I have a 1985 Motomarina Sebring with the Morini engine. I had a mechanic put the Polini 60cc kit on it. The bike has been causing trouble since the kit was installed. Here is how it goes....
I got the bike back from the mechanic with the kit installed and a new #66 jet in the dellorto carb.
I ran it for 15 minutes when i got home and it broke the flywheel key.
I took it back to the mechanic and he put a new flywheel key in.
I took the bike home and tried to start it for 15 minutes, but no start.
I rolled the bike down a steep hill and the engine started at about 15mph.
The bike ran for less than 15 minutes and the engine died.
I tried to start it the next day and nothing.
The mechanic has the bike now and he spent a week looking at it with a Morini rebuild book and he has no clue.
I do know the following things....
i tried running it with the original carb and a new carb ...no fix,
the flywheel key is not broken again,
the points were set to the specs in the manual,
compression is 160, spark is good, all lights work, and the bike is getting gas.