2005 Wilderness 250U, does anybody know about a carburetor controller, a little black box with 4 wires

 

What is a carburetor controller? I've never heard of such a thing.

Automatic choke maybe? But that is only two wires going up to the carburetor.

Four wires?

Let's back up. You have a black box that has four wires that does something. Can you post pic's in your album, or post pic's via a picture hosting service such as www.photobucket.com, or post a link to a picture on the internet that shows this module?

How is it that you think this 4 wire module controls the carburetor? Is it direct wired? Is it connected via mechanical linkages? I'm confused...

So maybe a more appropriate question is:

What problem exactly are you having? Doesn't start? Doesn't crank? Has no power? Only starts on alternate Sundays? What?

 

Lynn, thank you for your response. Sorry I was so vague. When I got this thing the man handed me 2 black boxes, a CDI with 3 white connectors and a little black box with a hole burnt in the side of it, 4 wires, one connector. Haven't tried to start it, the man said it wouldn't run because of these. Wiring diagram from Baja Motorsports LLC shows this part and calls it a carburetor controller. It is 2 1/4" long and 1 1/4" wide and one inch thick. If I knew how to send a photo, I would, or I could e-mail photos to you if I could obtain your e-mail address.

P.S. 2 wires go to carburetor. Probably automatic choke. Somebody said it could be related to California smog stuff. Thanks for your help.

 

Regarding carburetor controller, the black wire and yellow/red wire go to choke. Orange and brown wire go to rectifying adjuster and CDI. Picture of wiring diagram and electrical component in Photobucket under green15350. Hope this helps. Thanks green15350

 

Oh wow. That photobucket stuff helps a lot....

On your photobucket stuff: If you go to your photobucket account and click on any of your pictures you will see a menu that has four link items that you can select:

1) email & IM
2) Direct Link
3) HTML code
4) IMG code

Click on the "IMG code" and you see that the link data ([IMG]http://blah blah blah....) is copied into your paste buffer.

Then in your post you simply paste that info in like this (right click and select "paste", or use the keystroke "Cntl-V") into your post. It will look like this to you in the post editor:

[IMG](but not this part) http://i1353.photobucket.com/albums/...ps4a8b779e.jpg[/IMG]

But I deliberately screwed the above link up by adding "(but not this part)" so the link is messed up and can't be expanded. Here is what the link looks like (once posted or previewed) when the link is valid and works:



See how that works? The images above are from your public photobucket account.

I'm going to link in another image [IMG] link from your photobucket account:



Before I can tell you what the carburetor controller's purpose is we need to talk about automatic chokes (more correctly called "bystarter valves"). Unlike traditional chokes, where the fuel/air mixture is raised when the engine is cold by choking off the air supply with a butterly plate, the bystarter valve works by opening up an extra fuel passage to deliver more fuel when the engine is cold (leaving the air quantity untouched). Either way does the job. It's the ratio of fuel to air that needs to be enrichened - either by decreasing the air, or increasing the fuel.

So when the engine is cold the bystarter valve is open, allowing an enrichened fuel supply to help start up and run a cold engine. A heater in the bystarter assembly is connected to 12 volts when the engine is running. It heats up over a few minutes, heating up a wax pellet, that expands and pushes closed the bystarter valve - shutting off the enrichened mixture. This wax pellet idea is very similar to the wax pellet that opens and closes your car cooling system thermostat based on water temperature. In the bystarter case the idea is that a running engine will keep that heater hot all the time (after a short warmup period) when the engine is running, and keep the enrichened fuel circuit shut off fro the duration of the ride.

I hope all that background makes sense. So really all you need to do is apply 12 volts to the bystarter valve (the carburetor wires - 12 volts and ground) when the quad first starts up. You don't need a "carburetor controll module" for that. Just hook the choke (bystarter) up to switched ignition power. It will work just fine. Turn on the ignition, start up the quad, and the bystarter warmup sequence goes though the proper motions.

But there is a possible problem. Think about this scenario: You turn on the ignition switch, don't start the quad yet , and start talking to a beautiful lady on a king quad wearing a bikini. Time goes by, and now your both ready to ride. But your bystarter valve has been powered now for how long? It's long since shut off and your enrichening fuel path, and her quad starts and your won't because your running way lean on a cold engine with no "choke".

But how likely is this scenario? I have seen bikini clad women on king quads, but never have they distracted me enough to forget to start the quad right away after tuning on the ignition. Most people turn on the ignition, and then start the quad right away. If this is your situation then throw the carb controller away and bypass it.

So what is the carburetor controller doing? It's preventing 12 volts from being applied to the bystarter (choke) *unless* the engine is turning. It does this by looking at pulses going to the ignition coil from the CDI. So if your ignition is on (applying 12 volts to the carb controller), and no pulses are going to the CDI (because perhaps you're talking to the bikini girl) the choke (bystarter valve) is not powered because the controller prevents that. But when you do finally start cranking the controller allows the 12 volts to choke/bystarter. And all is well.

Does all this make sense?