[kcarel]

I just recently bought a fourtrax 250 and it came with some issues. First and foremost, the ATV has sat outside for the last 12-14 months without a single attmept to start. It last ran in summer of 2009.

Initally, we couldnt get it to start....period. Wouldnt try, all I hear is the flywheel spinning. The electric start is broke and battery is essentially toast (other than it lights up my headlights and neutral lights just fine). So I am kick starting it. After probably 50-100 kicks, no avail. I pulled the spark plug. Held it up close to the motor and I get spark, so ignition is good. Checked the filter, no debris in the air box and the filter has plenty of air flow. So, I took a straw, dipped it in a gas can and fed the motor directly in the spark plug well. Reinstalled the plug and wire and vroom vroom vroom. Starts up almost instantly from the first and second kick. This is all with no choke. I've tried choking but I'm not even sure if the choke works. Anyway, if I dont keep reving the motor, it will die as the rpms drop to 0. In other words, it wont idle. Keep in mind this is after it has been running for 10-15 minutes. Should be fully warmed up, so choke should not an issue wouldnt you think?

To drive it, I let the rpms drop low right before it dies and knock it into first gear and give it throttle and it will take off. I can shift just fine to all gears and back down to neutral, no problem. The ATV is probably one of the fastest 250s I've been on. Acceleration is very good but my only problem is starting it and letting it idle without dying. Seems like something with the carburetor might be clogged but I dont know. You'll have to treat me like a complete novice because this is the first carb-anything I've ever owned. I've swapped motors, changed just about any part, transmission, etc on any car but it's all EFI. I honestly dont even understand how a carburetor works, but I'm trying. I've bought the repair manual online and read through the carburetor section but am kind of confused with it altogether. So after searching this forum, I cant seem to find anything similar to my symptoms. I notice there are some delicate brass items in the carburetor so I want to be sure of what I'm doing before I start breaking things.

So, based on my symptoms would the carburetor be a good place to start? If so, what might be a common problem with the unit?

Any help would be appreciated. Thanks a bunch.

Kevin

 

[Helmut]

Yeah, sounds like the idle circuit in the carb is stopped up. You need to take the carb off and take the bowl off and clean the jets and the passageways in the carb body. The jets are those brass things you spoke of. Also, clean the float valve and seat while you're in there.

 

[kcarel]

ok, got the bowl off, took the float out. Looking at the jets, it looks like I dont have a primary jet. What you see is how it looked when I took the bowl off. Is this wrong? What does the primary jet do and why would I not have this? See picture below.

I took the float valve out and I dont see any dirt on it. Not sure what I'm supposed to be looking for there.

you using just regular ole carb cleaner as your cleaning agent?

thanks a million.
Kevin

 

[kcarel]

here's a less blurry picture. As you can see, the initial jet is not there. This ATV ran for 23 years unopened so I doubt this missing part is the culprit in my current problem. But what do I know?

 

[Helmut]

I think that primary jet is just to help the ATV start easier. Yes, just use plain ole carb cleaner.

 

[dkmccreight]

LOVE the paper towels :happy:

 

[kcarel]

hahaha, I thought about that. I want to make sure everyone knows I'm not a representative of Brawny however, you may not reproduce, use or distribute the aforementioned photo without expressed written consent of Brawny, Inc. hahahah

Anyway, Hey! I got the damn thing to come on without straw feeding and it will idle without having to rev the throttle. I stripped it down per the book and per my new buddy helmut and ran compressed air through the holes/crevices and sprayed it down with gum out carb cleaner. put it back together and it will come on just fine. I will say, to kick start, I have to give it a little throttle to get going. I imagine I'm not kicking it hard enough to get it to come on without a little throttle assistance.

Only problem is my idle is kind of high. when I put it in gear, it bucks pretty good. I imagine thats because it's idling too high. I've tried adjusting using that black knob because I know that adjusts the throttle but I've backed that out as much as possible and I'm not noticing the idle going down. Any thoughts on what I should be doing for adjusting the idle?

Thanks!
Kevin

 

[Helmut]

Only problem is my idle is kind of high. when I put it in gear, it bucks pretty good. I imagine thats because it's idling too high. I've tried adjusting using that black knob because I know that adjusts the throttle but I've backed that out as much as possible and I'm not noticing the idle going down. Any thoughts on what I should be doing for adjusting the idle?

I would take that black plastic cover off the side of the carb and make sure the throttle drum is resting on the tip of the idle adjustment screw and make sure the adjustment screw is working properly. The cable might not be adjusted correctly and it might be holding the throttle open some. If that's not the problem, then your carb still has some debris in it somewhere. I know you didn't want to hear that last part, but sometimes you can't get the carb cleaned good the first time. It's easy to miss something and sometimes they can be a PITA to get perfectly clean.

Also, make sure the choke valve isn't sticking in the carb or the cable sticking.

 

[kcarel]

well folks, I'm a goofball. I was sitting there in the recliner watching the navy game and all of a sudden "oh crap I didnt tighten the hose clamp on the coupler from the motor to the carb!" I went out to the garage and sure enough the hose clamp was loose, letting in air thus giving me higher idle. I tightened it down and the bad boy idles like a dream. So, problem solved. Thank God I did not have to pull that carb out again. You're right helmut, that was not what I wanted to hear. I hit that carb with more than a half can of gum out and put 90psi through the crevices and port. I thought I had it whistle clean. Seems like it is. For a 23yr old ATV, I have to say this thing runs pretty dang solid. Not bad for $250. Signing out for now, but I'll be around lurking for new parts.

thanks!!
Kevin

 

[Helmut]

Glad you figured it out and didn't have to pull the carb again.