I am having trouble getting the timing set on my rebuild.If I use the timing marks it wont idle without turning up the idle speed on the carb which in turn opens the throttle enough to activeate the ported vacuum outlet advancing the timing when the vacuum hose is reattached.If I advance the timing to 55 BTDC it will run fairly good but still not right.I would like to figure out as close as possible how far out the damper is.I have a tape which shows lots of timing marks,If I knew how far out the damper is I could compensate when using the timing light.If I had known the damper was innacurate I would have replced it before assembling the motor.

  

Are you off one wire position on the cap?  55° is one place plus 10°

 
 Steve Metzger       Tucson, Arizona

The easiest way to set the timing without using timing marks is to connect a vacuum gauge to a manifold vacuum source. With the engine running turn the distributor until you get the highest vacuum reading and then turn the distributor back in the other direction to a point giving you one inch of lower vacuum.

Plug off the vacuum line whilst doing this setting.

Reconnect the distributor line.

This method works on any petrol driven engine.

You can retard the ignition a little if it pings when you get it on the road.

I always put a notch on the crank pulley with a triangular file when I first set the engine up and use this as a timing mark as I have had no luck with the damper ring being in the right place.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Hello Steve! I am wired correctly.I just have a feeling the damper is off.I am going to try and get #1 on TDC using cylinder compression tommorow and hopefully figure out how far off it is.Exact TDC would have both valves closed with the intake just starting to open I believe.Steve I had a question on my earlier post regarding the charging system.My battery wont take a full chargeOnly goes to fair on the hygrometer.I will replace the battery.Meanwhile the voltmeter is charging at 15-16 volts and goes higher as the revs increase.Is the bad battery causing this or is there a problem with the regulator maybe?Sitting all winter maybe did the regulator in?Rick,I have used that system myself. Before I rebuilt this one I used a gauge bcause timing didn't seem right.When I tore it down you could ALMOST lift the chain off the gears.That might explain the timing marks being off.

  

Both valves are closed for some time. Only a very small fraction of that time is the piston at tdc. You'll need to use a stop that threads into the plug hole in order to find exact tdc. With the stop in place, you turn the engine over by hand until it stops, mark the damper, turn the engine by hand the other way until it stops, mark it. Tdc is exactly in the middle of the shortest distance between those two marks.


Lawrenceville, GA

Your balancer has 3 spokes on it. One of the spokes when marked in the center is 12 degrees BTDC. Put a small white dot on the balancer where the center of the wide spoke should be and you may have to do all three to get the correct one. When setting the timing be sure to unplug the vacuum port. At this point you should be good to go.

-Gary Burnette-

I took a broken spark plug, welded in a male hoseline fitting, and attach some clear plastic hose.  screw in the base and put the hose in water.  When it stops bubbling and judt starts to suck in water, you're at TDC.  No bubbles, valves still open.

RB