Terrot MT1 Motorcycle restoration project

[C3s]

She should be wearing socks when motorcycling

[911hillclimber]

She should be in my garage getting this stupid engine to work.

[smallspeed]

Hahahaha.. I'll come over and watch if you pull that off

[911hillclimber]

Had a small light bulb moment driving to Oulton Park this morning in the old 911 (running perfectly as ever)

All the time I've been trying to start this thing I have only had petrol in the bowl of the carb, about 4 mm above the transfer drilling to the main jet/needle.
I wonder if I rig up a small fuel 'tank' to put fuel into the carb under gravity pressure it will force fuel to be drawn in?
The real tank of course is above the carb with a head of fuel, the flow of which is a crude float with a needle point to the inlet brass union.

?

[C3s]

You're teasing us now

[911hillclimber]

No, not intentionally.
I've been to Oulton Park today, and there tomorrow all day, so will rig something up and try it on Tuesday.
30 mins max should do it.
If this comes to nothing I'll try again, and again etc.
Flip pin' thing.

[911hillclimber]

Well, nothing came of that exciting moment.
Rigged-up a sort of drip feed to the carb bowl chamber and turned it over a 1,000,000 times by hand. Nowt.

The fuel is exactly on the top edge of the vertical main jet tube that has the tapered needle in it (think SU carbs).

When I turn the engine over it spits the fuel OUT!
Checked the plug for sparks, zillions of the buggers, plug still dry as a bone despite all the fuel and Easy Start.
Piston is in the right way round!

Set the timing again but to 5mm piston down BTDC (most recon on 2mm) and checked the points, still at 0.4mm but nothing fires.

I have no idea what else to do now.
The French girl above, Zoe, found her MT1 without a carb and fitted a modern Delorto 21mm dia carb.
I've just ordered (from Hong Kong) a similar carb, dead cheap but it might prove something.
Just joined and posted on a UK Forum for old motorcycles, maybe someone will have a few hints and tips.

[smallspeed]

potentially dangerous idea alert...
but could you remove the carb and spray easy start straight into the inlet? if the engine caught and ran it would only run for a very short period due to the amount of easy start. given the compression ratio could easily be stalled with a hand over the inlet anyway one would imagine?

[Ashley James]

I'd take the plug out and dribble some fuel in

[911hillclimber]

Thanks, but tried ALL of those ideas!
While the barrel of off I shot some petrol/EasyStart into the lower crank case, not a peep.

The odd thing here is even with all these spirits and fumes etc you would expect at least one of ignition moment, a sign something caught and exploded, but absolutely nothing, and a dry plug no matter what!
I've seen Model A Fords, 50 years in a river bed, fire on a squirt of easy start, but not this thing.
Something very fundamental is not right.

I thought the piston was in backwards, the ports would then not align, but it is correct to every picture I've seen.
If the timing was out by a mm or so it should at least fire even if it runs badly.

So, with a light and then heavy dose of Easy straight into the inlet from the aerosol with me furiously turning the engine over produced nothing at all, same with a bit of fuel in the head etc etc etc nothing.

You would think the sparks are not there, but with the plug out and resting on earth it sure does spark and regularly too with each turn of the flywheel.
The head has a brass insert in the alloy head and that is bolted with 4 bolts into the barrel, and the barrel is bolted to the case with 4 x M6 nuts/studs and so to 'ground'

I cannot see the spark not earthing, but there is no whetting of the plug ever with fuel, thus there simply is no fuel getting to the head, and really do not know why not.

The piston is correct (solid skirt, no ports) for the 100cc 2 stroke.
As the piston comes down it compresses the charge in the case, uncovers the port in the barrel and the charge should rush into the chamber, piston up, bang etc, just the 2 stroke cycle.

[SeanP]

Two stroke piston ported engine same as a lambretta?
Isn't the fuel drawn into the crankcase to lubracte the crank and bearings, then up through the barrel ports into the compression chamber. If there is no negative pressure being generated in the crankcase because the main seals are shot/ missing then no fuel will be drawn in even if there is compression being generated in the barrel once the ports have been sealed.

I would try pressurising the the crankcase with the piston halfway up the barrel so the ports are open and check for air leaks around the crank bearings.

Just my two penny's worth. Haven't played with two stroke engines for ages.

Keep going, always enjoy reading about your projects

Sean

[911hillclimber]

Exactly the same as the
Lambretta.
There are no crank seals on this engine! None are shown on the exploded diagrams, and I found non when I took the engine apart.
The Italian engine is sealed, I had a job sealing my last restoration of my TV3 a few years back.
I will try what you suggest tomorrow and report back.

Wish I had some good news to report!

[smallspeed]

Another potentially dumb question - I remember something about kickstarts potentially turning engines over backwards - can't completely understand it but would it be possible to turn the engine over in reverse hence not creating crank case pressure?

[911hillclimber]

Take your point, but when the gearbox is in gear, use the kick start and the output sprocket turns in the correct direction for forward wheel rotation.

Just had a good look through all the pictures I took taking it apart.
There ARE crank seals, felt, and only one is shown on the factory exploded view.

I left these in the cases as they looked too fragile to remove and spared are not available. I can get to both without pulling the engine/box apart so that will be the next port of call hopefully today.

[mrk]

Hope this is your solution...every time I click on this thread I think 'I hope he's got it going!'

Looking forward to seeing it finished