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  1. 400EX Issue with Aerated Oil - Running Hot

    Hi there, I'm trying to run down a problem with aerated oil and I'm running out of things to check. Any advice would be appreciated. First question: This can't be normal right? After warming up the bike for 5-10 minutes, shut it off, check the dip stick or drain the oil from the oil tank...
  2. 400ex enough adjustment in carb means no need for jetting?

    Hi, I have a 100% stock 2002 400ex, I still have the stock exaust and no plan or money to get an aftermarket slip on. The other day I took the tip of the muffler, and I really liked the way it sounded, it was a lot deeper then stock, and sounded great under a load. My question is, i rode it...
  3. engine wont stay running after rebuild on 2007 400ex

    rebuilt the top end on my 2007 honda trx400ex recently because it was blowing a little smoke and now it wont idle at all I turned the idle adjustment screw all the way in and it still will not idle it will idle if the it is choked but not when the choke is off.
  4. 2003 400ex pop sound only in 1st gear

    2003 400ex FOX Podium shocks Yoshimura full exhaust K&N filter DynoJet Stage 2 Jetted ProTaper handlebars ProTaper grips I have a pop sound only in 1st gear. Chain has 1 1/2 play in it. Any suggestions?
  5. 400ex tuning problems

    I need opinions on my tuning: I've got a 2000 400ex, original motor, wrapped header, oil change. Rebuilt the carb and adjusted valves. After a lot of trouble with backfiring through the carb (signifying really lean) I'm running a 42 pilot jet and a 150 main jet. This helped a lot, but I'm still...
  6. Jetting in Colorado

    Dyno/Tuning Room
    I know that there is a million different threads on this. However each set up is different. When I purchased my quad I was in TN and now I reside in Colorado. My quad seized up on me since I have been here. I have since rebuilt it and now I am in need of information on jetting for my altitude. I...
  7. Green Wire Mod?????

    Has anyone ever tried this mod? does it actually work? is it worth it? will it work on a 06' 400ex?
  8. Somebody please help before i throw my 400 out the window

    TRX General Discussions
    My 02 400ex has nothing aftermarket besides a big gun es exhaust just the slip on. I recently got my 400 back from the shop it sat for months there not started it wont start i cleaned the carb and set the jets to normal settings first if someone can get me all the jet specs like how many turns...
  9. 400ex safety switch problem

    Site Issues, Bug Reports & Suggestions
    I have a 02 400ex and my safety switch by the shifter broke and i have no ignition or lights. Ive connected the 2 clutch lever wires together and still nothing. Is there a way i can bypass this or no
  10. !!!!!! Used 400ex atv tires for sale !!!!!!!

    For Sale
    I've got a full set of used tires for sale! TIRES:* FRONT TIRE (FULL SPEC) 2 x Ohtsu® 22 X 7-10 REAR TIRE (FULL SPEC) 2 × ITP HOLESHOTS 20 X 11-9 These still have 40% tread available. Pick up only! Northwest Georgia. I have pictures available.... Call or text 678-770-2518 Chris $100.00 or best...
  11. 400EX Setup/Repair

    TRX General Discussions
    Hey all, just recently got an 07 TRX400EX. Nice quad, but needs some work. Figure this is a good place for me to get some help! Things the quad needs: 1.) Brake light works fine when motor is off. Once motor is on, brake light flickers at best -- mostly doesn't work. 2.) Suspension sits way...
  12. 400ex high compression piston

    I'm going to be rebuilding my 400ex I want to put the highest compression piston possible in it and the largest diameter possible. what brand and where do I get it?
  13. 400ex top end rebuild

    I just rebuilt the top end on my 400 ex. Was burning lots of oil. It had white brothers exaust and k&N air filter, 38 pilot and 160 main jet. I bored the bike .20 over and put in a high comp 11.1 wiseco piston. I also put in stage 2 hotcams. Now, I already changed my main jet to a 172 which...
  14. Trx 400 Carb Problem?

    I have an 05 Trx 400ex i bought off craigslist The only issue are the back breaks (currently bleeding them) and the carb leaking. To the right of the yellow choke, and hose, you can see a small nozzle. There is a tube that is long enough to fit around the nozzle shown here This tube leads...
  15. 2002 400ex dies full throttle

    I just bought a 2002 400ex off a guy on Craigslist. I have only drove the quad around a little, seems to be fine. But today I took it down the road full throttle, and at top speed, I pulled in the clutch and stoped giving it gas and it dies. So once I stop, I start it up again, and runs fine...
  16. 400ex low compression

    TRX General Discussions
    I just bought a 2002 400ex for $1450. It started, idled fine with choke to start it. Then it idled fine after. I let it warm up, then shut off the gas. I plugged the compression gauge in and put it full throttle, then let it crank. It only showed 90psi. So it's low. But it starts easy and no...
  17. New guy with problems! Lol

    New Member Introductions
    So I just got my first bike. Which is a 2012 Honda trx 400x and it's really good shape just needs new tires and baffle put in it... I just got it yesterday and rode it today around some Hills and things, and I noticed when I am going up a steep Hill I'm giving it gas and like bogs down like it...
  18. Maintenance for 2006 TRX400ex

    Maintenance / Important Information
    Hello, I am interested in buying a 2006 TRX400ex. The owner told me it needed a new battery and rear fender. He sent me some pictures of it and it is the all black model. The tires looked fairly worn out, the exhaust looked aftermarket or tampered with (possibly he removed the spark...
  19. 400ex Carburetor in a 350 Raptor?

    Site Issues, Bug Reports & Suggestions
    Hey guys yes the title says it lol. My girl Friend has a 350 Raptor and it needs a Carb Rebuild. But, Instead. I'm thinking of just getting her a 400ex carb installing that for a bit for more power as with a port and polish job to. Because thinking about it I noticed on the 350 Raptors they...
  20. 2002 400EX rear shock replaced by 450r shock?

    TRX General Discussions
    I just bought a 2002 400ex and the rear shock blew out riding down the road. I was wondering what year and mods I need to do to make A 450r shock work.