2007 King Quad 450 idle air screw setting

[KCOLLIS]

Hi all,

I have a 2007 king quad 450 with starting/idle/power problems. My two boys had a go at it while I was away at work and now I found that the idle air screw was removed and I don't know about setting it up. I want to set this before I start on the other problems. New fuel pump, new injector, new foam air filter, error code reads -C00. Any help would be appreciated.

[DirtDemon]

Do you still have the screw? I don't believe it is an air metering screw, I think it just moves the throttle position to adjust the idle. Look and see what the screw does, does it move the butterfly valve when you turn it in? If it were me, I would start by screwing it in just short of opening the throttle vavle. If you need to open in up more, you should be able to make that adjustment on the throttle cable adjustment on the bars. Go with the most simple things first, if you don't have a repair manual, get one.l

[KCOLLIS]

Thank you for the answer. It is an air regulating screw in the fuel injector throttle body. It allows more or less air to pass through to the fuel mixture. The manual says not to mess with it but it was already messed with and I don't know the factory setting. I hope someone can help with this.

[DirtDemon]

It couldn't hurt to call a dealer tech and ask them how to set it properly. Don't let them talk you into bringing it in to them. If they won't give up the answer, get a factory Suzuki repair manual, it has all the info that the dealers do, and it is cheaper than an hour of their labor. The crappy thing here is, you need that to be correct before you can even begin to address any other problems.

Can you access the screw with the throttle body on the quad? Would it be possible to adjust it with the engine running? That would be ideal because if you can't find the info, you could just set it to 1 1/2 or 2 turns out from seated and fine tune it with the motor running.

Were you having other problems before your kids started messing with the machine. If you think the injector may be part of the problem, you can take it out and inspect it visually. I have heard of people having problems with cracked injectors. Also, there is a temp sensor in the airbox, make sure the plug is secure and the wires aren't damaged. Probably wouldn't hurt to check wiring on any thing you may think is not working properly. I know I have found several wires on my LT-R that have wear spots on the insulation and I have had to tape them up. Good luck.

[KCOLLIS]

Thanks DirtDemon,

I'm going to call the dealer today. I need to know the factory setting because I was having other problems and need the origional setting on the air screw before troubleshooting the other stuff. Hard to start, rough idleing, and poor power under load is making me think valves but I would like to try some other stuff first. My compression tester won't fit the small spark plug hole so I'm going to try and figure out how to use my vacuum tester on the valve manifold.

Thanks again, Ken

[DirtDemon]

I would agree that your valves may be the problem, hopefully it is as simple as an adjustment.