Cowboy cylinder porting

[johnny650]

It is possible to get a machine shop to take the gasket face at the base as far up the cylinder as the fin (£30?), using the fin as the gasket face and a packer to match material removed+ 0.25 bringing squish sweet to give you the gasket area to make long term safe.
. it would look like previous "tuner" 'ported' only the base of the cylinder. There's a heck of a lot of potential in those cylinders.

Machining the cylinder back to the first fin to increase gasket area is a great idea, (I'll get a quote from a local Engineering shop ) , as is matching manifolds to ports and some port enlarging I imagine this is all basic stuff to tuners.

I only purchased this cylinder kit as a stop-gap measure whilst I rebuild the original engine & gearbox so I would have something to ride and give me more rebuild time. I had intended to shove this on the shelf as an emergency spare once the original engine and box is rebuilt . However once I have done that I might try experimenting a bit with the 185 .

This is the current port map for the 185 .. I'll see if there is any specific porting advice in Webster etc
Lambretta 185cc Port Map by John, on Flickr

[johnny650]

I noticed on your other tread that you only have the mixture screw out 1 turn, try 2 full turns and see if that is all thats needed.

thanks for the suggestion I have tried to vary the setting but its pretty fruitless when I couldn't get it to run .
It does now run but still very rich and its spitting back a lot through the carb. I probably didn't notice this when I tried it with the hose in place previously. When I can get it to run to warm it up I'll adjust the mixture screw which will tell me if I need to go down on the pilot jet.

It ran quite well yesterday until the throttle cable nipple came loose and left me stranded on a roundabout ....then it refused to restart so it was the long push home mostly downhill luckily