hi im new to this , but i have gotten alot of help by researching things in this forum , so i would like to say thanks. but i have a question , is it possible to test compression on a polaris 400 engine with the reeds and carb off and be accurate?

 

Ideally on a car engine, you would hold the throttle in the full open position and crank it over 5/6 times to get a good reading.

With the conditions you describe, no restrictions, my thought would that would be an accurate way of doing it. Don't have a definitive answer.

 

Yes with reed block and carbs off compression test is ok,because no loss through intake unless rings/pison wear. Compression should be min 100 psi min,if less save $ for top end, also if you have access to leakdown tester check for crankseal leakage (Should hold 7psi with no seepage) If topend is going to be done MAKE SURE no play in rod (up and down) side to side play normal It maybe just ME,but I dont GUARANTEE just top end on older machines,because if bottom end goes out the brand new top end and $ will go with it usually! Will bore customers cylinders if doing own wrenching,but advise them. Just been snakebit on topends only in the past. Good luck!

 

thanks for the help. yes im gonna have to do at least a top end. planning on giving ritter a call