Terrot MT 1, 100cc 2 stroke: non-starter!

[iansoady]

Very tidy, well done.

[Terrotmt1]

Thank you.
Run a wire to Earth the points?
There is not a wire like that on the diagram of this bike, the ignitions seems to be independent of everything else, I've the lights.
There is nothing else on this bike, not even a stop light.
All I have is the external connection that the light circuit is connected to.
I think a kill button was mounted on the handle bars, but this part was missing off the bike when I had it.
Can you detail things a bit for me please?

[Rex]

Certainly. I'm not saying your bike had this set-up originally, but can you run a wire from the insulated side of the points to a handlebar-mounted kill-switch, such that when the button is pressed the points are earthed?
Note, don't use an old-style metallic push button or you'll get a tingle when you push it.  

[chaterlea25]

Hi,
Did the original carb have a tickover adjuster?
Usually they did not and the engine died if the throttle was shut off
If tickover is set on some old 2 strokes it can cause "surging"  as you shut the throttle when riding the bike

John

[Terrotmt1]

OK...
I cannot see anything to short the ignition out, though I will search again for the mag diagram.
It seems the wires from the lighting side go to a switch so if there is an off position on the lights, can that kill the ign somehow. I'm not sure how to do this (engine kill)

The tick over setting on the original carb is by a threaded sleeve on the top of the carb where the cable passes into the carb and to the piston.

[chaterlea25]

Hi,
To add the ignition cutout, You need to add in an extra wire
Connect it to the junction where the coil/condenser are joined to the points, this is usually a little stud and nut
Run the wire to where ever you want to fit the cut out button or switch, the button body or other side of the switch
must be earthed/grounded to the frame/engine

Ok on the carb, just like all the old smokies, revs up when the handlebar is turned right and engine dies when turned left
 

John

[Terrotmt1]

Ha!
Thankyoufor the info, will see what I can rig up.
Older engines I've seen have a spring steel blade that the rider presses against the plug top and to earth to kill the ignition, but this is not shown on the factory engine diagrams.

[33d6]

CL25 was right first time. Back in their day riders would have the throttle set so the engine stopped when it is completely closed. It was meant to be like that. Not only was it how you stopped the engine it also stopped four stroking and 'surging' on the over run. They also used a throttle twistgrip fitted with a friction adjustment that they kept tight enough so the throttle didn't close when you took your hand off it. You both twisted it open and closed.  As the bike has no indicators you had to give clear hand signals instead. Having a twistgrip that slams shut when you remove your hand to signal doesn't earn you many brownie points from following drivers as they take avoiding action. If you wanted the engine to idle at red lights and stop signs you just didn't entirely shut it right off.

This original style set up suited the riding style of the day. Modern bikes have had standardised controls for so long we tend to forget these old bikes pre date all that and can be utterly different in their approach. There is no right way or wrong way. They just did things differently back then and it works just as well if you do it their way. In fact it can be quite entertaining setting it up as per factory and then drive your mates nuts letting them try to operate it.
Cheers,

[Terrotmt1]

This is my first 'early' bike, my previous ones were a 75 Honda CB 175 and a 63 TV3 Lambretta, all had self closing throttles.

I have spent ages (and failed) to get this bike's throttle to self close, it always would stop 'early' and now I know why!
This makes all the sense in the world now, thank you all very much.
Hope to get the bike running properly off the tank and get it back on the ground this week and move towards selling it.

My next one is a humble Peugeot BIMA, 1952 and that has a pair of throttle cables, so must work in the same manner.

Great!

[Rex]

Another old Froggie?
You must be a glutton for punishment!

[Terrotmt1]

Lambretta and Honda were all DIY but you just spend yourself through the restoration via specialist sites.
These old French bikes are much harder!

BIMA:

[mini-me]

one "throttle" cable probaly works  a decompessor as they do on mobylettes

[Terrotmt1]

Think you are right.
I bought this BIMA from France but found the Terrot just down the road from me a month later so have not distracted myself with it until the Terrot is done and gone, just got it DVLA'd.

[Terrotmt1]

This Terrot is driving me insane!

With the Chinese carb on it might start, and when it does it revs away like mad, will not 'throttle' at all.
If I put the new exhaust system on (absolutely straight through) it won't start.

When it did run today, the lights worked, so at least some good news.

Tried the original again, and nothing. It has never started with the original carb on. The carb is cleaner than when AMAC made it, fuel level is 'just' on the top of the main jet tube where it exposes in the bore of the carb, needle is on 2nd of 3 groves and the jet (there is only one) is '55' as per MT1 spec for the 903/165 carb.

Just what am I doing wrong!

The sparks are huge, blue and big, I could weld with them.
Timing must be right (5mm piston down BTDC) as it runs on the big Chinese carb.

HELP!

[murdo]

I think you may have an air leak somewhere in the intake.