The ever present jetting problems question - my turn

[Anonymous]

Hey guys, ready for yet another jetting question? Here's where I'm at - '83 GS1100E, Stage 1 Dynojet at recommended settings (3rd notch on needles, 2 1/2 turns out on pilot screws), K&N filter in stock airbox, and Vance & Hines 4 into 1 megaphone exhaust. Here's the symptoms - pops like crazy on decel and randomly while warming up on the choke. The front of the header pipes have noticeably blued, so it's definitely lean. I haven't attempted to synch the carbs yet, so I wanted to know if I should change any other setting first. Should I raise the needles and/or turn the mixture screws out more than 2 1/2 turns? Does the K&N filter flow so much air that I should go with the stage 3 mains? I'd really like to get the carbs dialed in as best as I can since I'm still trying to sell the bike (check the 4 sale forum if you're interested). I bow at the feet of the GS carb gurus for any help. Thanks guys.

[Anonymous]

First of all, how is it running aside from the decel popping and how do the plugs look? I wouldn't go with the stage III mains unless you're running pods. I went with the Dynojet stage III kit with a Supertrapp 4 into 1 and pod filters and ended up turning the pilot screws out 3 1/2 turns and my needles are at the 4th notch. I have been able to cure a lot of the decel popping on other bikes by going with a bigger pilot jet but unfortunately, Dynojet doesn't supply one with their kits. If the plugs are looking white, try turning the pilot screws out a 1/2 turn at a time and see if that helps and you may want to consider raising the needles by a shim or a notch. My experience with DJ kits in the past is that the baseline settings have been quite lean.

[KEITH KRAUSE]

Re: The ever present jetting problems question - my turn

Hey guys, ready for yet another jetting question? Here's where I'm at - '83 GS1100E, Stage 1 Dynojet at recommended settings (3rd notch on needles, 2 1/2 turns out on pilot screws), K&N filter in stock airbox, and Vance & Hines 4 into 1 megaphone exhaust. Here's the symptoms - pops like crazy on decel and randomly while warming up on the choke. The front of the header pipes have noticeably blued, so it's definitely lean. I haven't attempted to synch the carbs yet, so I wanted to know if I should change any other setting first. Should I raise the needles and/or turn the mixture screws out more than 2 1/2 turns? Does the K&N filter flow so much air that I should go with the stage 3 mains? I'd really like to get the carbs dialed in as best as I can since I'm still trying to sell the bike (check the 4 sale forum if you're interested). I bow at the feet of the GS carb gurus for any help. Thanks guys.

You can't re-jet with any accuracy until the carbs are vacuum tool synched. You'll just get all kinds of different plug reads too. After you synch you may not have some of the problems, or not as much. Then, I would try up to a full additional turn out on your mixture screws. 3 1/2- 4 turns out is at their adjustment limit. If this does'nt help the popping then you need to increase the pilot jet size. The blue headers are mostly the needle circuit being lean. The needles need to be raised more. How much? Do what your plug reads at 1/2 throttle position tell you. I save the main jet for last. Generally, the right choice is the main that allows the highest top speed.
SYNCH FIRST, or you're wasting your time.

[Anonymous]

Ah-ha! Synch FIRST, then play around with the settings. I had it bass-ackwards. :roll: Thanks Keith!

[KEITH KRAUSE]

Ah-ha! Synch FIRST, then play around with the settings. I had it bass-ackwards. :roll: Thanks Keith!

You misinterpreted me. I did'nt mean synch first, like there's an order. I should have said synch BEFORE continuing your jetting. On CV carbs, you can make needle adjustments before or after you synch the carbs. Your first post mentioned that you did'nt do a synch at all. That's why I said synch first, or you're wasting your time.
Synching is an important part of jetting that some people don't have done. Then they wonder why they're having problems.
Now if a bike has VM carbs for example, then you always synch AFTER making any jet needle adjustments. So with VM carbs, there is an order to follow.

[Anonymous]

I had same symptons, took to a place that had a dyno, when they put it on it had 86 horse at the rear wheel. When they were done 108. Cost 275 US dollars. Well worth it.