GL1000 ignition timing

[mikenixon]

Yeah, I know. Everyone has posted about this already. Here's my version.

1-After carefully adjusting the cam belts so there is minimal tension change as the crankshaft is rotated, remove and service the points assembly. This means dressing the two points assemblies and cleaning them with contact cleaner and a clean piece of paper, then checking the wires for fraying, grounding, and for tightness at their itty-bitty mounting screws.

2-Inspect the advancer assembly. Honda advancers rarely wear much, but it needs to be springy, not floppy or jammed.

3-Put a dab of grease on the point cam, the non-round part that rotates with the crankshaft and makes the points open and close. Then reinstall the points assembly.

4-Use an offset 12mm box wrench at the back of the engine to rotate the crankshaft clockwise until the left side points are fully open. You can turn the crankshaft back and forth to determine when the points are farthest open. At this position, gap the points to anything between 0.012" and 0.016" using a feeler gauge. The screw holding the points onto the main plate is loosened and the points assembly nudged more open or more closed to adjust the gap. Get it close, snug the screw, recheck the gap with the feeler gauge. When done rotate the crankshaft some more until the right side points are fully open. Use the same procedure and the same feeler gauge. All we've done so far is point gap.

5-Now find a 12v light bulb and socket. I like to use an instrument (speedo) lighting bulb and its socket. Put an alligator clip on each of its socket wires or solder wires and clips to the bulb if you don't have the socket.

6-Clip the bulb to the left side points and a good ground.

7-Remove all the spark plug wires so the engine doesn't accidentally start on you while rotating the crankshaft.

8-Turn the key switch on and rotate the crankshaft clockwise while watching the left side points close and keep turning slowly until they open again, while watching the timing window. When the F mark lines up with the index mark on the crankcase, your timing light should light.

9-If the timing is off, loosen the big Phillips screws holding the points plate to the engine and barely nudge the whole big plate and all its goodies clockwise or counterclockwise to correct the timing. Moderately tighten the screws down and recheck the timing.

10-Recheck the points gap with the feeler gauge. If still in the 0.012"-0.016" range move on. If outside, you have to regap. If regapping is needed, recheck the timing again.

11-Now let's deal with "ghost" timing. We're still on the left side points. Without changing anything, rotate the crankshaft 360 degrees until these points close and eventually open again. Only this time they will open on a different section of the point cam. See if the F mark in the timing window is at the same place as before. Usually it isn't. You didn't change anything, but the system threw a curve at you. See my articles on why.

12-Your job now is to split the difference between the timing produced by this section of the point cam and the earlier, opposite part of the cam. Use the big Phillips screws and the main points plate's position to do this. If you get the ghost within 1/8" you'll be doing good. There's nothing to be gained by getting it closer, assuming you even could. You'll want to recheck gap again afterward. Many folks get frustrated right here: all this back and forth, repeating the same adjustments. Nature of the beast. To make it easier on yourself, be relaxed about the points gap. Prioritize timing, which is far more important, and do the best you can with point gap.

13-Once you get the left points timed and gapped, move your timing test light to the right side points and repeat everything you did on the left side points, on the right side points. The only difference is on these points the timing is adjusted using the sub-plate (the small plate between the points and the main plate) to adjust the timing, not the main plate. If you accidentally use the main plate you will inadvertantly change the left side timing you so painstakingly set earlier, and you'll have to start all over.

14-The process is gap, timing, regap, retime. Pros do it in two to three minutes, with only one back and forth cycle. Beginners might take an hour and have to endure five or more back and forth cycles. Or it might take you half the day. That's okay. No sweat. Just do it.

15-If done correctly, this "static" ignition timing method is quite accurate. Dynamic timing on this bike doesn't come close to being as good. Don't forget however to manually check the spring-loaded ignition advancer by turning it with your fingers and observing it snap back. Also while the crankshaft mark is at the full-advance marks, twist the advancer to confirm proper full advance timing with your tiny timing light.

[rcmatt007]

always helpful, as my Ltd still has points....

I had forgotten how to do this as back in 1979 I put a Prestolite on my '78.... no regrets!

[mikenixon]