Starting Problems

[Lamaddict]

I know it's the carb 28 mm Dellorto. Looks like the plug is getting too wet/ flooding etc. Do I go up or down on the choke jet number? I'm guessing that might fix it. I turn the petrol off before stopping etc to stop it flooding but it's just a tw@7 to start when cold no matter what else I mess with.

[Daggs]

I have experience of jetting a 28mm PHBH on an Imola.
You don't give your set-up details, but i'll make a start.
You need a 70 choke. It's most unlikely you would need to vary that.
You should start with a 50 pilot. Whether you are using open-mouth, remote filtering or a ram-air type, may cause you to vary this.
I run with a gauze filter direct to carb.mouth. It will start from stone cold within three kicks by using full choke and keeping the throttle closed. A lot of folk screw the throttle open when starting and this leads to flooding.

[mick1]

If it starts with a hand or cloth over the carb mouth then it's fuel shortage. to ask about size of choke and jets we need to know the engine cc and other bits of information would be useful.

has this only just started to happen ?

[Lamaddict]

I have experience of jetting a 28mm PHBH on an Imola.
You don't give your set-up details, but i'll make a start.
You need a 70 choke. It's most unlikely you would need to vary that.
You should start with a 50 pilot. Whether you are using open-mouth, remote filtering or a ram-air type, may cause you to vary this.
I run with a gauze filter direct to carb.mouth. It will start from stone cold within three kicks by using full choke and keeping the throttle closed. A lot of folk screw the throttle open when starting and this leads to flooding.

Brilliant! The choke was 70 but the pilot was 55, I put it down to 50 and 'voila'! second/third kick and I'm away. Thanks very much