mototrans 250 deluxe model

[syrup head]

Hi everyone
I am rebuilding a mototrans 250 deluxe and need the following info sprocket sizes valve/ignition timing and tappet clearances for starters.
If anyone knows where i can get a workshop manual in english or any info on this model i would glad to hear from you.
cheers syrup head

[Jon Pegler]

I don't think that you will find either a manual or parts book in English for a 250 De Luxe.
The only Spanish Ducati I can think of that had an English handbook was the 250 or 350 Road model, all the other manuals and parts books are in Spanish.
What year is your De Luxe?
Is it a 4-speed or a 5-speed model?
Engine or frame number will help determine which you have.
Most De Luxe 250s use the following settings:-
Points gap 15thou
Plug gap 20thou
Valve clearance inlet 5thou
exhaust 7thou
Timing static 10degrees
full advance 36 degrees
Front sprocket 17 tooth (early) 15 (late)
Rear sprocket 42 tooth (early) 47 (late)

Generally fairly similar to their Italian counterparts.

Jon

[syrup head]

Hi Jon
The bike has not been date registered but i believe it is an early 4speed model. The frame number is MD88294 and the engine number MD88482 .
i am trying to gather info on this model so this site seems my best bet.Thanks for the info much appreciated.
Cheers syrup head

[Jon Pegler]

Your frame and engine numbers would probably indicate that it is a 1965 model.
If you have the original forks fitted, they will have a date stamped on them like the Italian models, on the lug that engages with the brake plate, on the right hand side.
That engine number should be a 4-speed model.
5-speeds didn't come in until 1967.

Jon

[syrup head]

Hi Jon
I checked the forks but there is no date on them. I think you are correct it probably is from the mid sixties the styling would seem to support that. I am thinking of changeing to 12volt electrics any idea which one to choose.
Cheers syrup head

[JimF]

I don't know Mototrans bikes but converting to 12-volts can be challenging. There are many threads in this forum about doing it with your existing alternator at one end of the spectrum and then at the other end of the spectrum there are aftermarket alternators that might get you a few extra watts of power for the change-over but they are expensive.


You'll have to remember that if you upgrade you have to change all your light bulbs, your horn, your regulator, your battery and possibly (probably) your ignition coil too.


Power is power, regardless of whether or not it comes in 6-volt or 12-volt flavor. What I am saying is that 50 watts in a 12-volt system is the same as 50 watts in a 6-volt system. There is absolutely no difference.


Some reasons to change are perhaps 6-volt consumables like light bulbs might only get harder and harder to find. In a 6-volt system the current (amperage) is doubled over that demanded by a equal 12-volt system requiring larger gauge wires, but wire is relatively cheap.


Six volt systems suffer more easily from power loss in poor (resistive) interconnections, but we should not have any poor connections anyway.


Jim

[Jon Pegler]

Another possible way to date a 250 De Luxe is to see if there is a date stamped on the body of the speedometer.
If you have the original VDO Avis speedo, it will have a month and year dated on the bottom of the speedo body.
I wired my 250 De luxe up 12 volt fairly cheaply.
The Motoplat alternators are not wired up like the Italian Ducati ones and are simple to convert to 12 volt.
Where are you based in the world?

Jon

[StewartD]

Syruphead, Jim,

I converted my 450 Desmo to 12 volts and the 6 volt horn was left as it was. It really screamed but it lasted for the 10 years I rode that bike. I didn't use the horn that much though. I am doing the same on my Mach 1 that I have only just got back on the road. Will the life of the horn be shortened? Also I'm wondering if a relay for the horn button would be desirable.

On the issue of power from a 6 volt versus 12 volt conversion, I thought that current induced in a coil by a permanent magnet is determined by the strength of magnetic field and the number of coils of wire. I couldn't find anything on the net to confirm this. It is something I remember from long ago in Technical College.

Wikipedia has the following on voltage produced by a permanent magnet alternator:

"....Since the permanent magnet field is constant, the terminal voltage varies directly with the speed of the generator."

The standard Ducati regulator limits the voltage to 6 volts and a conversion such as mine, will limit the voltage to 12 volts, by using a zener diode.

So if current is the same and if the system voltage is changed from 6 volt to 12 volts, the power output is doubled. My experience with the 450 seemed to confirm this. I used higher wattage globes and never had problems with batteries going flat. The 450 was my only transport for much of the 10 years I had it, and it did lots of work at night.

This sounds too good to be true; am I missing something here?

Cheers,

Stewart

[syrup head]

Hi Jon
I do have the original speedo and i was chuffed to find that the date on it is october 63 and the speedo reading is 35837.I guess that is kph as the dial goes round to 160. I,m at the moment looking at all the options regarding the electrics but your conversion seems interesting.
By the way i live in sunny London.
cheers syrup head

[Jon Pegler]

Hi Syrup head,

I don't think your speedo is the original.
My own 250 De Luxe is definately a 1964 model, but has a lower frame number than yours.
I have sent you a PM if you would like discuss why I think your machine is probably an early 1965 model.

Jon