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.


07 grizzly 700fi runs rough,black smoke out the exhaust

Recommended Posts

Hi everyone how are you.I have a 2007 yamaha grizzly 700efi .One day out of nowhere my atv started to run really rough.turns over fine but i need to press the throttle for it to start and hold it here and there so the atv does not stall out.it does not stay idling.its really choppy at low revs and as i press the throttle it gets better almost normal in high revs.i have the original exhaust and i drilled out the baffle in it for better flow and i also installed a stealth exhaust.stealth exhaust is a extra exhaust and it acts like a silencer.i also noticed lots of black smoke coming out the exhaust. i had this set up for 3-4 years with out a problem till about a year ago. i tried lot of things like: new spark plugs,different spark plugs,new k&n filter,ignition coil,adjusted the valve clearance,swapped ecu,checked all fuses,took stealth exhaust off,drained old gas and put new gas in,and so far had no luck the atv is not showing any error codes.if anyone can help that would be great,thank you.

Share this post

Link to post
Share on other sites

Based on what you have described, here is what the manual says could be the problem(s). I hope this helps you.



● Improperly returned starter plunger

● Loose pilot jet

● Clogged pilot jet

● Clogged pilot air jet

● Improperly adjusted idle speed

(Throttle stop screw)

● Improper throttle cable play

● Flooded carburetor

Electrical system

● Faulty spark plug

● Faulty CDI unit

● Faulty pickup coil

● Faulty charging/rotor rotation direction coil

● Faulty ignition coil

Valve train

● Improperly adjusted valve clearance

Air filter

● Clogged air filter element

Share this post

Link to post
Share on other sites

You are most likely having an injector issue.. It's prolly dirty and wil need cleaned out with injector cleaner .. If not it's your throttle position sensor that's bad .. Hope this helps

Share this post

Link to post
Share on other sites

I appologize, CK may be right, I was looking at the wrong manual. Heres the info from the correct manual:


Electrical system

• Faulty spark plug

• Faulty ECU

• Faulty crankshaft position sensor

• Faulty ignition coil

Valve train

• Improperly adjusted valve clearance

Air filter

• Clogged air filter element

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.

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 Asen_77
      Hi All,
      My name is Asen and I am from Eastern Europe, Bulgaria. Riding a Yamaha Raptor 700R and this is my first Quad wanted for a vey long time :)

    • By Gordon cousins
      I have a 1991 Big Bear 4x4   Shifter on top. Any one know if a  1994 Big Bear 4x4 Shifter on motor can be swapped 
    • By StolenATV
      Taken from my car port around 0330 and was taken by at least 2 people found footprints pushing the quad all the way to the road (80 yards)
      The post 2012 Yamaha Grizzly 700 EFI 4×4 Stolen appeared first on STOLEN 911.
      View the full article
    • By K L Buck Naff
      Trying to replace the carburetor on my 2003 Bear Tracker 250. Two brand new carbs in a row from different suppliers.   Both leak fuel out over flow and intake as soon as I turn the gas on. Any ideas. Am I doing something wrong?
    • By Hondasher
      I picked up a 1997 Yamaha Big Bear 350 2X4 a week or so back in non running condition, apparently they said it needed a new carburetor or a battery, I cleaned the carburetor thoroughly and got it running on idle and without choke now and it shifts into all the gears even into reverse. Aside from making me bounce a little when trying to start out with a bit of throttle the shock suffice to say needs work. Anyways I made a video of it running and would like your opinions on it, as to how it sounds while running. It seems like it has a little whine I'm not sure why that is maybe someone can tell me what it is. Anyways here is the video.
  • Similar Tagged Content

    • By marcuslachance
      I bought a Honda 250sx 1986 but the exhaust is broken. Apparently it's not possible to order a new one. I checked to order one on others compagny but there's noting.
      Do you know which exhaust it's possible to install. Is there a company who sold an exaust to fit on my 250sx.
      Sorry for my english
      Thank you
    • By gyminis
      HELP, i have a 2009 yamaha grizzly 700 yfm7fgpy special edition with a defective fuel pump and am wanting to know how to test it to know if it is defective or not
    • By gyminis
      i have a 2009 grizzly 700,replaced the fuel pump and filter,replaced the spark plug and checked the air filter for a mouse house! it runs then shuts down,wont stay running,does the fuel line need to be primed and air free to run properly or am i missing something obvious??????????????
    • By cheatmaster300
      I am working on a 500 that seems to have me stumped. The quad will start but will only run if I keep pumping the throttle. It smells like it is getting way to much fuel and the plug is always wet when I take it out. I took the carb apart and cleaned it really good twice. Still the same problem. So I swapped the carb with another working quad. That quad runs fine with the carb but the problem quad still runs the same. I swapped the coil this did not solve the problem either. I also checked the timing with a timing light and it seems to be good. I am not sure what I am missing. Any ideas?
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Create New...