You are here: Home > Other makes > Other vintage scooters > Liquid cooled Maicoletta

Liquid cooled Maicoletta

Late in 2000, we were approached by Graham Fisher (the well known Moto Rumi collector and racer of strange scooters), who wanted us to make him a barrel kit.
It was for his Maicoletta sidecar outfit, which he uses for racing.
In case you are not sure, Maicolettas are the 50's German scooters with big chunky front ends - like Flash Gordon might use for nipping to the shops!

The standard barrel was not suitable for tuning, but Graham had found a barrel from a military model Maico off road motorcycle that looked like it had plenty of scope for tuning.

We are lucky that we managed to get some "before" pictures of the barrel, because no-one would believe that the end product, a 40bhp reed valve liquid cooled barrel, could possibly have started life on a 50's army bike!
The pictures may also come in useful when Graham races the scooter, as the scrutineers may have trouble believing that it is a Maico barrel he is using.

The barrel kit was not cheap, but it was an interesting winter project for the team at MB Developments. It shows that we can turn our engineering skills to any project, not just Lambrettas!

A view of the barrel before we started working on it. There has been a bit of pre-tuning on the barrel transfers so that we could tune the casings.

You can appreciate the size of the original barrel now. It was a big cube, each side was about a foot long. It was very heavy with all those fins. The barrel was reduced in size on a lathe and then tidied up on the miller. Then a piece of sheet metal was bent and welded on to make it liquid cooled.
Sounds easy, took 3 whole days!

A shot of the "spare" engine which was used as a jig to set the port timings before the barrel was tuned.

Side view with the timing disc on, measuring all the port timings for our records.

Maico cylinders are always piston ported. This cylinder was modified to use a 6 petal reed valve. With the one off carb mount it looks like it is meant to be there.

Exhaust port with bridge, showing the one off steel exhaust stub

A view down inside the cylinder, showing the transfers, boost port and the bridged exhaust port. As you can see it is an iron linered sleeve fitted to the alloy cylinder.

Another view, showing the barrel with the head fitted. This was just before we measured the compression.

View of the liquid cooled head showing the combustion chamber, water jacket and the o ring sealing grooves.

It is hard to believe that this 2 piece head started life as 2 big chunks of alloy bar!

2 part liquid cooled head. Looks like the ones we make for Vespas and Lambrettas, shows we stick to the long proven design for other jobs.

View of the inside of the liquid cooled cylinder head

Please E-mail us with any questions or comments.

	A view of the barrel before we started working on it. There has been a bit of pre-tuning on the barrel transfers so that we could tune the casings.
	You can appreciate the size of the original barrel now. It was a big cube, each side was about a foot long. It was very heavy with all those fins. The barrel was reduced in size on a lathe and then tidied up on the miller. Then a piece of sheet metal was bent and welded on to make it liquid cooled. Sounds easy, took 3 whole days!
	A shot of the "spare" engine which was used as a jig to set the port timings before the barrel was tuned.
	Side view with the timing disc on, measuring all the port timings for our records.
	Maico cylinders are always piston ported. This cylinder was modified to use a 6 petal reed valve. With the one off carb mount it looks like it is meant to be there.
	Exhaust port with bridge, showing the one off steel exhaust stub
	A view down inside the cylinder, showing the transfers, boost port and the bridged exhaust port. As you can see it is an iron linered sleeve fitted to the alloy cylinder.
	Another view, showing the barrel with the head fitted. This was just before we measured the compression.
	View of the liquid cooled head showing the combustion chamber, water jacket and the o ring sealing grooves.
	It is hard to believe that this 2 piece head started life as 2 big chunks of alloy bar!
	2 part liquid cooled head. Looks like the ones we make for Vespas and Lambrettas, shows we stick to the long proven design for other jobs.
	View of the inside of the liquid cooled cylinder head