jetting size

[Anonymous]

can anyone tell me what size jets would perform well with a vance&hines exhaust system one a gs1000

[KEITH KRAUSE]

The only mod' is the exhaust? Which V&H pipe? Megaphone or ? Stock intake with the airbox lid still on and stock filter?

[Anonymous]

megaphone exhaust system, no airbox just the single filter pods for each carb.

[KEITH KRAUSE]

I have a '79 GS1000E. I installed a Dynojet jet kit. P/N 3304. About $125. It works well with my V&H pipe and K&N ovals. It's up to you. Of course, you can try adjusting the stock jet needle and see what happens. Then you just need mains and possibly pilot jets and/or pilot screw adjustments. What jetting to try also depends on your brand of filters. My suggestions assume K&N's.
I believe the stock needle clip position is #3 groove? If so, raise the needle by lowering the e-clip 2 positions down. This should be the bottom groove. If you still feel hesitation/surging or have a lean plug read at 1/3 to 1/2 throttle, then you need the jet kit.
If the needle is working OK, then I would try 127.5 Mikuni mains or possibly 130.
The Dynojet kit supplies a 138 main which is nearly the same size as a 130 Mikuni main jet. Again, test and get plug reads.
For the pilot circuit, I would try 17.5 pilot jets. 15's are stock.
Then adjust the air screws on the side (not the pilots underneath) for the highest possible rpm you can achieve. Put the bike on the centerstand and warm it up first. Turn two screws in 1/4 to 1/2 turn increments until you hear the rpm's max, then fine tune them. Now do the other two screws. After all four are set for the highest rpm, re-set the idle with the idle screwknob to 1,100 rpm. They will probably end up about 1 1/2 to 1 3/4 turns out. With the larger pilot jets, leave the pilot screws underneath, alone. Test the pilot circuit and get plug reads after cruising a few miles at about 35/40 mph in top gear. You may need to adjust the pilot screws in or out a little. They are sensitive and just a 1/8 turn matters. Out richens the mixture, in leans. Use a good fitting tool. The pilots and side air screws can be stiff and strip easily. If you bottom the pilots for any reason, do so LIGHTLY. The sharp tip can break off inside.
You can also richen the pilot circuit just by adjusting the pilot screws, but with the stock needle, I think you'll need larger pilot jets too.
You should also remove the two floatbowl vent tubes. The bowls will vent easier and the jets will draw fuel easier. With pod filters, remove the vent tubes or you'll experience fuel starvation, especially noticable at sustained speeds.
Lastly, synch the carbs with a vacuum tool to avoid mixture problems. If the carbs are not balanced, re-jetting is too difficult. The side air screws should be adjusted like I said first and the ignition timing set correctly, then do the synch.
All testing should be done after the carbs are synched. If you move the jet needles later, you must re-synch.

[Anonymous]

thanx

[KEITH KRAUSE]

Do me and others a favor and let me know how it goes.

[Anonymous]

when i get around to it i'll let everyone know how it went