Originally Posted by jcmmcote
I am rebuilding my 305 and the timing is killing me. I have the #1 piston up on the compression stroke. The dots on crank (up) and cam (down) are lined up. rotor button is facing the #1 spark plug and then I started my firing order. When I try to start it up, it blows out the carb like its 180 deg. out on the timing. I bumped the motor till I got the #1 on compression stroke again and the dots changed crank (up) and the cam (up). WHY????????
please if anyone has the answer I need it bad. Been dealing with this problem for about 4 weeks now. Thanks
Actually when the dot on the crank is in the up position and the cam sprocket is in the down position the #6 piston
is at TDC.
You have the distributor 180 degrees out.
When you bump the engine over and see the dots no longer lined up that is because this is when the #1 piston is ready to fire.
Lining the dots up is for the cam installation not for setting the distributor.
I'm not sure that I have explained this clearly. Try this.
Remove the #1 sparkplug. Disable the ignition so that the engine will not start. Place you finger (or a piece of tissue paper) over the #1 spark plug hole. Bump the engine over slowly until the paper blows out or your finger gets pushed away because of the engine compression. Stop at this point. Look at the timing pointer and timing mark. They should be very close to being lined up. Now re-install the distributor so that the rotor is pointing to the post on the cap where the #1 spark plug wire is located. Replace the sparkplug. Enable the ignition. Start the engine and set the timing with a good timing light. Be sure to dis-connect and plug the vacuum advance hose when setting the timing. Re-connect it after the timing has been set.