1978 KZ650 Won't fire up

[CUBuffs]

I picked up a barn find recently, a KZ650 that must have sat for a long time. It was ugly and missing a few parts. I have cleaned and rebuilt the carbs both with carb cleaner and using ultrasonic cleaning. I installed new ignition coils (they were missing), new plug wires, caps and plugs. I have verified that the right side coil wires go to #1 & #4 and the left side goes to #2 & #3. Installed a new battery, changed the oil and filter, installed new throttle cables, new fuel lines. Also reset the gap on the points.

With gas in the carbs and using the starter button or the kick start the engine will not fire up. I have a 78 KZ 750 that I have to pull in the clutch in order to start so I have tried that as well on the 650.

What am I missing? Help is appreciated.

[CaptonZap]

Is the kill switch off? There has been a bunch of that going around.

Take the spark plugs out, leaving them hooked up, lay them on the head, and use the starter. If you see good thick blue sparks across the gaps, you can assume you have one of the cornerstones of combustion.
Stick you nose down by the sparkplug hole, or use a paper towel tube to put over the hole, and crank it again. Do you smell gas? There's the second.
Now it becomes a question of "is the spark happening at the right time". Did you try and swap the primary leads to the coils?
There are a jillion reasons that it won't start. We don't know what the PO did, or didn't do to it, or what you did or didn't do, so you are going to have to start on a "which" hunt.
(Which fault is keeping this thing from running)
See if you have spark, we'll go from there. It is the easiest thing to check, and almost the most important.

CZ

Check with HBonser, and see if he might be interested in coming by tomorrow and taking a look. He was looking for a ride destination, and Castle Rock is not that far.
I could swing by in the afternoon, I have a set of 650 carbs that need inspection in the AM.

[CUBuffs]

Thanks Zap, I do have spark on all plugs but not sure how strong. I believe I smell gas in the plug hole. I have not checked the timing since I don't have a timing light yet. I have checked the primary leads and they appear to be correct.

[CaptonZap]

Thanks Zap, I do have spark on all plugs but not sure how strong. I believe I smell gas in the plug hole. I have not checked the timing since I don't have a timing light yet. I have checked the primary leads and they appear to be correct.

If you are getting spark, that indicates that the ignition is working. What spark gap are you using? What point gap? Swap the primary leads to the coils and see if that helps.
Did you check compression on all cylinders? Should be above 100 psi, and all within 10 psi of each other.
Spark plugs clean? CZ

[CUBuffs]

Hey Captain, the points gap is .014 in. The plug gap is .030 in but I'm going to recheck them again as well as the compression.

[CUBuffs]

Bad News

I checked the compression (or lack of it). #1 cyl showed 40, #2 showed 0, #3 showed 90, #4 showed 50. I put a tsp of oil in each one and retested. #1 went to 90, #2 went to 60 then lost it completely, #3 went to 160, #4 went to 90.

Looks like I have some issues. How much time and money am I looking at to fix it?

[CaptonZap]

I checked the compression (or lack of it). #1 cyl showed 40, #2 showed 0, #3 showed 90, #4 showed 50. I put a tsp of oil in each one and retested. #1 went to 90, #2 went to 60 then lost it completely, #3 went to 160, #4 went to 90.

Looks like I have some issues. How much time and money am I looking at to fix it?

Well at the risk of sounding like a spoil sport, quit acting like newb, and figure that you don't have to ride it right away. And throwing money at it doesn't always fix things, although, if you have a lot of spare money, there are people who would be glad to charge you lots to do what you can do yourself.
Any machine that has not been exercised in a long while should be gone through and made right.
Have you set the valve clearance? Do it.
New plugs? Oh yeah, thats good.
You have all the ingrediants of a runner, all you have to do is get them co-ordinated.
Find out why the compression went away on #2. (Check valve clearance)
If you can watch the valves operate, turn the engine over by hand, and check that a valve on #2 isn't hanging up. (put #2 on TDC firing stroke, and tap the valves. They make a distinct sound when they hit the seat. Dribble some oil on the stems of there isn't a seal on them. Get a differential pressure checker, and do things right. )
You can run an engine with one low cylinder, and sometime it will come back up. The rings get stuck in the grooves, and loosen up with running. Some folks will put a quarter of a cup of Marvel Mystery Oil in each cylinder and let it soak for a day, then suck whats left out, and start it and try to think up a rational explanation to give to the fire department when the neighbors call them after seeing the clouds of smoke coming from your drive way.
But first, get it to run.
OK, let us know what's what with the valves.

CZ

[XJfan1]

I'm going to go out on a limb here. Are you getting any firing or backfiring. If your getting gas and spark you should have some signs of life. Maybe try a little starting fluid and see if she fires. Kawasaki made a semi rare bike for 2 years just in the 650 model. 78 and 79 were the only years. The sr650 had a coffin shaped tank. And the stock exaust was a little different. A sr would be a killer barn find.

[DAVINCI]

Have you set the timing? Had experience with those old Kawas, the timing is more than the points gap. Gap sets the dwell (how long the points remain closed in crankshaft degrees). The baseplate rotates to set the time the spark happens, just like on our XS's. You service manual will have the procedure, but here's a short version. You can also do this with a test light.

Connect a multimeter at the wire connector on the points, the other lead the the baseplate polarity does not matter.

With the multimeter set on OHMS (RX1) and the crank rotated to #1 (or #3) TDC the marks are visible through the hole in the plate, loosen the baseplate screws and rotate the plate so the meter just shows infinity. Rock the plate for a fine adjustment, you don't want the points wide open. Lock the plate screws down and rock the crank to and fro watching the timing mark and the points should just open as the mark lines up. Now your spark will happen at the right time.


Fire her up.