82 honda 185S carb adjust

[jbanes1961]

Hi all, I put a new carb on my 185S. It starts easily and idles smoothly. Problem is when i go from idle to full throttle it has a flat spot and hesitates. On the other hand, if you are at 1/4 throttle and go to full throttle, it is fine. Someone told me to raise the jet needle a notch or two, which I did. Seems to be doing the same thing. I did notice that if i close the choke about a quarter, when i go from idle to full throttle it is resonding better. My question is..what should i try now? Im guessing it is running somewhat lean during the transition. Any and all suggestions would be greatly appreciated. Jeff

[sp8twn]

What colour is your spark plug?

[jbanes1961]

light brown

[jbanes1961]

Okay not much help here.. let me add i replaced the stock chinese main jet with a .100 main jet from an old OEM carb.The OEM carb has a much larger orafice. Not sure what size chinese jet was. Anyway, i still have same problem. When choke is full open i have a hesitation going to full throttle. With choke 3/4 open it is much better. But still lags a little. Would changing the pilot jet have any effect? Or should i just write this problem off as Chinese junk.

[kb0nly]

Turning on the choke richens the mixture, so in turn you need more fuel. Have you tried adjust out the mixture screw a smidge? Get it warmed up to normal temp and then give the screw a 1/4 turn see if it smoothes it out, if not try a bit more, still doesn't help them you might have to step up the jet size. Any other changes to it? Does it have stock exhaust or aftermarket?

[jbanes1961]

Hey kb....I will try the mixture screw. It is out 2-1/2 turns now. No other changes...the only modifications to the exhaust, is that the spark arrester rusted thru and fell off. When you say step up the jet size, are you talking main jet or pilot jet?

[kb0nly]

Well normally for a mid range stumble i would say mixture screw and adjust the needle as well, but i also like to go back and verify the jet sizes are correct as well. Have you checked the float level to make sure its not starving of gas? If the level is just a smidge low it can cause some stumbling as well, but the fact that your higher ranges seem ok tends to make me think needle or mixture. But being at 2 1/2 turns already is pretty far.

Have you got it warmed up and then turned the mixture screw in at slow increments until it dies and then back out until it dies to find the center point of the adjustment?