Question

[MudBug]

How to check valve timing on a Big Red 250

remove valve adjusting covers, rotor cap and timing hole cap. rotate the crankshaft clockwise and align the "T" mark in the rotor with the index mark. the piston must be at TDC on the compression stroke.

1.) How to I rotate the crankshaft?
I'm thinking with the kick starter?

2.) What is TDC and how do I know if the piston is at it?

[125Mule]

you can pop the plug out to tell where tdc is, use the kick start by hand.

[MonroeMike]

Have you checked the manual?

http://72.52.143.80/~trikes/Manuals/ATC%20manuals/atc250es-85-87servicemanual.pdf

[lndy650]

tdc is top dead center(piston reaches its highest point) the best way to rotate the engine is by the crank with a socket by taking out the plug on the side cover to expose the flywheel bolt. remember you have to be at tdc on the compression stroke to adjust the valves

[leevarnado]

yeah,cant go wrong by reading the manual.i usually turn the engine over with a socket and racket,works really well on some models but not sure on the 250es

[MudBug]

when I turn the engine so that the piston is at its highest point, the intake valve is not closed. do It mean it is not on the compression stroke, this is every time I get the piston at TDC. will this affect adjusting the valves?