1972 Moto Guzzi Trotter - I've no idea what I'm doing

[Paul]

With the longer, warmer evenings hopefully on their way I've been looking for a wee project to keep my attention. It couldn't be car-related...my fleet is too big as it is and the crippling increases in tax and insurance, not to mention the rapidly inflating prices of even the roughest of motors, led me to this rather charming FB discovery:





It's a pedal-and-pop 1972 Moto Guzzi 'Trotter' - the name is taken from the Milanese 'Parco Trotter' and not the Del Boy, although the dictionary definition of 'moving at moderate pace with small steps' may well be appropriate.

Here's what I know:

• It doesn't run
• It last ran the best part of a year ago
• It has no V5, being imported some years ago with next to know paperwork although apparently it is 'registered in NOVA'
• it comes fitted with 50cc of throbbing Eye-tal-yan horsepower (just under two powers of horse to be accurate
• Nope, doesn't run
• The fuel tank is listed as holding a capacious quart of your favourite dinosaur juice, possibly mixed with 2 stroke
• With a top speed of 25mph I own a faster push bike
• I have no idea what I'm doing

I think it's got good compression so the plan is to check for a spark at the solitary spark plug, get the carb off and give the jets a good clean, put some fresh fuel in it...the usual stuff. Hopefully that can get her put-put-putting along.

After that I'm not sure - she might not even see a public road if I can't get the paperwork sorted, but that's another problem for another day. Happy to hear any pointers/suggestions as details on these seem to be scarce - I've got an Italian parts manual and that's about it!

[PHUQ]

Magnificent.
With a load of guys from work we did a 220- odd mile run around the Brecons last summer on various sub- 50cc, sub- £400 jalopies (mine being a Mobylette 40v) and I haven't had as much fun in ages.

I assume the oily bits of that were licensed from someone else? Seems a lot of effort for Guzzi to do their own.

[Paul]

Maybe? As the thread title would suggest I'm out of my element on bikes. Can't be that tricky though can it? 😄😄😄

[PHUQ]

Half the fun is figuring it all out. Mine has a £20 Chinese Dellorto knock- off on a new inlet manifold, and a generic Lucas car condenser, and various other oddments.

Dunno what he does for them specifically but I found Malcolm at Classic Moped Spares was very helpful.

[Paul]

Right so I've had a few hours to play with the bike - it's not running yet but here's where I am...

Spark is good and strong. Cleaned up the points and the plug/wire are new.

Fuel tank is filthy and there's a ton of rusty curse word coming through. I've whipped the tank off a couple of times but reckon it'll need a couple more goes.

Compression tested and good.

Had the carb off and cleaned the main jet (which I think was blocked)

I've had it spluttering and backfiring on easy start but no luck feeding petrol directly to the freshly cleaned carb.

My next door neighbour's brother's cat reckons it's down to the internal diaphragm in the carb being brittle and holed and suggested a new carb or a rebuild...pattern ones are easy enough to source (it's based on a dinky dellorto one.

Any other ideas? All thoughts welcome!

[93fxdl]

don't forget this is a 2 stroke, needs oil in the fuel.
Make sure the exhaust and exhaust port are not clogged with carbon and sludge
Ttfn Glenn

[Paul]

So I had another crack at this today...still no luck.

The engine is free and moving, exhaust clear, and I mixed up a fresh batch of premix 2 stroke today as well as clearing the tank yet again (this time with a pressure washer) and cleaning the gaskets and float in the carb. It nearly, nearly kicks into life on easy start but I don't have enough hands to work the clutch, throttle, choke and pedals all at once.

I removed the throttle cable from the lever and checked it was working manually...seems to be. Totally closed unless I yank the cable.

I'm going to run another compression test tomorrow and then I might just bite the bullet and buy a new carb. Don't really know what else it could be.

[93fxdl]

Something 2 strokes can suffer from,is leaking crank seals, gives them a massive intake leak so they suffer a really weak mixture. If possible try a leak down test, with the piston at the bottom of its stroke
Ttfn Glenn
Or try giving it a healty shot of fuel down the carb

[Paul]

Thanks for the heads up. I'll look into

Just checked the compression and it's putting out 120psi - pretty darn good for a 53 year old 2 stroke. So that's another thing ticked off.