View Full Version : popping on start-ups
KBROOKS400ex
06-26-2009, 01:31 PM
i have a 2000 trx 400ex with a hmf slip-on, a k&n, rev box and when i go to start it up it starts but then it will sometimes back fire and blow out black smoke i know it getting to much fuel and i have a 155 main and a 45 pilot and i think its still getting to much fuel any ideas let me know thanks.
BEAVER.989
06-26-2009, 02:20 PM
You're definately too rich. Are you running with or without the airbox lid?
If you're running with the lid on I'd suggest backing down to a 40 or 42 pilot. With the 40 I'd go 2 1/2 to 3 1/2 turns out on the fuel screw... With the 42 I'd try 1 1/2 to 2 1/2 turns out.
You may even want to try a 152 main if you're still using the lid.
RIDEREDson
06-26-2009, 05:22 PM
155 is too rich. So is your pilot. With the lid on, choke, K&N, and slip on I had a stock pilot and a 146 main.
Since I removed the choke and airbox lid I had to bump up to a 152 main and 42 pilot. Just to give you an idea.
KBROOKS400ex
06-27-2009, 12:06 AM
alright thanks for the info ill try out those jets tomarrow before i leave for a riding trip in the upper pennisula of michigan thanks
Powered by vBulletin® Version 4.2.1 Copyright © 2025 vBulletin Solutions, Inc. All rights reserved.