Re: Mototrans 250 Scrambler restoration: she's a runner!

[A.I.M]

Hello folks, I have just received (at last) my recovered tinware back from the paint-shop, which has allowed me to install the front forks, headlight support brackets and front wheel to my ’73-ish Mototrans 250 Scrambler today.
However I have noticed that it looks to my untrained eye that I am missing a spacer on the right side of the axle (highlighted in attached photo).

Front wheel right 1.jpg

The left side of the axle has a spacer in place (shown in the second photo).

Front wheel left.jpg

As far as I can measure the forks are parallel, but the wheel is about 4mm closer to the left fork than to the right one.
The axle has a stepped profile, 15mm diameter on the brake-side, 20mm diameter on the speedo-drive side.
I am looking for some help with the following questions:
1. Would I be correct thinking that the washer that I have fitted outboard of the left fork needs to move inboard of the fork to centralise the wheel between the forks?
2. Should there be a spacer on the right side of the axle, between the fork and the speedo-drive plate, to keep the fork in the right position, or is that accomplished by the step in the axle and the fork pinch-bolt? If there should be a spacer, what dimensions should it be?
Grateful for any help you can give,
Al

[Duccout]

Hi Al,

Your wheel is fitted correctly, there is only one spacer and it goes on the left side next to the brake plate, where you have it. Your right-hand fork leg may be pulled out along the spindle, or the rim may be built onto the hub with offset.Try tapping a screwdriver gently into the gap at the bottom of the right-hand leg with the pinch bolt loosened right off, and you should be able to easily push the leg in and out until you find the point where it is completely central. Be careful that you do not draw the legs together as you tighten the axle nut.

Colin

[A.I.M]

Thank you, Colin, I will do just that this afternoon, it's reassuring that I hadn't made any basic errors, nor lost any of the axle components since she was last on the road in 1981 !
Cheers,
Al

[A.I.M]

Your tip worked-out fine, thanks Colin.

I spent a couple of evenings at the kitchen table sorting out the wiring inside the newly-resprayed headlight received earlier this week, then fitted it to the mounting brackets on the forks. I am hoping that I have the wires fed through the correct holes in the bottom of the headlight (Main harness through the rear hole, the wires for the instrument bulbs and the horn/dip switch through the front hole). I will have to connect up all the electrical bits to the harness, and expect to have a few Qs as I progress that, as I am not a competent or confident sparkie (nor mechanic, for that matter).

Now the front wheel is on (with new bearings and brake shoes) I could leave the weight on the front wheel to change the bearings & shoes in the back one. Both mudguards fitted, and the rear number plate support and light. Restored tank and a new seat are ready to fit.

Some tangible progress, at last - but it will be some weeks (or more) before I get the engine back.
Al

Rebuild 2021 01 22 D.jpg

Rebuild 2021 01 22 C.jpg

Petrol tank restored.jpg

[Duccout]

Looking good! Keep us informed.

[A.I.M]

Hi again,
I have almost completed the electrical system, but find I have a handful of questions to resolve before I am satisfied with it:

1. The S-clips that retain the bulb-holder to the reflector seem to be about 4 mm too long and don't keep the bulb-holder tight into the reflector. It is a new reflector from Ducati Vintage Store, but the original Aprilia bulb holder. I don't have the original clips that held the assembly together to compare with. Has anyone else had this problem and resolved it? Is there a spacer missing between the reflector and the bulb holder? I don't want to buy a new bulb holder if that is not the problem.

Reflector back.jpg

2. The little bracket that attaches the headlight rim to the shell has been detached from the rim for a long time, and I can't seem to find any fasteners to keep them together. There are two little round holes in both rim and bracket for some kind of fastener, but I don't know what these are meant to be: Rivets, self-tapping screws, tiny nuts & bolts or something else?

Rim clip.jpg

.
3. The terminals on the coil are marked + and -. Am I correct thinking that the wire from the points goes to the + terminal? Or is it not really relevant?

4. How are the light bulbs in the rev-counter and speedo earthed? It's not obvious to me at the moment, so I'm thinking about trying to run a wire from the cases to the frame - not sure how to attach it though.

Thanks in advance for any guidance,
Al

[double diamond]

598EFC59-B0C7-4AB3-8AA3-DDB649857958.jpeg

Attached (I hope) is a pic of an Aprilia headlight reflector with the bulb holder installed. It looks like your S clips are too long. This would depend on the bulb holder.
The headlight rim attachment bracket is riveted to the rim, typically with aluminum rivets.
The points are the ground for the ignition timing circuit so the point wire should connect to the “-“ terminal on a negative ground system.
Instrument bulbs are grounded through the instrument chassis. The actual ground circuit is probably through the drive cable casing if your instruments are rubber mounted but I don’t recall the specifics of the mount on a Mototrans.

Matt

[A.I.M]

Thank you Matt, that is very helpful. Your bulb holder looks significantly thicker than mine, so it looks like I will have to buy a new one; try to find a rivet kit with small enough rivets, and change the coil wiring. The instruments are rubber-mounted, so the earth connection must be through the drive cables, I can just about get my head around the rev-counter drive cable working as an electrical conductor, but as a non-electrician I struggle to understand how the electric current finds it's way from the front wheel hub back to the frame for the speedometer bulb....
I'm still waiting for my engine overhaul to be completed, just trying to get everything else sorted-out in preparation for it's return.
Cheers,
Al

[A.I.M]

I recently read a few other posts that prompted me to update. Everything except the engine is ready to go:

Front2.jpg

Rear1.jpg

And the mechanic HAS - at last - been working on my engine. It has the plastic oil pump drive gear, so that will be replaced before finalising the rebuild, but everything else seems to be in order. I have ensured he knows all about "lining up the dots" viewtopic.php?f=3&t=3371&hilit=lining+up+the+dots#p26546
He tells me compression is "good" although I don't have any detail.

You might notice from the photos that the front tyre is an original 1970s one, and the rear is probably 1980s with zero mileage, so it would be prudent to replace these. Having done some research I am tempted to try Continental TKC 70s - does anyone have experience, good or bad, with these?

I hope to have it ready to start the administrative procedures for getting on the road before mid-winter, but that could be another very time-consuming process as I have to deal with vehicle authorities in two countries (UK first, then France).
Regards,
Al

[Duccout]

Hi All,

I think any modern tyre will be good. Don't hold your breath if dealing with the DVLA, I read last week that they have a backlog of 1.4 million cases, AND the union is calling for them to strike........

Good luck,

Colin