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Help me identify this 250 single

Posted: Sun Aug 20, 2017 3:53 pm
by HMBAtrail
Hello to all! I just joined. I have a 1974 450 and recently picked up a 1972 250. It is the 250 I'm trying to figure info on. The bike was fairly clap-trap when I bought it and it will make a wonderful Winter project.

So I'm fairly certain the frame is a Mototrans (Akront rims, Motoplat ignition, Telesco 35mm fork with single leading shoe brake on the left and a faux scoop on the right, snail cam chain adjuster) plus the cover for the steering lock has "Barcelona" stamped into it. It also has the ignition key location mounted under the tank at the rear on the left hand side of the frame. The serial number for the frame is stamped into the head tube on the right hand side toward the rear. Number is 11043*

The motor is stamped DM250 on the left hand crank case. On the right hand side is 11446*. Tach side bevel cover has "Made in Italy" cast into it although there is no tach drive on the cover. Timing cover also has the "Made in Italy" below the Ducati casting. The clutch adjustment cover just says Ducati.

I haven't yet pulled the cover to see if I have a steel or plastic oil pump gear.

So while I'm fairly certain the frame is Spanish, is the motor?

Thanks so much in advance!
Tim O'Donnell- Indianapolis, IN

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Re: Help me identify this 250 single

Posted: Mon Aug 21, 2017 6:06 am
by Ventodue
Hi Tim and welcome to the Forum.

Jon Pegler's really the man for this, but ...

To my eyes, that looks like a Mototrans head. See the attached.

Bologna vs Mototrans heads.jpg


Craig

Re: Help me identify this 250 single

Posted: Mon Aug 21, 2017 9:40 am
by Jon Pegler
Hi Tim,

Your motor is certainly a Spanish 250.
Don't be fooled by 'Made in Italy' on the timing cover.
All the widecase numbers that start 114---, 115---, and 116 are Spanish built.
Are you sure your frame number is 11043 or is it 41043?

With the ignition switch on the LHS near the back of the tank it sounds like you've got a widecase 250 Road.

Jon

Re: Help me identify this 250 single

Posted: Mon Aug 21, 2017 1:17 pm
by HMBAtrail
Thanks Jon! Quite certain on the frame ID. See attached pic. I also included a pic of the 250 with a very ugly tank and seat as well as my 74 for good measure.

So are the internals of the Spanish similar enough (I.e. If I need a re-bore do I need to hunt down Mototrans specific pistons? What about valves and springs?)

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Re: Help me identify this 250 single

Posted: Mon Aug 21, 2017 3:06 pm
by Jon Pegler
Hi Tim,

The photos of the 250 and it's frame number make things a little clearer.
The frame number 110436 is in the Spanish scrambler number series, not the 250 Road. I was slightly confused as you had left off the last digit in your previous post.
Mototrans built scramblers both for sale by themselves and for sale by the Italians.
The Spanish built scramblers sold by Bologna all had frame numbers starting DM 250S ------
The scramblers sold directly by Mototrans all seem to start 110--- , as yours does
There were not many produced, although I do not know the total number.
Engine internals are almost identical with the Italian motors, so fully interchangeable.
You could well have the plastic oil pump drive gear fitted inside.

Jon

Re: Help me identify this 250 single

Posted: Mon Aug 21, 2017 3:20 pm
by HMBAtrail
Agree on the oil pump. I haven't yet had a chance to see for sure although if I was a betting man . . .

Re: Help me identify this 250 single

Posted: Tue Aug 22, 2017 7:34 am
by Ventodue
Jon Pegler wrote: Mototrans built scramblers both for sale by themselves and for sale by the Italians.
The Spanish built scramblers sold by Bologna all had frame numbers starting DM 250S ------

Hi Jon,

As far as the engine numbers are concerned, did the Barcelona-built Scramblers always use the DM engine prefix, rather than MD?

Cheers

Craig

Re: Help me identify this 250 single

Posted: Tue Aug 22, 2017 8:19 am
by Jon Pegler
Hi Craig,

All the widecase motors built by Mototrans are numbered in the same way as their Italian cousins, namely, with DM 250/350 on the LH crankcase half.
The frames were still usually stamped MD----- followed by a 5-digit number.
It's interesting that the photo of Tim's frame number does not have the MD stamping.
That's quite unusual.

Jon

Re: Help me identify this 250 single

Posted: Wed Aug 23, 2017 2:52 pm
by Ventodue
Thanks John.