Can't figure why my bike quit running...

I recently completed a rebuild on my KZ 900. It has a 1075cc kit and .385 lift adjustable cams.

At first it ran pretty good. I managed to get the valve clearances set right and I was in the process of dialing in the 29mm smoothbores when on one test ride it just died.

It stopped so suddenly I figured it had to be an electrical problem and as I was pushing the bike back home I thought one of the wires from the fancy dyna ignition system had come loose.

No such luck. The ignition timing is still dead on and the spark plugs have good spark.

I did notice that the spark plugs seem to stay dry, even with the choke on and the throttle fully open while turning the engine over with the starter. So I took the carbs off and looked them over. Everything seems fine inside the carbs, and they are getting plenty of gas, so the only I can think of is that the valve timing must have gotten messed up.

So here's my question:

If the sprocket bolts were to loosen and allow the cam sprocket to move thereby causing the valve timing to go whacko, could the timing go so far off to cause the engine to stop running?

Any thoughts would be appreciated...

do not quote me on this, but with the timing off it should still try to run, but it wont be run good. Spray in some starting fluid and see if it starts. Or you could dip, the tips of the carbs in gas or pour a little into the cylinders. If it runs/fires you probably just arent getting gas.

Scoot Jockey wrote:

If the sprocket bolts were to loosen and allow the cam sprocket to move thereby causing the valve timing to go whacko, could the timing go so far off to cause the engine to stop running?...

yes.

I'd pull the spark plugs and look in the hole with a light as I turn the crankshaft slowly. You should be able to see the edge of the valve opening to make sure it's opening at the right time, and don't force it in case the cam timing is off you can bend the valves.

Scoot Jockey wrote:

...spark plugs seem to stay dry, even with the choke on and the throttle fully open while turning the engine over with the starter....

Nice avatar.

We don't need no stinking throttle fully open when choke is on. :lol:

"Choke" is actually a separate independent enrichener circuit inside the carb designed to function with the throttle left alone in the fully closed position.

Good Luck!

Thanks for your input everyone. I'll keep working on it into the weekend. I wasn't sure if the adjustable cams had the potential to mess the timing up enough to cause this problem. I'll know more in a couple of days (hopefully)...