When I got my quad it barely idled, and finally got to the point where it would no longer run at all. I rebuilt the top end and honed the cylinder, put in new rings the whole shebang. Its still having an idling problem. It will only run with the choke fully on, as soon as I start to push in the choke it dies out. I tore the carb apart and gave it a bit of a cleaning. I cleaned and soaked all the jets that are in the bowl. Its still not running right.

The only thing that I have not done yet is adjust the valves.

I pulled the plug after it ran for only a couple minutes and its dry and black, so I know it is running really rich. Its really black.

Where should I start to look. I would really like to have this thing on the trail on friday, but its looking like it might be a long shot.

 

You may have answered your own question about the valve adjustment if the carb jets are clean,needle and seat ok or replaced! I've had several that came in like this and had to adjust the valves. This is shim under bucket system and you may be best letting a dealer adjust rather than having to possibly having to get a bunch of different shims (unless you have a shim kit) OPT

 

Would the valves being out of adjustment cause it to run that rich?

 

I've had em come in NOT running at all from tight valves! OPT

 

Yes, I know they can not run because valves are out of adjustment, but I would think that the reason that it is running so rich is because the A/F ratio is rich. I could be wrong, but I guess that doesnt make sense to me. Could the valves be the reason it is running rich?

 

YES tight valves can cause it to run rich! Causes combustion chamber not to seal off completely during ignition!. If you have eliminated the carb completely as a problem and have not had the valves adjusted,this is what I would have checked out. Like I said,I've had several come in running bad,not idling good at all or quit running because the owners never had their valves adjusted. OPT

 

Awesome, thats what I was wondering. It just doesnt make sense in my little feeble brain. Why cant we just stick to EFI? hahaha

 

The Predator is by design a higher maintenance atv, NOT like the self adjusting hydraulic valves on the 700-800 efi and even the 500 carb or efi which just requires "checking clearance once a year or so" under normal use! Shim under bucket systems do require periodic valve clearance checks and adjustments even though they have a variable clearance range.(For example .006-.008 clearance on intake valves, .008-.010 on exhaust clearance) This is not the Predator range,(CAN'T remember off the top of my head!!) JUST an example on this type of system. The ones brought in to me were always TOO tight! OPT

 

what all did you put in it stock change anything from what it was before rebuild. and if you have to pull the choke out to make it run it would not be getting enough fuel running lean or a vac leak somwhere around the carb. if it idles with the choke out but not with it in the choke adds more fuel. if not valves or vac leak might have to tweak carb adjustment

 

I got the valves adjusted and she seems to be running fine now. One of the exhaust valves had no clearance between the cam lobe and the bucket. I dont know about the A/F Ratio. I dropped in a new plug and ill give it a while before I check it.