TOPIC:

Seems to be I sort one thing and then I find something else. Bled the cooling system and all is good. Got a float bowl repair kit and an in line filter and the bike fired right up. Ran it till the fans kicked in and made sure the water didnt come out of the expansion tank then switched it off. Tried to start it minutes later and it wouldn't fire. Left it 10 minutes and tried again and it started, switched it off and switched back on and it wouldn't fire. Any clues anyone?

Hi Stu,
they say here "Life no dey easy Oh"
Sounds like you have a vapour lock when you switch off the engine heat evaporates the fuel in the pipe and filter, it was OK before you fitted a filter When it didn't start disconnect the fuel line and refit it, if there is a vapour lock that should remove it, then change the position of the filter, probably hanging down over the starter motor?
The original fuel pipe are almost horizontal from the tank outlets,
Cheers
Joh

As John said, you have made significant changes to the carburation system so that's the best place to start looking for a problem.

If it's not that then I would be checking the spark. The ignition winding in the stator that supplys the CDI can show up problems when hot as things expand, but that may only apply to the early bikes without the inductive ignition system.

Having owned a variety of old Italian bikes I think I'd check for a good spark anyway.

just spent a bit of time in my lockup re routing the fuel lines away from the exhaust and starter motor. It fired up first try then it wouldn't start again. Left it 10 minutes and it started, stopped it again and the same problem. The only thing I have changed really is the air filter (from a disintigrated foam one to a paper one)so whipped it out and drained the float bolw and it started first time and started every time after that. Looks like it must have not been getting the correct air/fuel mix. Need to decide if I should muck about with the air screw or just get another foam filter.

Foam filters are much more free breathing than paper filters, for this reason you will not find paper filters on race engines, I have 1/2" thick sheet of reticulated foam and make my own gluing it together with Evostick You can re-use the rubber surround of the degraded filter to make a new one
Goodluck
John

Bloody motorbikes, they're just a headache and nothing but trouble.....