I have a 2009 Polaris sportsman 400 H.O. when I go it I put it on a charger and found out the battery was don so I bought a new one and replaced it. B before I did this I started it off the charger it has jump start mode got it running and rode it around my yard to warm it up and make sure everything worked. When I replaced the battery in it. It cranked over but it didn't start right off had to choke and pump the throttle to get it to run.

could this be a fuel pump or timing issue ??

 

Does it crank and run ok now? If not could be a carb or possible fuel pump issue. Pull the fuel line from the carb and crank the engine over. Should be a steady stream of fuel if the pump is ok.Open the drain screw on the carb bowl. You have to crank the engine over a few times to let the bowl refill. If it's still hard to crank could be trash in the tank or carb jets. Plus if it's been sitting up for any length of time carbs can get gunked up. Jumping off a battery can cause some electrical damage if you're not careful. Check that when running that the battery is charging between 14-14.5 volts. If it just shows battery voltage you may have fried the regulator.

 

Yes it cranks and runs fine after it is started. I noticed when I was using the start mode on my charger it cranked faster than it does on the battery alone that is why I was asking about the timing. To see if it have a variable advance on it. So when I get home tonight I will pull the fuel line and see how well it pumps.
Thanks for the help. I will let you know how it turns out.


Thanks Scott

 

You just supplied more amperage to the battery using the start mode on the jumper. That's why it spun over faster. Not really a good idea on doing this from now on. If it cranks and runs ok now,battery is showing 14 volts+ while at an idle, wouldn't worry about it.

 

Ok then, It must be a demand of fuel issue then. And I did notice that when it was cranking it over, it was spitting fuel out of the air box side of the carb also

 

Simple things like when was the last time you serviced the atv,changed the plug,cleaned the air filter,replaced if needed,checked/adjusted valves? That could also have something to do with it spitting fuel also. Plus may be time for a carb clean along with a new needle and seat that comes in a good carb kit. Shindy Carb Repair Kit For Polaris Sportsman 400 03-05 03-413 | eBay

 

well I have only had the wheeler for a couple of weeks. as for the plug I just put a new one in the old one was carboned up as for the filter I took it out it looked fine to me as for the valves I haven't messed with those or taken it to the shop yet. the carb I am sure I can do that on my own. just have to get the kit for it.

 

The manual can save you some serious $ if you want to check the valves and do routine service.Very easy to check/adjust valves and the manual goes into good detail on this and other service/repair items.2009 Polaris Sportsman 400 H.O Service Manual PDF Download Piston at tdc and the cam sprocket alignment pin straight up,then you can check valves like this diagram from the manual shows.

 

ok here is what I have found out on my 400. the fuel system works fine, carb is clean and looks to have already been rebuilt. got to thinking about spark not knowing the machine that well and how it was used I was wondering if I could have a spark issue from the Stator pick up from rust possibly ??

 

Pull the plug and set it against the cylinder and crank the engine over. If it doen't have spark,then another good reason to get the cheap manual as it goes into detail on how to check for a no spark condition.No sense just guessing on what may be wrong.2009 Polaris Sportsman 400 H.O Service Manual PDF Download If it does have good spark but still doesn't run right, still a good reason to get the manual because it has other trouble shooting steps and checks to help eliminate the problem.