310 jetting

[jcas]

I just installed an ESR 310 on my 87R. It has the mid/top port, ESR cool head w/ 19cc dome, trx6 pipe, boyeson c/f reeds, k&n w/o lid, and 36mm carb. The jetting is 178 main, 50 pilot, air screw 1.5 turns out, and needle at the 5th (bottom) position. The motor seems to run out of air/fuel when maxed out at 6th gear, it starts to sputter. Other than that, it's a monster. The spark plug is cardboard color, br8es. I live in california, central valley. I don't think the jetting is correct, any suggestions?
Thanks

[methyman]

It could be a couple of things like the plug gap. Weak ignition spark. With higher compression with stock ignition you need to close the gap of your plug like to .015. I had problems when I when with a 18cc cool head dome. I jetted up and down but still didn't run good till I regapped my plug. Try regapping your plug and see what happens. Jetting sound to be almost spot on to me or very close.

Later

Matthew

[jcas]

That was it! Once I changed the gap to .018, it ran perfect. Thanks for the help.

[methyman]

What was happening was the higher compression was blowing out the spark. Glad I could be of assistance to you.

Later

Matthew

[310ESR]

Hey jcas, I live in central california and have the same set up, exept for two things. First - CR 250 ignition , what a difference, spark is never a problem any more. Second - 38mm carb with 182 main, 50 pilot, 3rd clip down, 2 screws out. The cr ignition will lose you some grunt off an idle, but since I live here too we both know there not many woods areas to ride. Just my 2 cents