2000 Polaris Trail Boss 325

It was running rough, hard starts, coughed on hard acceleration, etc.

I've done a lot to this Trail Boss, but never got into the carb. Was always afraid I'd mess that stuff up.

It now runs like a sewing machine. I also rechecked the valve clearance. I think I nailed that this time too.

I still have 2 problems, and they may be related:

1) Still hard to start. Once started, runs better than ever. If I take the air filter off and put my hand over the intake, it blows a little gas on my hand, but cranks up and runs great. I've adjusted the choke cable to spec, less than spec, greater than spec. No difference.

2) If I open the carb bowl screw, shouldn't it basically pour or fast drip gas out of the small hose? The hose isn't blocked, and the bowl is for sure clean. I didn't check any incoming (to the carb) hoses, as I assumed their large diameter would be ok even with some small blockage. I even tried sucking fuel from the hose, but just got fumes.

Are these two problems related?

I did run the atv wide open on the road for a good distance (I still don't think it has the top end speed when new, but it takes off like a scalded dog). So, it isn't starving for fuel at all.

I'm stumped.

Larry *

 

Did not figure it would be so difficult to get an answer on at least #2 question.

*sigh*

Larry

 

Been a while since I touched a carb but it sounds like you may have a float or jetting issue. There should be a line on the outside of the float bowl showing proper height of fuel in it. I used to check the height by attaching a clear hose to the nub where that drain screw is and hold it vertical with the carb while running. Gravity will push fuel in that hose to the height in the float bowl. If it's off then you can bend the tangs to adjust the level. Could also be jetting off or your carb may just need to be rebuilt. Seals dry out over time and don't get fuel through the carb like they should. If it's starting hard cold it wouldn't hurt to double check valve clearance again.

 

Thanks. I don't think I have any fuel in the bowl at all. The hose is clear, and opening the drain screw let's no fuel out.

Is it possible for it to even run with no fuel in the bowl? It must be, since I can eventually get it started and then it runs fine.

So, what is the most likely blocked hose bringing fuel to the bowl, since there are several sections?

PS: I just rebuilt the carb. No new parts, as they were all in good shape, but gave it a good cleaning.

 

Going to have to check section by section if that's the case. If there's no gas in the bowl then you may have accidentally bent it while apart or the float itself could be bad. Best bet is to check the fuel lines first starting from the tank. Not too familiar with your machine. If it has a removable fuel petcock start there. Could be some gunk restricting flow. If everything flows good from the tank to the carb then you can start troubleshooting the carb.

 

Thanks!

The float should be fine. It is possible that I bent the tab, but I was so careful, I'd be surprised if I did.

Everything is so dadburn hard to get to, I'm dreading getting back into it.

Larry

 

It sure sounds like your fuel supply to the carb is being restricted. Take the fuel supply line off the carb, fuel should run freely out of the hose coming from your tank. If not, you have found your problem. Good luck