Terrot MT1 Motorcycle restoration project

[911hillclimber]

I won't be riding it!
I want to get it right and sell it. There is another one in the shed for this winter unless I paint the 911.
It is a shame the engine worked well with the big carb when it eventually started, and now it starts the throttle response is poor.

[Kneeslider]

Yay. Progress! Stick at it, and you will surely get there.

[Ashley James]

I won't be riding it!
I want to get it right and sell it. There is another one in the shed for this winter unless I paint the 911.
It is a shame the engine worked well with the big carb when it eventually started, and now it starts the throttle response is poor.

It won’t have a good throttle response if the carb is too big. If the one you’re using is larger than the original, that might be the cause.

[911hillclimber]

Agree.
It won't start on the original at all, never has for me.
I have another to try.

[911hillclimber]

Well, the 'middle' size carb from China (up to 80cc) does nothing.
Back to the 'Big' size carb (up to 125cc) now does nothing.

Not a fart or a pop.

It started 3 times in succession yesterday.

[jjeffries]

A couple of weeks back I was wondering how this project was going. I admit that at this point I'd be hurling it off the cliff near Brighton, Quadrophenia-style, although maybe as a non-runner it would need such a hard shove that I'd plunge off the ledge with it. What a monstrous little machine to respond so ungratefully for all the time, effort and money you've lavished on it! Maybe you could sell it as-is to a French bistro to use as window-dressing? I'm only half-kidding; I had lunch last week at a British Brewing Company (geddit?) near Boston...the chain which owns it has maybe six of these "pubs", all Brit-themed, so along with the obligatory posters of Winston Churchill, each has a Royal Enfield on display. I looked and they are Indian-made examples, but when you're eating the American interpretation of Bubble & Squeak, who really cares? In the meantime, I remain in awe of your sticktoitness. Best, John.

[911hillclimber]

When does tenacity become stubbiness become stupid?

Maybe they all apply to me and this French follie John?

Will leave it alone to sulk for a while.

[Ashley James]

Well, the 'middle' size carb from China (up to 80cc) does nothing.
Back to the 'Big' size carb (up to 125cc) now does nothing.

Not a fart or a pop.

It started 3 times in succession yesterday.

Modern 125s do about 8,500rpm and the Terrot 5,000 max so you’ll be better off with a smaller carb.

[911hillclimber]

The original is tiny, the small Chinese carb almost the same, but this engine has never even fired once with either.
The only time it has run is with the bigger carb, a Dellorto rip-off.
This carb is the one used for several bikes of this era and several in France are using it on MT 1 Terrot like mine. Its design is very modern and beautifully made.

It is odd that when the secondary compression was poor but the engine actually ran the throttle response was great, total response to the twist grip movement.
Yesterday is was poor, delayed, uneven revs at steady throttle, not good at all, but it did re-start twice.

Thus, near zero starting before, after the rebore etc starts (yesterday) but runs bad!

There is a definite 'knack' to getting it started.

[jjeffries]

Any chance (or desire) of finding a used, running engine in France? John

[jjeffries]

Any chance (or desire) of finding a used, running engine in France? John

[911hillclimber]

No desire tbh, this engine is all re bored, re sealed and as good inside as it gets.
In Germany now on hols, well away from the French Follie....

I will hit it hard in thenext few weeks as my determination has gone to stupid obsternance.

Nothing like this has ever beaten me in 50 years of tinkering, so not ready to admit failure.

I have never managed to find an engine on eBay France, sometimes parts, but nothing like a completed engine.
I have primary and secondary compression, fresh ignition parts, but the carb is No 1 suspect.
I have a period Villiers carb to try next time. The advantage of this carb is I can get different jets for it easy from local Villiers Services.

I'll have this thing yet.

[911hillclimber]

Well, 'we' have been sulking for a year now, my French Folly and I and summer is almost here, but also the rest in the hill climb season for about 5 weeks, so time to think this problem through.

I will give this engine one more round of effort. The kick starting twisted my ankle and knee which are both still dicky, so I have bought a 240 drill that runs both directions. This means I can spin the engine using the drill on the crankshaft directly and continuously.

If that does not start this bitch, it is time for a radical change of direction, and I've just been inspired by a bike on ebay!

A small company in India have made an electric motor conversion for a single cylinder motorcycle where the barrel/piston and head are removed and the motor drives the crank so retaining the lower half of the engine, clutch, gearbox etc, see pictures below.

I really fancy this as a project as this bike is only worth £1500 or so, but to electrify it and have the batteries and so on in the pannier box retaining all the classic parts could be a nice conclusion and something to exercise the grey matter a bit.

Anyone come across this kind of conversion at all?

I've emailed India to see what is available.

[911hillclimber]

The spark of an idea to go 48V was soon earthed when you get to build the costs up.
The Indian and other companies offering these conversions are hopeless and a DIY build up of parts came to around £500 so just too much.

Plan B however has been more fruitful but maybe more risky.

I found a very ready source of pedal bike engine conversion kits esp in the USA where this game is huge.
I ended up with a 50cc 4 stroke kit for £150 delivered from Germany .
The engine is small enough in general size to fit the Terrot frame, simple mounting and has a lot of good parts with it, twist grip (it is a twist and go transmission), kill switch etc.

I'm about 1/2 way in so far, glitch free until the mating of front sprocket to original 1950 rear sprocket reared it's head which I think I have a solution for.
Anyhow, for those interested, here were are so far:

Engine out again and down the shed all wrapped up.
The integrity of the bike's frame has to be restored, the engine was stressed, so the new engine mount must be strong.



The kit came with a flat mounting plate that was perfect fit and alignment! I made up various extensions in 3mm steed and turned bosses to pick up the original mounting points and still
managed to get good chain alignment. I'm hoping to re-use the original chain guard, bit there is one in the kit to use too.



The engine could then be put in place temporarily until all is sorted.



Old clutch cable came out as no longer needed, and so to the throttle cable and original twist grip. The parts supplied with the kit needed surprisingly little tweeking to fit and has the engine kill switch integrated, so neat.
The throttle cable outer is too long so the inner will not allow enough throttle opening, but that is a minor issue to fix.

The biggie is the incompatibility of the engine chain sprocket size to suit the original rear sprocket and 1/2" chain size.

I think I have found a solution, awaiting an email from a classic bike specialist.

While I was there I also converted the left foot operated rear brake lever to toe operation instead of the very awkward heel operation.

[911hillclimber]

Lots happened to get the engine in which it now is.

Sorted the exhaust down pipe eventually, not neat but will do for now. Hidden the pipe under some wrap and still itching...
Other issue was the sprocket to match the 1950's spec chain. Never knew chains were so complicated, but with the help of 2 girls in 2 sprocket companies and some home machining all is well and together.
Chain needed a link taken out to fit.

Slackened the rear wheel axle nuts to pull the chain tight and one of the nuts stripped..
It is of course weird and special, just like the rest of this French Folly, but might have found some nice new ones in Sweden.

This will stop me actually riding the bike this weekend!
Adding fuel tomorrow to get the engine going.

Next will be the battery to feed the lights and it will be ready to sell/enjoy/throw away.