Hi all I will post pics tomorrow if it's not raining and maybe a youtube video so you all can hear the problem but I bought this thing the other day for $700. Didn't really get the chance to test it out before buying it but he rode it around the yard before I bought it and it sounded fine so I was happy. Well I rode it yesterday and today and it's got some major problems. What it's doing is revving very high at idle (which it didn't do when i first got it) and when you slow down from a fast speed it acts like it wants to die. I dont know much about atv's or carburetors so any tips will be much appreciated. Also what kind of oil should I use?

 

I also just noticed that where the throttle cable goes into the carburetor cap it's not completely screwed in and I dont know how to screw it in without taking the whole cable off where i can twist the part on top of the cap so it screws in the cap

 

Ok here's some pics. I'm also having a hard time knowing (remembering) which way this lever on the carb is choke is it up or down? It ran great surprisingly this morning with the lever up which i'm hoping is without the choke on. In this pic it's flipped down so I could get a better picture with the camera. No Youtube video just yet working on that been busy today. Also want to say this thing doesn't smoke at all, has great compression & all that. Also it's got a weird problem where if you dont turn the gas to the off position it has a slow drip from the bottom hose on the carb what's up with that?

 

Might want to post this in the yamaha section. First of all you want to pull the carb, clean it and see if it has been rejeted for that White Bros slip on. Sounds like the float in the carb is sticking so it would flood and leak. Looks like she had been rolled. Must be hard to ride with the handle bars like that.

 

Ya, those handlebars look messed up !! definately has been crashed/rolled, I would check for other damage.
Now on to the carb, that is not a factory carb, looks like an aftermarket Mikuni round slide replacement carb. Could be the slide is sticking, or the spring under the top cap is weak/damaged. Not having the throttle cable screwed in and adjusted will also make the slide hang up, and even a little lift will raise the rpms a lot. First thing, remove and totally clean that carb from top to bottom, and check your plug to see if it is running rich or lean. To set up the slide, with the carb off the quad, or the air box out so you can see the slide and inside of carb, you should have about 1/8" of free play in the thumb throttle before the slide moves, that way it will go to idle when you let off the throttle. Then, go full throttle and make sure the slide goes up high enough to clear the carb bore,it doesnt have to bottom out on the top of travel, just clear the bore so there is no flow restriction. after that, tighten down the lock nut on top of the carb cap, and you should be good. Set your idle mix at about 2 turns out and set the idle speed. ride it, get it up to speed in 2nd or 3rd gear, then let off the throttle completely, if it "pops" while decelerating, open the mix screw 1/4 turn until it stops popping. If you have to go to 4 turns, you need a bigger pilot jet, then start over again.
For oil, any ATV/Motorcycle JASO rated oil ( wet clutch use ) is fine, NEVER use car oil, it has addatives that will coat your clutch plates and make them slip. I have heard a few guys using Rotella Deisel heavy duty oil with no problems, but I would play it safe and get an ATV rated oil. 10-40 is fine, if your weather runs hot most of the summer, 20-50 will hold up to the abuse even better. Just dont try running that in winter !!.....thick...lol.

 

I use the Shell Rotella. Its good stuff and all the local auto parts store have it.