Jetting issues and pilot screw location?

[Anonymous]

OK, carbs on , carbs off, rinse and repeat...
trying to dial in my 83 gs1100E with single replacement cone filter in place of the airbox and Yoshimura 4into1, painful experience so far.

At this point, I am running mikuni 130 mains, the stock stock pilots and I have my stock needles shimmed up about 3.5 mm, I have tried to set the air screws ( the ones on top of the outlet side of the carbs, but to max the idle, I have to put them about 3 turns out.

On riding the beast, it kid of stumbles off idle, tehn starts to pull hard at about 3K, but I am getting a lot of popping on decel as well.

On reading other posts (jetting seems to be a popular topic) I have seen mention of air screws and pilot screws, is this something I should be adjusting as well? if so, where is it?

any other suggestions would be gratefully accepted,

TIA
Derrick

[pano]

The screws at the top outlet side of the carbs are the pilot screws. I think people have refered to them as pilot, air or mixture screws.

Did you check the float height? When it pulls at 3k does it pull all the way through the rpm range?

Does it run differently when cold verses it warmed up? Cold being choke off and idling normally, warmed up being well warmed up.

When I was jetting my bike (dynojet kit and individual filters), I would think I had it right and then once it warmed up it would sputter when acceleration off idle and pop on decel. Raising the needles seemed to be the cure. FYI the stock needles are definately fatter than the dynojet needles.

if you could swing buying a kit it may save you some hair

[Anonymous]

Hey Pano,
You may be right, when i can swing the cash, a kit may be the ticket. If for nothing else, to get a set of adjustable needles.

I have not noticed a difference between warm and cold, but I have been messing with it for two days and have not really ridden much.

I did not check the float height, but cnce it comes on at 3K, it pulls hard all the way to the redline.

I have tweaked the needles again, I realized (duh) that shimming the needles was not doing any good because the retaining piece sets the max height. I wil test ride in the morning and see how it goes.
Do the jet kits come with new retaining rings or caps that allow the needle to sit higher?


thanks,
Derrick

[KEITH KRAUSE]

Hard to say how much your intake increases air flow. Not sure what stage jet kit would best match your intake set up either.
On your carbs, you have mixture screws. Turning them out increases the mixture of fuel and air. This is considered richening the mixture. Only the VM carbs have true air screws.
Generally, if your mixture screws have an effect on your "highest rpm" adjustments, and you haven't turned them past 4 turns to achieve that, then you shouldn't need to increase the pilot jet size. But I've seen exceptions.
Shimming seems to create more trouble. I always go with jet kits.
You have to SYNCH the carbs too as an important part of any re-jetting.

[Jethro]

Do the jet kits come with new retaining rings or caps that allow the needle to sit higher?

The jet kit will come with a new needle that has a different taper and notches in the needle shaft that accept a circlip which can be moved to either raise or lower the needle height.