Yamaha Grizzly ATV Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Hi I see there is a lot of you on this site and I’m hoping someone can help me figure out what’s going on.. this morning I started my 2000 Yamaha kodiak 400 fried right up didn’t ride it let it idle for about 2 minutes and shut it off. One hour later I tried to start it and and it won’t start just turns over and backfires.. some times loud like a gun shot. Tried and tried just won’t start. I checked the plug it was wet with gas cleaned it off tried again same thing only a backfire. Tried this multiple times. I then checked for spark. It was sparking great. I then checked the carb a little turned fuel off and opened the bowl drain gas came out then stopped I closed the screw and turned gas back on. I like to try to fix thing myself iv learned a lot about this atv since I’ve had it but this has me stumped.. any advice tips? If I know what the problem is I can probably fix it Hopeing a few of you have had this same issue.. ran great an hour before just suddenly decided not to start.
 

·
Registered
Joined
·
5,543 Posts
Classic symptoms of a sheared flywheel woodruff key. I won't say that is a definitive answer, but it sounds like it to me. I have replaced several over the years. It's not a real common thing to happen, but it does happen. I've even had one of my own shear on a 1994 Kodiak 400 I owned years ago.

You must pull the flywheel to check it. Doing a simple timing check will do no good as the timing marks will still all line up.
 
  • Like
Reactions: thrashingcows

·
Registered
Joined
·
7 Posts
Discussion Starter #3
Reply

Ok I will start with the key I did some research on it and sounds like you might be right. Thank you. If you don’t mind I have a few more questions I know it’s behind the pull start and stator cover looks pretty easy to get to my question: is there oil in there? Will I need to drain the oil first? and is there a gasket on the cover that will need to be replaced? Sorry if these are noob questions I’m learning and appreciate your help.
 

·
Premium Member
Joined
·
7,913 Posts
Hey...Nate16...Welcome to GC from Wisconsin.

Agree with dezz...

Would be best to drain and change out the oil there is a gasket that you will need.
You should download a service manual or check out some youtube vid's.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #5
Reogem

Hey reogem thanks for the reply.. also in Wisconsin.. Stevens point area.
Hoping this woodruff key solves my issue. key is ordered and now that you said something I ordered the gasket as well thanks. Sucks I have to drain the oil just changed it a month ago but it’s fine just want it running again.. I watched a few videos on YouTube not much out there on the flywheel for this atv I’ll look into a Manual thanks.
 

·
Just wanna ride!!
Joined
·
5,518 Posts
Welcome to GC.
 

·
Registered
Joined
·
269 Posts
If you started it on choke & let it idle with the choke on the plug probably fouled, try a new plug & see if that helps, fouled plugs can spark well when tested but play games when under compression.
 

·
Registered
Joined
·
800 Posts
That sucks man. At least oil isn't super pricey. I have never heard of one doing that. Good luck! Let us know how it turns out.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #9
Guipago

Hey guipago.. yea the plug was my 1st thought. Used to have a 3 wheeler that fouled plugs for no reason. Didn’t know even if it showed good spark it could be bad in the motor. I will pick up a new plug to maybe try that before I tear into this thing. Thanks for the advice.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #10
Grizzcrazy

Right.. it sux but at least oil isn’t super expensive. Yea I plan to start working on it this Thursday after work I’ll definitely come back on here and let you guys know how it went and hopefully help the next guy that runs into this issue
 

·
Premium Member
Joined
·
7,913 Posts
Nate16..to save the oil you can place 5 gallon buckets or whatever you have under each wheel on the left side before you crack it open. I've done this when replacing stators.
Sometime it's important to change out the oil if there is a chance that some debris got into the oil.

I live and ride in Birchwood.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #12
Thanks guys

You guys hit that thing right on the head pulled the flywheel today sure enough the woodruff key is in two pieces thanks a lot you guys are awesome. I can’t put it all back together right away still waiting on parts but I’m sure she’ll fire right up. After I get it all back together I’ll post a detailed message on symptoms and solution for the next guy.. thanks again
 

Attachments

·
Registered
Joined
·
7 Posts
Discussion Starter #13
She lives

Got it all put back together today fired right up thanks again guys.. the following is for the next guy.. 2000 Yamaha kodiak 400 ultramatic 4x4. I started one morning fired right up let it idle for a few minutes and shut it off no issues. 1 hour later I tried to start it again it wouldn’t start turned over but only back fired sometimes Quiet sometimes loud like a gun shot.. while holding the starter down turning it over if I pressed the throttle it would make a weird clicking noise not sure if that’s related but it happened. Maybe you will have the same symptoms and it’s a different issue so start small. Spark plug, fuel if that isn’t the cause... woodruff key on the flywheel may be Sheard like mine.. Fly wheel is behind your pull start and stator cover not to hard to get to but you have to drain oil and coolant the water pump is on the stator cover need to disconnect hoses to pull the cover. Things you will need.. oil, coolant, woodruff key, stator cover gasket, fly wheel puller I used a duck foot one, and a torque wrench. Torque specs for stator cover is 7.2 ft lbs. the flywheel bolt is 36 ft lbs. I will include a picture of specs and parts hope this helps someone in the future.
 

Attachments

·
Registered
Joined
·
5,543 Posts
Now that's the proper way to end a thread. Much appreciated for doing that.
 
  • Like
Reactions: thrashingcows
1 - 14 of 14 Posts
Top