2005 Polaris Sportsman 500 HO Carb./Fuel Pump problems.

[JunkerG]

I have a problem with gas leaking out of the overflow tube on the carb when riding. I doesn't leak when the bike is just idling or if I rev it up while sitting still. The original carb had other problems to but could never get the float set correctly to stop the gas leak. I bought a new carb from China and it does the same thing, all adjustments were checked and changed if necessary. Giving up on that I bought a Mikuni carb off e-bay checked and installed it. Each of the carburetors were cleaned and O-rings replaced where needed. I didn't do anything to new carb except adjust pilot screw and float settings. Same problem. I found a post by  

 

2005 Polaris Sportsman 500 HO Fuel Pump

Started by Yoda, November 28, 2010

Talking about the fuel pump also controlling amount of fuel in carb. Does anyone think this could be my problem? How can I test this without fuel pressure gauge.

Thanks

Merry Christmas to all.

 

  

[Ajmboy]

It sounds to me like a float issue still and I would probably open the carb and check the float movement. Even though you say things were rebuilt, you may want to open it up and check movement. These carbs are prone to leakage and it usually is from the float not adjusting properly.

[JunkerG]

I know it sure sounds like a float issue but changed the float settings multiple times on each of the carbs.

Today I put a clear hose on the overflow pipe and watched where the gas level showed during running and driving condition. The level is where the book shows it is supposed to be. Because the tube I used was quite long I had made a circle out of the excess. After riding it awhile I noticed there were a few drops of gas up in the circles. 

I also found out that it doesn't matter much if the impulse line (vacuum) from carb is hooked up or not.

I failed to mention on first post that this unit is very hard to start. I have to hold my hand over carb to get it to fire, choke doesn't have any affect. When running if I pull the choke it will start missing or die, so it appears to be working.

[JunkerG]

I found one of the problems with carb I ordered off of e-bay. The brass tube that goes between the choke tube and the base of the carb is broken where it connects to the base. I did not clean the dirt off of that area before I installed the carb, I should have, I may have seen the tube had come loose. I was lucky I had taken the warranty from Assurant when I bought it. I got the full purchase price of the carb in the form of a e-card for e-bay. I was out the purchase price of the warranty $10.49. I still don't know why the choke don't work on the China carb. As far as the gas overflow, I ordered a fuel pump from China. I'll advise if that fixes the problem.

[Snowbound]

In my case, it was the o-ring that goes on the seat for the needle valve. I saw that you replaced the o-rings, but did you check this one as well?  Mine looked fine, but was just a little too loose.   Installed a new one and vent leaks all gone