Fixing A VERY OLD Solex

I was riding my bike down the road today, when I was looking at some trash an old lady was throwing away, I saw this VERY OLD solex moped. I am aware it needs a carburetor (sp?), but odds are it needs some other things also. Any input as to what it would need would be extremely helpful, and any ideas of where to find some of the items needed. Thanks.


Re: Fixing A VERY OLD Solex

Oh, and I can take more pictures if that would be helpful.

Re: Fixing A VERY OLD Solex

here are some close up pics of the engine.


Re: Fixing A VERY OLD Solex

one more


Re: Fixing A VERY OLD Solex

It's actually not all that old. Looks like a basic 1973-75 3800.. I'm currently working on getting one together. Briansolex has a lot of knowledge on these bikes, and has helped me out a lot.

What's wrong with the carburteor? They're very simple carbs..

Re: Fixing A VERY OLD Solex

Hi Dan,

Legendre is correct, it looks like an early 70s model S 3800. If you would like to know the exact year, let me know the seven digit serial number _stamped_ into the top rear of the motor. It will probably start with a five. Don't be thrown off by the 14-3-1966 date cast into the top of the motor, it is the date of approval of that type motor. The seven digit frame serial number stamped into the right side of the frame downtube near the neck weld would be helpful, but not necessary.

To try to get your bike started, you will need at least the fuel pump, fuel pump diaphragm (sometimes incorrectly called a membrane), and the fuel pump seat. That's what is missing from the front of the motor.

Go to: You need ref. 15, 16 and 17. A problem will be that I only see two of the four screws that hold the pump to the crankcase. These screws are M4 x .75, not easily obtained. Perhaps one of the forum readers can help you out with two screws. They are available from France. You might be able to retap the holes M4 x .70 and use the screws from Velocruz, but I have never done that.

You are also missing the flywheel hood, and motor hood which houses the headlight. The flywheel hood is available from Velocruz, no problem. The motor hood is also available there. The headlight that they sell will fit, but you will need an adapter to install a smaller bulb, because your electrics will probably not power that bulb the way they are.

The taillight is not original and looks like an Aprilia unit. These units were added by some dealers or distributors usually to make the bikes a little more legal. Yours may have a crude brake light system added to it, also, that only works when the rear brake is applied; can't quite tell from the photo.

There were probably Solex stickers on the sides of the frame downtube originally.

Attached is a photo of basically the same bike.

I'd be happy to try to help you any way I can.



What's with the Solexine can?


I keep seeing Solex bikes with that green & yellow Solexine can attached to the front fork (as in your photo). What's the history behind that?

Re: What's with the Solexine can?

Hi legendre,

BP used to make a pre-mixed fuel especially formulated for the Solex, but usable on any two-stoke. It was nothing special, just gasoline and oil. It was sold through a pump in a few bigger stations, but usually in metal cans like you see in the attached photo of my 3800 at the Bastille Day Rendezvous. There were two types/sizes of cans. A smaller one which was mostly yellow (very rare to find now) for the earlier Solexes and then the green and yellow can like I have, which is two liters. Two liters of fuel in a Solex is 100 miles, so with the original tank full you'll go 50 miles and then with the extra 100 miles in the Solexine can, you've got a range of 150 miles without stopping for gas. There were several different carriers made, some attach to the front forks like mine and some attach to the rear struts. Of course the Solexine is long gone from my can, so I just fill it with pre-mix before any long rides and I'm set.

Some ads for Solexine can be seen at:

The carriers for both the older and newer style Solexine cans and the newer style cans themselves (used) are available from <>



Re: What's with the Solexine can?

Bumping this very old thread because it’s a good overview of the Solexine can and comes up on Google when you search for that.

I just visited the Musée des Arts et Métiers in Paris, which has a well preserved 1948 Solex that includes the yellow Solexine can.


Re: Fixing A VERY OLD Solex


Re: Fixing A VERY OLD Solex

I never had a setup like that, but I did build a bracket that attached to the left rear, beside the wheel, that held a one gallon plastic oil jug, which I carried premix in. I had to drill a couple of holes in the left fender strut to install it. Then I installed nylon bicycle panniers on the rack, one on each side (basically saddlebags) and carried extra fuel in those. I removed the bracket, and replaced the fender strut that I drilled holes in.

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