I am looking for suggestions why my sons 2005 polaris 250 trailblazer rev's up when started. The bike rev's up high enough that you cant take it from neutral to drive because it grinds. Any suggestions would be appreciated. Thanks in advancefor any responses.

Thanks
Dneuhof

 

Welcome to the forum! First thing that comes to mind is you probably have an air leak either in the crank seals,base gasket,cracked intake manifold,etc that's causing it to run lean. If it's seals usually the one behind the clutch goes out first. Plus you might check the carb slide and throttle cable for any sticking,could do basically the same type thing. OPT

 

welcome to the forum. agreed that it being a 2 stroke that you have a pretty good air leak, meaning it's sucking in air say around the carb boot or maybe the crank seal. it stays this way to long and it will run hotter cauisng the engine to melt down.

 

Thank you both for you quick diagram on the Rev issue with the 250 scambler. Now is there a way to check or test to pinpoint the air leak? Thanks again

 

Best way is with a leak down tester and soapy water,but you'd need an exhaust block plug and carb intake adapter with a low pressure gauge(7psi and must hold this). Just check the carb slide first for sticking(dirt/varnish on slide) and any visible cracks in the intake manifold. If this is ok, then I would pull the front clutch and replace the crank seal. Usually you can see an oil film around this seal or it could be partially popped out,sucking air. Plus you have to pull the flywheel and stator to replace the other seal. OPT