LCGB Forums

Hi - had a couple of starting issues coming back from Ireland with what looked like the carb just flooding too easily when trying to start - c few bump starts later & we were off but .. stripped the carb this morning to clean it out and check the jetting .... it's a 30mm dellorto, running open mouthed with s stage 4 200 lump. So 2 questions are and apologies if they're so easy but

- How far up should the choke rise from the seat when it's pulled on? Does it matter in terms of the fuel getting pulled in if it lifts a quarter or full?
- Currently have a 70 choke jet in it, I'm assuming a 65 or 60 choke jet just means less fuel firing in?

Many thanks -- G.

Brass plunger needs uncover no more than 50% of hole (looking into carb mouth side drilling). This is enough to ensure sufficient suction / vacuum to lift the choke's fuel column but, importantly, ensures enough slack in the cable so that the plunger fully seats when OFF. The rubber tip on base of plunger can otherwise cover the hole but not seat correctly, thereby not blocking off fuel supply and effecting fuel flow. OFF should be 100% OFF.

Cheers Granty

Thanks Adam -- I'll get it back on the bike and do some farting about ... Scott H was my 'pusher of choice' but i can't guarantee him being around at every opportunity .... Got a 65 choke jet coming also to replace the 70. -- many thanks for replying, G

Adam_Winstone wrote:Brass plunger needs uncover no more than 50% of hole (looking into carb mouth side drilling). This is enough to ensure sufficient suction / vacuum to lift the choke's fuel column but, importantly, ensures enough slack in the cable so that the plunger fully seats when OFF. The rubber tip on base of plunger can otherwise cover the hole but not seat correctly, thereby not blocking off fuel supply and effecting fuel flow. OFF should be 100% OFF.

Cheers Granty