Hi guys, hopefully you can help, I've had my j1 now for nearly 12 months and still can't sort out it stutter/misfire when on part throttle ie just creeping in traffic but also when exiting corners, I've balanced the carbs to no avail but something tells me it's fuel related still, is there anywhere I could find out what the standard jetting should be so I can strip mine and see if they have been altered, but any other advise would be greatly appreciated, thanks robin

Is it the same hot or cold ? And does the bike ride normally above 3000rpm ?

Has the bike been stood at any time? I would be tempted to dropt the float bowls off, give them a good clean and dose all the bits of he carbs you can get to with carb cleaner. If it's been stood it could the idle/slow speed jets gummed up and as they are really really small are a bugger to clean.

it is the same hot or cold and seams to smooth off above 3000rpm and ride ok, until you roll off then back on exiting corners, ive had the carbs off, stripped and cleaned the jets and float bowls but no change really

Cdi?

Have you lubed/adjusted the throttle cables ?

ive got no other issues with the bikes with regards to battery going flat or cutting out, occasionally when started from cold though I have had a loud bang from the exhaust

the throttle cables are well lubed and free moving

Pilot screws dirty or wrongly set.

Apologies if I'm being stupid but which are the pilot screws?

Where the float bowls are on your carbs there will be a visible gold coloured plain slotted screw in each carb.
These are the pilot screws.they control 99% of the fuelling up to around 2500/3000rpm.

there is a screw then a spring then a washer then an o-ring. Before you remove any ,screw them in completely
just until you feel light resistance and record on a piece of paper how many turns each is at. You can use these amounts to set back to. I'd recommend 2 turns out. If you have an after market exhaust i'd go to 2 1/8 to 2 1/4 turns out. You may need to tweak them slightly to get the best results.

make sure you use a rubber safe carb cleaner when spraying the pilot screw passageway and screw.

I had a feeling it was those, I've tweeked them but never removed them, I'll have a check of them thanks

does any body know what the standard jet sizes should be? im going to strip the carbs again as im not sure the pilot jet holes are clear as it still runs crap at low revs, thanks

I had this exact same problem with a G2 I had many years ago. It was like riding with a power switch that flicked itself over at about 3 1/2 4,000 revs and took off like a scolded cat. 

It was cured by replacing a stick coil that was shorting out. If this is causing it you'll be able to hear the cracking noise at low revs. Get the tank and airbox off and check them out.

I'll have a look at that ta, I've got the tank off already and I've had it running with a remote tank, do the coils just pull out ?