Honda TRX ATV Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hey everyone I’m new to the trx forums. I have a 1999 trx400ex (all stock) that I need some help with. I’ve rebuild the top end and carb. Carbs been rebuilt a couple times hoping to get it to work right. I set my air mixture screw to stock and the quad Boggs and dies when I get into about 1/4 to 3-4 throttle . So I added more air. About another turn. I got it to run ok for the first time in a while around the block yesterday, however went to get on today and it backfired and bogged the whole time. I’ve been trying to get my 400 to run correctly for over 6 months with no luck. Any suggestions and help would be much appreciated.
 

·
Super Moderator
Joined
·
3,746 Posts
The fuel screw (pilot screw) has little to no effect on performance for throttle openings over 1/8. Here's what the fuel screw affects (rough idle and stalling when letting off the throttle):
4327

Here's how to set the fuel - first, ride the vehicle for 15 to 20 minutes to warm it to operating temperature (do not let idle for 15 to minutes - place a fan in front of the quad to move air across the engine while making the pilot screw adjustment.
4328

From what you describe, the carb is not functioning properly - it probably needs a professional cleaning or you may actually have an ignition problem.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
Thanks for the help I appreciate it! I’m going to mess with it some more and I’ll keep everyone posted! If I can’t get it right by dune season I’m just going to take it into the Honda shop and see if they can go through it and find the problem.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #4
I just ordered a new ignition coil. I’ll let you all know if that solves the problem. It’s also fowling out plugs rather quick. The plugs are black but not wet. Hopefully this ignition coil works if not I’ll keep trouble shooting until I get fed up and take it in.
 

·
Super Moderator
Joined
·
3,746 Posts
I just ordered a new ignition coil. I’ll let you all know if that solves the problem. It’s also fowling out plugs rather quick. The plugs are black but not wet. Hopefully this ignition coil works if not I’ll keep trouble shooting until I get fed up and take it in.
Education costs something and you are learning as you go - you learn from your successes as well as your failures, it's just a more painful to learn from failure. Here's hoping for your success :geek:(y)
 

·
Registered
Joined
·
4 Posts
Discussion Starter #6
Just put on a new ignition coil and does the same thing. I decided it just has to be carb related so I’ll be taking my 400ex to the local Honda shop and see what they find. I’ll let everyone know what the turnout is.
 
1 - 6 of 6 Posts
Top