Hi. The timing is right on, is getting fuel, and has spark but wont start. It will back fire out the exhaust once in awhile. We were riding the past two weeks, bike ran fine. Came home put the bike away, Want to start it and it wont stat. Could it be the valves need to be adjusted. Bought the bike brand new and never adjusted the valves.
Thanks

Checking valve adjustment may be a good place to start after not checking them for almost 16 years. If they are at .006 intake and exhaust or even if you have to adjust them,if it still has a problem,could be fuel or carb related. You can pull the fuel line from the carb and crank the engine over. Should be a steady stream of fuel. If not,the fuel pump may need to be replaced. If it's getting fuel,may be time to go into the carb and clean and rebuild it.Polaris Sportsman 500 Carburetor Repair Kit Fits 2001-2002 Carb: Shindy 03-408 If it get deeper than this a service manual can help.http://polaris-atv.brssm.com/2002-Po...ce-Manual.html Plus don't over look the simple things like a fouled plug,dirty air filter,etc.

Hi. well the carb was just replaced in may, new spark plug just pun in getting good spark. I know im getting fuel to the plug because it is wet when i pull it out. like i said before it was running fine before i put it away, do you think the valves could cause it not to start all of a sudden.
thanks

Could be any number of reasons it won't start,tight valves could be among them. Check them off the list,pull the new plug and ground it against the engine to make sure it has spark. If it does and it's getting fuel to the carb,the carb would be the next logical thing to check. You can also see if tries to crank by shooting a little starting fluid in the air box and crank it over. It's lighter than gas and should suck it right into the combustion chamber.If it won't at least try to start on this,then that's where the manual comes into play on the trouble shooting steps and checks.

O.k Thanks, I guess have some work to do. I will start with the valves.
Thank Again