Put an fmf powercore 4 on my klx250s took out the snorkel and rejetted the carb to sea level where I live 128main and 38 pilot, also installed a koubalink t handle air fuel screw.

Now I've took the carb off and cleaned it twice, both times it starts first try and idles right away then about a minute after it runs real rough and wont idle, I was wondering if my float level would cause this ?

Any other suggestions ?

 

Try the simple things first, like the tank fuel lines.

When I pulled my tank once, I put the lines back in on top emissions vacuum line and created a kink. Couldn't get any fuel, well it would get a few drops, run for a minute or so and then die.

Maybe it could be something that simple.

Maybe play with the fuel mixture screw? Maybe it is way to lean or rich?

 

How many turns out on the kouba screw? It should be about 2.5 turns out from firmly seated to start with.

When you start it from cold, do you have to use the choke at all? If not, your idle circuit might be too rich, so there is plenty of fuel to start the bike (like a properly jetted carb with the choke on) and then when the engine warms a bit it litterally chokes and dies To fix that try turning your kouba screw in (clockwise) half a turn to a full turn to see if that fixes it. Given you have removed the snorkle but left the airbox lid on you are not sucking in as much air as my bike which was perfect on a #38 pilot.

 

Don't firmly seat your kouba screw as this could ruin it, and the 38 pilot might be too much.

 

I have the same jetting going on and at sea level also. Don't have any problems really just a minor hesitation once and awhile so I don't think the 38 would be to much Imo. I have the snorkel removed but the airbox lid still on. I did the kinking of the tubes under the tank as well when I put it back on once. It could be that

 

I lowered my float level in the carb and it runs perfect now I just have to test it at WOT see if it has enough fuel.

Also I notices a few pops after a wot rev and I'm at sea level very humid here like 90% + most of the time , the mixture screw is at 2.5 turns, all my hoses are perfect everythings set up accordingly. Thanks all !!!

 

Scratch that now its running like crap surging while idleing and sputtering like crazy or wont idle at all just like before, so I lowered the float even more and still the same,
Im at seal level with the 128 main jet, snorkel removed, slip on powercore 4 and I do have a 38 pilot in and theres nothing else that seems wrong Im so frusterated as ive took it apart nearly 10 times now I only have 50 kms on it and cant even ride it !

 

I even tried goin back to the stock 35 pilot and re-adjusting the float level, still wont run. Really regretting buying this POS and adding over $500 in add ons what a waste !

 

Some things to check and try:

Check/replace the spark plug. (If the bike ran too rich it might have fouled it)
Re-Check the float level.
Replace your Air/Fuel screw with stock and set it to 2 turns out.
If that doesn't work try returning the carb to oem jetting and reinstall the snorkel. Also spray some carb cleaner though all the jets when you have the carb off.

Cheers,

J

 

Make sure you are getting the carb sealed in the boots When you tighten it back up. Also make sure you have the diaphragm seated correctly and that it hasn't been ripped.
Just a couple thoughts.
Good luck.
Dan