Stock 01 400ex bogging - Honda TRX Forum
 
LinkBack Thread Tools Display Modes
post #1 of 4 Old 09-15-2019, 04:51 AM Thread Starter
Junior Member
Feedback Score: 0 reviews
 
Join Date: Sep 2019
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Stock 01 400ex bogging

Hello everyone,

I’m knew here and tried the search feature but nothing was specific to my issue. So, I have a 01 Honda 400ex. I purchased it a few months back and it rode fine.

After a few weeks of sitting, the OEM carb started to leak fuel. I tried cleaning it up and went through it. It continued to leak and bogged if I tried to smash the throttle.

I opted for an aftermarket carb in the hopes that I would momentarily alleviate the problem while I rebuild the OEM carb. Now, I installed the carb and it runs and idles great (no choke needed).

However, it boggs the same as before. If I smash the throttle, it boggs and dies. I replaced the spark plug and it was black (rich?). I took of the air filter and lid and it still does it.

I’ve had great luck with aftermarket carbs in that they are essentially ready to run right out of the box. I don’t see or hear any air leaks and sprayed some carb cleaner around the airbox and nothing.

Anything else I should do or check? Thanks!
Sponsored Links
Advertisement
 
post #2 of 4 Old 09-15-2019, 06:10 PM
Super Moderator
Feedback Score: 0 reviews
 
Join Date: Jan 2011
Location: Smack in the middle of Illinois
Posts: 2,960
Thanks: 5
Thanked 291 Times in 286 Posts
Most generally starting without choke indicates one or both of two things; float level is too high or the idle circuit is jetted too rich.

Bogging at full throttle can be either too rich or too lean provided you are not experiencing some sort of ignition problem. The 400EX has an AC excited ignition - it does not need a battery to run - with what you describe, it's possible the ignition is becoming weak and spark goes away at high RPM or when under load. The fact the engine performs normally at low speed means the CDI unit is good and the pulse generator which signals when spark should occur is working, that leaves the coil, spark plug, plug cap, stator and flywheel.

Usually when a flywheel goes bad, it works better at high speed than at low speed. Coils can go bad in many ways, but the coil is just a low amperage/high voltage transformer and it's pretty durable - it's usually the last thing that goes bad spark plugs fail frequently, plug caps fail more frequently than coils and stators fail at a relatively high rate.

If you determine the problem is electrical and not carburation, install a new stator first.

Since the carb started leaking while setting, attack the carb as the primary source of the problem. Question is why did the carb start leaking while setting? Did the petcock fail due to alcohol damage to the seal? The only other way the carb could start leaking while setting would be if the fuel was not shut off. Not shutting off the fuel will lead to carb damage from water (carried in with alcohol), from Algae (grows in the water), petroleum distillates (what is left after gasoline evaporates) and corrosion caused by oxygen and all the other stuff in the carb float bowl. Sometimes if the carb is over rich, you can shut the fuel supply off and as the level in the float bowl is depleted, it will start running better and runs best just before it is completely out of fuel. If it's lean, you might try putting it on choke to get it to run better. If putting on the choke makes it immediately worse, then it's probably over rich.

If you have had luck with aftermarket carbs, you are part of the minority - I have scrapped new after market carbs in favor of rebuilt OEM carbs when the POS Chinese copy failed to perform properly and the jets were unmarked and had odd threads making rejetting nearly impossible - I have decimal metric drills for rejetting Chinese carbs, but many times I end up junking them and reverting to an OEM even it I have to get it used.
Here 2 help is offline  
post #3 of 4 Old 09-15-2019, 09:13 PM Thread Starter
Junior Member
Feedback Score: 0 reviews
 
Join Date: Sep 2019
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
I appreciate your reply. I agree in that’s this issue may be ignition/spark related. I say this because my OEM carb and non OEM carb performed exactly the same minus the OEM carb leaking.

You are also correct in pointing out why the OEM carb leaked. I mistakenly left the valve open and it caused the issue (I know better now). I plan on rebuilding the OEM carb, but want to sort this bogging issue first.

Any tips of testing the ignition components you mentioned? Also, say we rule out ignition and carb, anything else I need to look for? Thanks!
Sponsored Links
Advertisement
 
post #4 of 4 Old 09-16-2019, 05:14 PM
Super Moderator
Feedback Score: 0 reviews
 
Join Date: Jan 2011
Location: Smack in the middle of Illinois
Posts: 2,960
Thanks: 5
Thanked 291 Times in 286 Posts
Other than carb and ignition - a restriction in the intake or the exhaust are possibilities
Here 2 help is offline  
Reply

  Lower Navigation
Go Back   Honda TRX Forum > Honda TRX Discussions > TRX General Discussions

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Honda TRX Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome