Terrot MT1 Motorcycle restoration project

[911hillclimber]

Thanks!
On the Sprocket web site they list an engineer type who can turn old and new to fit and weld the two together.
I had thought the hardening was case, but I think it is through out the piece.
I had thought of wire eroding the two diameters and welding.
Need to ask a few questions first.

[911hillclimber]

After a long holiday in Italy and some racing after, I finally found some enthusiasm for the Terrot.
This project is now taking too long and I'm loosing my mojo for it I must admit, especially after the last hour..

Put petrol in the float bowl, checked for a spark across the 16 thou plug gap and turned the engine over many times on the kick start. Nothing.

Removed the carb, poked out all the jet holes and body passages (just one!), re-assembled and tried again. nothing.
Found TDC and rotated the crank back until the piston dropped 5mm (Terrot's spec) and eventually got the flywheel off and repositioned it to the markers.
Nipped it tight and tried again. Nothing.

At this point I have walked away.
It would make a good push bike because I recon that's all you can do with it!

I'm sure I have a good primary compression, I have secondary compression, I have fuel and I have a spark.
I have no combustion.

Maybe tomorrow will be better than this low point.

[911hillclimber]

Well, the engine will not spark.
Did a few weeks ago, will not now.
Tested the condenser, and that charges (using the multi meter) and after a few seconds shows 0.5volts that slowly decays to near zero volts after 30 seconds.
Tried another spark plug, no spark.
The lead to the plug from the magneto contact is good, points are 0.3mm gap. All the leads from the points to the condenser are good.

Any ideas what else it could be?

[Ashley James]

They often need remagnetising?

[Kneeslider]

Hmm, It worked before, so I wonder what has changed? Presumably the coil (s) check out, and aren't grounding on anything? What was the spark like when you had one? I once had a Puch 50cc moped with a total loss electrical system that might have been similar to this. It sparked, but the spark was so weak that in the combustion chamber, the pressure generated by the piston would be enough to stop the spark. This was because the flywheel magnets had become de magnetized, but not completely. The bike belonged to a friend who had attempted to re time the spark, and the flywheel containing the magnets needed to be removed from the taper, so he had wound up a puller, and when that didn't get the flywheel off, he had hit it till it came loose. In the process that had lost some of the magnetism! That took some figuring out!

Also, bear in mind that once mixed with 2 stroke oil, the 2 stroke mixture 'goes off' in a very short period. I have no idea why, but I found that a 65hp Rotax twin microlight engine could only go a couple of months tops before it won't start. Change the fuel for fresh, and it went every time.

[911hillclimber]

I copied my question on the French Terrot.org site and a French man suggests a rebuild of the ignition core in the magneto.
The part is tricky to get off but I think it is the next stage.
The few sparks were fat and blue but now all is dead.
The flywheel has been pulled off several times now setting timing etc but no real shocks.
Could just simply need sending to a bike specialist for magnetos and start from there.

New wires and a re-magnetisation and things will be like new as Ashley suggests..

[Ashley James]

Look up how to make a remagnetising coil because it's quite simple and you can try that before having it rewound.

There's a chap with a couple of Berliets down the road here, called John Tanner and known as Fatspark. He'll rewind it for you if necessary. Or I think he still does it. I'll ask him if you're stuck.

[911hillclimber]

Thanks Ashley.
There are a surprising number who do these things, one in Hereford, so a nice day out!

First I'm going to try something new to me....
simple things first!

I've checked the 67 year old capacitor that charges and discharges so ok, but for £8 I think I can get a new Villiers 6v to replace it. See if that gets a spark.
Then I will change the 67 year old plug lead....see if THAT get a spark.

Finally check the primary/secondary windings for continuity. The magnet sure attracts strongly a steel M8 nut...

If all this fails then a rewind but getting the static coil off the engine looks tricky as I think it is riveted on!
The static assembly is not on a separate plate but assembled directly onto the crank case.

This must be easy to resolve.

[911hillclimber]

Having spent many days with a '68 VW Camper Van, I had a bit of time today for the bike.

Bought a new capacitor (Villiers) as a substitute for the 67 year of original, a new plug lead but first a continuity check (again).
Found a good diagram to follow off the internet and found the secondary winding to the plug lead is open circuit.
Every other wire bells through a treat.

Found 2 screws on the assembly and after removing them and with some gentle persuasion the whole magneto came off the engine block.

Task now is to send it away for a re-furb and I think we shall be in business starting the bike.

[Ashley James]

Well done! Glad you sussed it.

[911hillclimber]

Hope this will crack it and I can finish the bike.
Waiting for a response from a specialist in Shropshire who seems to be of the right order.

[smallspeed]

excellent news! will keep my fingers crossed this sorts it - looking forward to the obligatory first start-up video

[911hillclimber]

Well.....
The specialist in all magnetos does not do flywheel magnetos!
Bit more Google needed.

This bike puts up a fight!

[Ashley James]

Give John Tanner a ring, he's a Veteran car man just down the road from here and he'll take on most jobs. He has a couple of old Berliets you might like to see.

https://brimscombe.cylex-uk.co.uk/compa ... 59779.html

John on the right in a 1904 Berliet

[911hillclimber]

Thank you, I'll give him a ring on Monday.