So I have the above mentioned bike, the problem I am having with it is that, the bike will only run with the choke on,as soon as the choke is off it dies. Pulled the carb apart checked the carb for anything clogging the carb, or anything dirty in the carb. the bike is also jetted,with an open airbox. I'm wondering if anyone here can guide me in the direction of how to properly tune the carb, and if anyone has any ideas as to where to start diagnosing this problem?
thanks in advance.

 

It sounds like you could have an issue in your needle placement. The link below will take you to a fairly short but rather educational article I have referred people to in the past. I hope it helps...

The Jetting Guide

 

Hi,

Exhaust still original? Sometimes incorrect jetting don't bode well with stock pipe. Depends on jet size but could be flooding due to poor breathing...

How's compression? Burnt valves and back pressure could also affect performance.

Is there an "oil sweat" in the air box? this shows sump pressure and is also culprit cause.

Rotten gas?

Fouled spark plug? Ignition often overlooked as cause is mostly confused with symptom.


Good luck and let us know what the gremlin was to teach us more and share better experiences.

 

I had the same problem with a 300ex that sat a while, no idle unless choke was on, or you gave it a little throttle, turned out the pilot jet was plugged (VERY tiny holes) and the passage from the pilot to the carb throat was plugged. Without the pilot jet or passage feeding fuel, no fuel gets into the carb, so it dies as soon as you take the choke off, which is mostly an enrichment port on most carbs, so it supplied the gas the idle circuit did not. Pull the carb, remove the pilot jet, you may need a fine wire, like one strand off a wire brush to clean it out, then take a carb spray with a straw and put it in the pilot port and make sure you see spray coming out in the carb body.
With an open air box, might not be a bad idea to go up one size from stock on the pilot, I know it helped the 300ex with an aftermarket exhaust and modded air box lid.