I had a 41mm FCR Keihen Carb installed on my Honda 400ex along with a 440 big bore kit (11:1), cam, and Big Gun Racing Exhaust system. During the spring and summer, I had no trouble getting it started. Now that fall is here, I have not been able to start it. I have had to be towed and then pop it into gear to start it. After it runs for a minute or two, I don't have any trouble at all starting it after that, until the next day. This Carb has no choke on it, only an idle adjustment. I even tried removing the air filter and covering the air hole up during starting, but that didn't help. I don't race my quad in competition, but I do ride regularly and ride it hard. Is there anything I can do to this carb to help my cold-weather blues starting this thing, or should I invest in a different carb with a choke? Thanks!

 

have you tried holding the throttle wide open and start at the same time.

 

Puppetmaster,

I am running the same setup, it just sounds to me like it needs to be rejetted. Jetting mine took me forever, but now it starts and runs perfect. Just tinker with it for a while.

~Team440ex

 

a slight reduction in main jet size will help...if you are using an aftermarket ignition box change over to the stock for initial start-up and warm-up the ignition curve in the stock box starts a cold bike much easier

braaap!
JW