Quantcast
Jump to content

  • Do you own an ATV? Join our Forum!

    As a member, you can post in our forums, upload your photos and videos, use and contribute to our downloads, create your own member page, add your ATV events, and even start your own ATV club to host your own club forum and gallery.  Registration is fast and you can even login with social network accounts to sync your profiles and content.

dirtdevil96

Can anyone help me with jetting?

Recommended Posts

I just installed a new full system exhaust and a K&N filter on my '07 Arctic Cat DVX400.It uses a Mikuni brand carb.I installed the recommended 150 main jet before I started it.(Stock is 130)I started the engine and the head pipe turned orange hot.Is this a sign of too rich?Should I go to a lower size main jet or is there another adjustment/jet that needs changed?

Share this post


Link to post
Share on other sites


actaually for most aftermarket exhaust on 4 strokes the head pipe will turn cherry red...ive heard this b4 not a big dealsigns of running rich or lean will be backfiring...

rich will backfire out the exhaust pipe and lean will backfire out of the carb/airbox...hope that helps.. if your bike isnt backfiring id say your fine...

Share this post


Link to post
Share on other sites

I think I found out why it's turning colors.I didn't adjust the fuel mixture screw.On my quad;there's a cap I have to remove(damn you EPA lol)to be able to access the mixture screw.I was told by the exhaust manufacturer that I would only have to rejet the main(they never said anything about the mix screw).I sent a message to Dynojet and they said to get the most power I need to change the needle also.They've been MUCH more helpful than the manufacturer(they even have a Q&A forum-what a waste of my time that was!!).So I think I'm gonna order the Dynojet kit and maybe a couple more things while I'm at it.Thanks to all who replied...

Share this post


Link to post
Share on other sites


Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Topics

    • By ed1228
      Having a problem on my 2006 400. LCD display will not power up. Check fuses under seat seem ok. Is there any inline fuses I should know about....Any help?
    • By Shannon Battles
      I just got a used kawasaki bayou 250 and oil is leaking around exhaust stud are there any quick affordable fixes
    • By dpacapt
      Has anyone disabled the engine brake on their atv, or is it even possible?
    • By jimybud
      Below is a quote from a response to similar question from yesterday: 
      "Easiest thing to check is trash in the main jet.  if it idles fine, then the idle circuit and low speed jet is clear.  if it bogs off idle that's when it's transitioning to the main jet." 
      I will go ahead and open up the carb and check the main jet, but please respond to this post as if the main jet is squeaky clean.
      Below is my post:
      Only starts and runs on Full chock. 
      Does not matter what position I have my "mixture" screw.   Tried it at zero, 1 turn, 2 turn, up to five turns.  Spent a few hours confirming that the position of the mixture screw does not resolve issue.
      Runs great at idle and if I slowly engage throttle, it will rev up as expected.  But, quick rev up or when I am trying to drive it, it spits and sputters and looses power.
      I also use a propane bottle and did not find any obvious leaks, and the vacuum port is hooked to fuel peacock and I also made sure to simply block the port with my finger to see if that would resolve the issue.
      New Carb (after market), New Coil, Fresh Gas.  No leaks at manifold boot, hot battery.  Good gas flow.    Runs too good to be a valve issue, or cylinder, great compression.
      I can move the choke out a tiny bit, and it will still run, but will still bog down when I try to power it up.
      I also have a 250 trail boss Polaris that I require to run at full choke, but it has power at all throttle potions.
      I suspect it is running rich as the choke is on, but will not run with it off.
      Any details would be appreciated.
    • By Michael Thornton
      Why does the 2001 grizzly not have com bearings or something to protect the head.
  • Similar Tagged Content

    • By Aj Hurtibise
      Hey guys I'm new to the Forum I just got a 2000 Honda trx90 looking to make it go a little bit quicker I don't know much about four wheelers but I am a technician at a dealership so I know my way around a motor.
    • By Thumpinhard25
      First thanks for any help guys, new to the forums and it's gotten me this far. I bought a 2001 bear tracker 250 for my family to get around the dirt bikes races. It wasn't running right and had a high idle. Previous owner thought it was a carb problem, so he ordered a new Zoom carb and new intake boot, but it still had the same high idle. ( I believe he had the throttle cable adjusted wrong, because it idled fine when I put it back together) So I tore down and cleaned the stock carb, and it started up and idled fine, but needed to have the choke 1/2 out to run.  I swapped to the new zoom carb and had the same issue. Choke half out bike ran ok. I played with the needle and the pilot screw with no change. ( bike did seem to be running rich though, but didn't get better when I tightened pilot screw or raised meddle) I Took it to the races and once I started bouncing around in the cattle fields the quad started cutting out real bad. It would barely run.  Sometimes it would run with choke off, sometimes choke 1/2, sometime choke full. I cleaned carb again, checked float level, and boots, no change still wouldn't run. Then suddenly it started running ok again.  This makes me believe it's an electrical issue rather then carb. I know there's no air leak, it's been checked, both carbs are clean( I've swapped them out a couple times, it starts up immediately and usually idles fine. But then bogs down/ or stutters under throttle. I saw the post on the guy who disconnected his rectifier and reconnected and suddenly it started working again, which lead me to believe it may be electrical and not carb.  So any advice on what I should check? Any way to test the CDI or rectifier?  Once again, I appreciate your help.  
    • By OmarTrx450er-09
      MY trx has some mods like an full exhaust air filter and an oil filter my lid is on i bought a dyno jet kit stage 2 i read the instructions and changed the main jet supposibly but i didnt change any fuel needel on pilot jet when i turn on the bike its starts immidiatly but starts poopin and crackin on 5th gear when i go fast >>>?? why ...i feel like the bike should get some moore airshould i remove the lid or what??
    • By marioweldinginc
      I know Im detuning but its getting annoying riding with an open airbox. I ordered a closed lid cuz sucking in water is not fun. I have the chain drive apart and im waiting for my 13t front sprocket to come in. That should make up for any torque loss with the closed box right?
      My questions are, while I have the carb apart for its winter cleaning do I have to rejet for the closed lid? It already has a Dynojet stage 2 kit in it. Also should I go back to the colder spark plug (DPR8Z). In there already is a DPR9Z
    • By predrider305
      I was looking into learning how to jet a carb since it seems to be a very important part of the atv world! Found a few good pages about jetting and have a question. How would I increase the jet size on a pilot or a main jet? Would I have to buy new jets or is there a certain procedure to do so on the stock jets? Thanks.
      P.s: try to lean any replies towards a beginners point of view
  • Recently Browsing   0 members

    No registered users viewing this page.


×
×
  • Create New...