I just bought a new to me quad first quad in about 10 years. 2003 vinson 500cc 4x4 automatic decided to go through and do the maintenance.
new plug
Oil/oil filter
fuel filter and line (tractor supply)part
​​​​diff fluid
so before I put the fuel filter on I decided take it for a ride after doing fluids and spark plug I noticed it'll back fire out the exhaust after getting on it only pops once didn't do it before hand curious what you guys think would cause that I can't see changing spark plug would be a bad thing? Also this my first automatic are they normally noisy seems to chatter quite a bit used honda motor cycle engine oil 10-40 .....any tips or advice on taking care of it/mods would be appreciated also

 

The backfiring is caused by unburned fuel loading up in the exhaust.
I used to do it on purpose on my motorcycle by hitting the kill switch while going down a hill, then turning the switch back on. Always a loud bang until I blew my muffler off one day LOL

I’d say that replacing your plug may very well solve this issue.

As for chatter, without hearing where it’s coming from it’s hard to pinpoint.
Could be a chattery clutch, or valve adjustment.
When I bought my 03, I had to replace the clutch pilot bearing in the right side engine cover. It was making a hell of a noise.
See if you can narrow down a location and we can help you out a little more.

 

I use do that to lol same thing happen.

yea I figured it was fuel building up just wasn't sure what was causing it since I just replaced the plug it'll pop once right after I get out the throttle. The noise coming from the clutch just wasn't sure if it's normal or not first automatic

 

You may be running a little on the rich side.

Also if you pull that side cover and the chatter goes away that will pretty much answer if it’s that bearing.
I gotta say getting that old one out was a SONOFAGUN! I have read you can heat up the case and the bearing will come out easier but I saw no way to get a grip on it.
I ended up using it a die grinder to cut through the outer race and then removing it in pieces.
Bearing and seal was only about $30 total so not too bad.

 

I'll check that bearing I could pull the cover off and run it? I'm not real sure about the back fire seen on the net people saying to play with the fuel air adjustment days it running lean think I'm gonna put the old plug back in see if it'll back fire go from there

 

When you pull out the old plug, check the color. tan is good, grey would be lean and black would be rich. If it is in fact running lean, you need to address that before permanent damage. A crack in the boot between the airbox and the motor could be the culprit.

 

the old plug when I replaced it it was black. didn't see a Crack in the boot I'll check it out better in the morning been pretty cold here didn't mess with it today runs and idles pretty good

 

You can fire it up and rev it a bit with the cover off but I wouldn’t drive it. Risk of getting a pant leg caught up in the clutch.

 

One cause of backfiring is a loose exhaust. Some bikes are prone to it, can't say the Vinson is. Honda 450FMs are so bad they blow the baffles out. Those front tyres look a bit wide, bet they make the steering heavy.

 

I don't got to many miles on it myself little rough turning in rough terrain (old cattle pasture ruts from hell) but so far its not to bad.

I was reading on the net sounds to me like maybe air/fuel mixture anyone know an approximate setting for this?