o8 grizzly 700 back fires off and on - Yamaha Grizzly ATV Forum
Grizzly Talk Here we talk about our Grizzlys in general.

 1Likes
  • 1 Post By Greeng0!
 
LinkBack Thread Tools Display Modes
post #1 of 4 Old 04-14-2019, 08:10 PM Thread Starter
 
Join Date: Apr 2019
Location: wellsville, ohio
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
o8 grizzly 700 back fires off and on

hello, I too am new to grizzly central. what brings me here is, I have a 08 grizz 700. when I start it up it runs great like it always does till I get about a mile down the road then it back fires like crazy off and on, till it stalls or close to it. when it does stall, it fires right back up and idles fine, and again I rip into it and it starts back firing. if I let it cool down for an hour or so it runs fine. then it warms up and turns to poop. I checked all connections, took off coil and cleaned it, new spark plug, and adjusted the valves. I do have a hmf penline pipe and hmf fuel optimizer added to it. the settings are to hmf standards. I disconnected the optimizer and ran it stock with no luck of advancement in my problem. also, some times when it back fires and cuts out the engine light will come on for a brief second. its not cool to be going up a steep rocky muddy hill and it decide to take a shit. well that's all I can think of, I hope some one out there has this problem and figured it out. it reminds me of a 2 stroke cutting in and out. its not a constant back fire. itll run great then back fire for 45 seconds then run awesome for a min or two then bad, and the cycle repeats. thanks a lot for reading.
Greeng0! is offline  
Sponsored Links
Advertisement
 
post #2 of 4 Old 04-14-2019, 09:50 PM
 
Chuggy500's Avatar
 
Join Date: Jun 2017
Location: Burnie, Tasmania Au
Posts: 56
Thanks: 35
Thanked 4 Times in 3 Posts
Rep Power: 23
 
o8 grizzly 700 back fires off and on

Quote:
Originally Posted by Greeng0! View Post
hello, I too am new to grizzly central. what brings me here is, I have a 08 grizz 700. when I start it up it runs great like it always does till I get about a mile down the road then it back fires like crazy off and on, till it stalls or close to it. when it does stall, it fires right back up and idles fine, and again I rip into it and it starts back firing. if I let it cool down for an hour or so it runs fine. then it warms up and turns to poop. I checked all connections, took off coil and cleaned it, new spark plug, and adjusted the valves. I do have a hmf penline pipe and hmf fuel optimizer added to it. the settings are to hmf standards. I disconnected the optimizer and ran it stock with no luck of advancement in my problem. also, some times when it back fires and cuts out the engine light will come on for a brief second. its not cool to be going up a steep rocky muddy hill and it decide to take a shit. well that's all I can think of, I hope some one out there has this problem and figured it out. it reminds me of a 2 stroke cutting in and out. its not a constant back fire. itll run great then back fire for 45 seconds then run awesome for a min or two then bad, and the cycle repeats. thanks a lot for reading.


Hi and welcome to GC, some of the other guys here might know exactly what the problem is but my thoughts would be probably fuel restriction, possibly partly blocked fuel filter or injection, would be worth replacing/ cleaning filter and trying a good injector cleaning additive, if itís not that then it could be something in your electronics braking down when hot causing it to run too lean, I think the 08 has its own built in fuel air adjustment via your instrument pod, might be worth disconnecting your HMF and try giving it more fuel via the Yamaha A/F screen, worth a try! I did that with my 10, stopped all the popping and backfire, if youíve used ethanol/ ethanol mix fuel in it and left her unused for a while then thatís most likely the cause of your grief, one of the other guys on here might have some other ideas where to start too, should be able to get her back to her best without too much trouble. Just thinking maybe worth checking your fuel pump, pump relay etc.
Cheers
Chuggy500 is online now  
post #3 of 4 Old Yesterday, 09:02 PM Thread Starter
 
Join Date: Apr 2019
Location: wellsville, ohio
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Changed fuel filter, fuel pump relay, fuel injector, coil, greased all electrical connectors, still runs the same as before. I checked valves and those seem to be in tolerance. I pull the cam shaft cover off and checked the timing, that my friend may be the problem. Looks like it jumped time. The timing chain is loose with the slack adjuster extended all the way out. So I ordered a oem chain, we'll see how it goes next week. Thanks for the feedback back, I'll let you know the prognosis.
Chuggy500 likes this.
Greeng0! is offline  
Sponsored Links
Advertisement
 
post #4 of 4 Old Today, 07:55 PM
 
Chuggy500's Avatar
 
Join Date: Jun 2017
Location: Burnie, Tasmania Au
Posts: 56
Thanks: 35
Thanked 4 Times in 3 Posts
Rep Power: 23
 
Quote:
Originally Posted by Greeng0! View Post
Changed fuel filter, fuel pump relay, fuel injector, coil, greased all electrical connectors, still runs the same as before. I checked valves and those seem to be in tolerance. I pull the cam shaft cover off and checked the timing, that my friend may be the problem. Looks like it jumped time. The timing chain is loose with the slack adjuster extended all the way out. So I ordered a oem chain, we'll see how it goes next week. Thanks for the feedback back, I'll let you know the prognosis.


If your changing the cam chain I would also change the cam chain tensioner guide because that would be worn out too, and I would check your cam bearings as well and possibly your bottom drive sprocket, all these parts usually all need replacing at the same time, you must have a lot of miles on her as these parts normally last between full engine recons although they will be the first things to wear out if you Grizzly doesnít get its scheduled oil changes with good quality synthetic oils.
Chuggy500 is online now  
Reply

  Lower Navigation
Go Back   Yamaha Grizzly ATV Forum > Grizzly Forums > Grizzly Talk




Posting Rules  
You may not post new threads
You may not 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