'81 KZ650 timing/starting trouble

Hey all, I'm new to the site. I'm fairly mechanically inclined, and I picked up my '81 kz650 with a box of almost all the accessories on the side. After a few hours installing the wiring harness and all the related components, I'm having trouble starting the engine.

We opened up the carbs and cleaned them all out. They were recently done by the previous owner, but I wanted to be sure. When turning the motor over, the engine will fire out of the carb intakes (all of them, at various times), and occasionally it will backfire through the exhaust.

We thought it might be a timing issue, so we were looking at the timing advancer. My friend pulled out the little orb thing that controls the timing for the coils, and now I have no idea which way to put it back in. Any suggestions on how to determine the direction would be phenomenal.

Also, any recommendations on why it might be shooting out of the intake would also be helpful. We thought it might be either timing or a valve that needs adjusting, but your brains are far more intelligent than ours on this topic.

Thanks in advance!

welcome,, I think you might have to coils reversed, since you said you installed the wiring harness on the bike it could be very easy to cross the 2 leads going to the coils

Well, switching the orb on the timing advencer would do the same thing, telling the ignitor where to send a signal. Before messing with the timing advancer, we switched the coil leads around and it didn't fire at all.

I'm researching and finding horror stories all over of engines that are torn apart. I'm wondering if I should pull the valve covers off and see if the cams look ok. Any thoughts would be greatly appreciated.

there is nothing wrong with pulling the valve cover and checking the clearance, and make sure the top end is clean, also when you put it back together put some oil on everything before you put the valve cover back on

Just in case...

The cylinders, spark plugs, etc are numbered 1-2-3-4 left-to-right as yer sitting on the bike. The firing order is 1-2-4-3.
The #1 & #4 spark plug wires should be connected to the right side coil which should have the black wire from the igniter.
The #2 & #3 spark plug wires should be connected to the left side coil which should have the green wire from the igniter.

There should be a notch in the advancer that fits a pin in the end of the crankshaft.

Be sure to have a good & properly charged battery.

Here's a link to an 81 KZ650-H1 CSR wiring diagram - reply #10.
I added info on the coils to make it easier to read.

TriniTT wrote:

...pulled out the little orb thing that controls the timing for the coils, and now I have no idea which way to put it back in. Any suggestions on how to determine the direction would be phenomenal....

Under the ignition cover ---

The timing rotor has one projection.

There are two pick-up coils, being one on the left-hand side (the "rear" or "aft" pick-up coil) and the other being on the right-hand side (the "front" or "forward" pick-up coil).

The advancer has 1/4 marks and 2/3 marks situated 180 degrees apart.

The projection on the timing rotor is supposed to point toward the left-hand pick-up coil when the 1/4 advancer marks are situated at the top.

Good Luck!

Thanks guys, that's all been helpful but unfortunately that's how everything was set up already. We just ran a compression test, and we're getting no more than 10-15psi on any cylinder.

At this point, we're thinking the cams are out of sync. We're going to pull the valve covers and check it. Can anyone link me to a pic or page that would have the info about how to set the timing chain?

Thanks for all your help!

We have the valve cover off, and I'm searching everywhere for a diagram for how to set or check the timing chain. I'm reading that there are supposed to be arrows, but we see no such arrows. Help is desperately needed...

Sorry for the continual bumps, but we just checked the timing and it appears to be correct based upon the strokes. However, we counted the pins between the marks and there are actually 38 pins, whereas I read there should be 36. Which is correct? The bike is an '81 h1.

Nobody can tell me how many pins are supposed to be between the cam marks for this particular year engine?

36 is the correct number. not many on here today because of the holliday weekend. be patient