 12Volt system. its basically a petronix system i belive but all ready to fit for the jeep. i have done thousands of trouble free motoring with these and have not any complaints. one other thing i would say is that he is no the jolliest people to deal with but does supply a very good product that he stands by.

One thing that i did find is that you need to use rubber shielded plug caps, original style caps with arc out to the head when the air is damp due the extra strong sparks. i made my own leads using silicone HT lead and rubber caps either end, not original but very reliable and thats suits me down to the ground.

Baz
International M3L-4 Cargo
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