1965 Motobecane D52 5sp 50cc motorcycle

Back in 2015 I managed to pick up a couple of these Motobecane motorcycles. One ran for all of 15 minutes until the case seals disintegrated. The other was seized from sitting; but after freeing up the pistons and reeds, it actually ran (sort of) for a few months. I sold the running bike to someone in LA when I decided I had to have a Dodge Rampage. Later, after a year or two, I decided to buy it back -- at this point it wasn't running anymore.

In the intervening 2-3 years I struggled to figure out how to get it running right. Jesse has one, but has also struggled to get his going reliably. There are one or two others, in the Midwest I think, but I'm not sure if they run either. Finally this summer I managed to figure it out, and to celebrate, and maybe help someone else out with theirs, I thought I'd post about it here.

So, there are two bikes, one from a storage unit in Spokane, WA

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and one from an original member of the Mosquito Fleet

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Both came with a 16 mm Gurtner variation that looks a lot like a Dellorto SHA

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I became so frustrated trying to get these running, that I just started working my way through all the various issues so I could focus on the ignition timing.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

So I pulled off the tanks and treated them before coating them with POR-15 - that stuff is still my all time favorite

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Next step was to swap out the old carbs for something a little easier to work with; one of the carbs had a glass float bowl! I settled on the Mikuni VM18 with an AV/7 style intake. The Mikuni's are a pretty forgiving carburetor.

The D52 ignition runs counter clockwise (just like the SP93 and AV92) so there aren't a lot of extra parts out there. On one of the bikes I was able to get a pretty good spark with the original ignition.

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On the other, I went with a Treats CDI.

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Trying to set the timing on a Treats CDI in the counter clockwise direction is kind of annoying. Fortunately I have a timing light so I was able to locate and mark the trigger point going the other way. I settled on 1.5mm BTDC which is pretty standard for Motobecanes from the 1960s

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Another cool think about these bikes is the rear wheels are mounted with silent blocks, just like old Hondas - makes removing the rear wheel really easy since you don't have to remove the side covers or chains.

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Naz really went through the D52 Bill gave us. He completely rebuilt the transmission and motor - basically every seal was a special order, but he managed to locate them all. He and Garth also replaced the rims and laced the hubs in with new spokes -- the wheels will probably last longer than the bike now :)

Generally it is a blast to ride. 5 speeds seem a little excessive, but it hits 40-45mph easily on the flats.

I really need to take some more detail shots; I think these are probably the most well made Motobecane models I have ever seen.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Also, forgot to mention that the D52s are set up UK style so the shifter is on the right and rear brake is on the left. I need to really work to remember when I'm riding from my DRZ400 often so I don't break when I mean to shift or visa versa.

Here are some more detail shots

the dry clutch

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Plenty of room for the Mikuni

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The tail lamp lenses on both bikes were shattered when we got them, but fortunately there are some pretty good, and in expensive, complete assembly reproductions

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Re: 1965 Motobecane D52 5sp 50cc motorcycle

just a few more photos

the exceedingly elegant but completely lethal levers

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tank badge

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and finally, the accessory foot peg support on the shocks

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Re: 1965 Motobecane D52 5sp 50cc motorcycle

Those are so cool! Great work! I love em. If ya ever wanna get rid of one... That'd be worth a trip over the mountains.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

D52 were commercially imported into the US along with the tt, unfortunately they could not compete with the Asian invasion so they are a rarity in North America...

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Re: 1965 Motobecane D52 5sp 50cc motorcycle

Very nice. I love any older original ( as possible) bike. No matter what the brand. I appreciate your work.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

cool af.

good stuff

Re: 1965 Motobecane D52 5sp 50cc motorcycle

So I actually have two of these but only one came with a motor. I rebuilt the engine completely with lots of pictures, and it's a completely different engine than all the other period motors. The crank bearings and seals are off the shelf so it was pretty easy to do. Not sure about the trans because I haven't taken it apart. I could get mine to run but the ignition is not strong enough to keep it running well. I replaced all the non-D52 specific parts on it, then rewound the ignition coil to factory spec and it's still so low voltage I can't maintain running. I'll try to rewind it with smaller wire and more wraps to get the voltage up and see if it works. It's such a weird bike, I love it but also hate it. It's a mountain I must climb.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Also I'm going to say that while they might have technically been sold here I'd love to see the numbers on how many were. Like 10 ever? I've only ever heard of about 7 in existence to the greater moped riding culture. These had to be one of the rarest bikes ever sold in the US.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Yo I've had a VW Caddy and a BRAT but I lust for a Rampage.

Next time I buy a 4-wheeled vehicle...

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Mmmmm Brat's and Rampage's...oh my! Awesome Motobecane's, I too appreciate your work.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Paul Boyer (OFMC) /

Very cool bikes!!! Great thread.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Engines are basically the 75cc engines with a 50cc piston, cylinder and head, not your usual AV7 running backwards.

It has the Novi 120x 25+3watt magneto, same as the larger cc bikes and Speciales so you need to shop those coils if you need to replace one. If you decide to go CDI then you will need to carefully ream the replacement flywheel for the 17mm crank (and fool around to align the target and trigger for counter rotation). They like 1,5-1,2mm BTDC similar to the AV7 engines.

The crashbox is same as the 75cc and 125cc Motobecane transmissions and similar to a Vespa. External attachments are all truarcs, once inside you will need a variety of pullers because the VAR toolage is very rare for these gearboxes.

> Jesse Stephenson Wrote:

> -------------------------------------------------------

> So I actually have two of these but only one came with a motor. I

> rebuilt the engine completely with lots of pictures, and it's a

> completely different engine than all the other period motors. The crank

> bearings and seals are off the shelf so it was pretty easy to do. Not

> sure about the trans because I haven't taken it apart. I could get mine

> to run but the ignition is not strong enough to keep it running well. I

> replaced all the non-D52 specific parts on it, then rewound the ignition

> coil to factory spec and it's still so low voltage I can't maintain

> running. I'll try to rewind it with smaller wire and more wraps to get

> the voltage up and see if it works. It's such a weird bike, I love it

> but also hate it. It's a mountain I must climb.

Re: 1965 Motobecane D52 5sp 50cc motorcycle

Between July 1964 and July 1969 they only made 6800 Motobecane D52 and Motoconfort C52, only the D52 and D52 Trail (actually called D52tt or C52tt everywhere else in the world) were offered and I believe they were only exported to USA in 1965-66, and not many of them because of low demand thanks to the very affordable Asian bikes flooding the market. The C/D52tt only had 1375 examples produced from May 1965 to April 1969 so it is likely that no "D52Trail" ever madeit into USA.

There was also 147 C/D52e made with factory electronic ignition from 1965 to 1969 as well as 15 C/D52tte, but I doubt any of those were commercially imported, but if they were they would be on the list of the rarest commercially imported bikes..

> Jesse Stephenson Wrote:

> -------------------------------------------------------

> Also I'm going to say that while they might have technically been sold

> here I'd love to see the numbers on how many were. Like 10 ever? I've

> only ever heard of about 7 in existence to the greater moped riding

> culture. These had to be one of the rarest bikes ever sold in the US.

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