troubleshooting tips?

Hi,
I have a 75 KZ400S that won't start. The battery is charged, lights come on, and there is fuel in tank. I kick the kick start and get nothing.
Does anybody have a list of typical troubleshooting steps?
Please help a noobie.
Thanks

Do you have spark to the plugs? Pull one out and hook it to the wire and lay it on the engine so it will get a ground and try starting and you should see a spark jump across the electrode of the spark plug. Check that the kill switch is not in the off position.

Check for spark, pull a plug put the cap on it and lay it against the cylinder and kick it over should see a spark if not check your ignition coil per service manual

MAN I DONT TYPE FASST ENOUGH:laugh:

You have to pull the clutch lever in even when the bike's in neutral on some older Kaws -- I have a 1978 kz1000 and the thing won't spin the starter until the clutch is pulled in.

Yes do the spark plug-laying-atop-the-cylinder, and make sure the metal base of the plug is touching the metal of the cylinder head to get the grounding the plug needs, and as mentioned above the plug must be in the spark plug cap.

Is the spark plug damp/wet? If so it is fouled, let it dry a bit then try again.

If you cannot see spark on the plug, repost here for more help.

If you do get spark -- check for gas supply:
- is the tank low on fuel and if so, do you have the petcock on 'Res' (reserve)?

- if you put the petcock on 'Pri' (prime) is it only then that you see gas flowing out of the tank to the carbs? Maybe the vacuum-operated petcock diaphragm is busted and isn't letting gas flow to the carbs.

If it is getting spark,then you need to check compression also. Does it have fresh gas in it? Is it even trying to fire at all?

Not trying to be a wizeass but is the kill switch in run position? Just want to rule out the obvious, it is a newbie symptom.

Thanks everybody I'll try the spark plug first and let you know how it goes.

Hi,
Okay, I've got spark. The fuel valve is in the on position and the engine switch is set to run. Do I have to hold the throttle open while I turn the motor? Also, how do you clean the inside of the gas tank, its pretty rusty.
Thanks again

newOld_kz1000 wrote: "You have to pull the clutch lever in even when the bike's in neutral on some older Kaws -- I have a 1978 kz1000 and the thing won't spin the starter until the clutch is pulled in."

Not when using the kickstarter. If you pull in the clutch when kicking the engine will not turn over. Ed

gigolojoe wrote:

Hi,
Okay, I've got spark. The fuel valve is in the on position and the engine switch is set to run. Do I have to hold the throttle open while I turn the motor? Also, how do you clean the inside of the gas tank, its pretty rusty.
Thanks again

Do I have to hold the throttle open while I turn the motor? --- with choke applied for starting cold engine, don't touch the throttle when cranking over the engine.

Should have inline fuel filter(s) fitted to trap any grit or crud coming from inside fuel tank.

Also a good idea to remove the tank and flush it with a little fresh gas. Shake the tank with some fresh gas in it, and then turn it upside down to fast dump gas through the open cap.

Good Luck!

"how do you clean the inside of the gas tank, its pretty rusty."... Stop right there!

Have you been using this tank while trying to start this engine? Please say it isn't so....

If so :blink:, you have crap in your carbs now... 99.9% positive they will require cleaning... Remove a crab float bowel, rust particles/grit in it then yup, you'll need to clean them out thorughly....

Several products out there to clean the internal tanks such as Kreme... They'll clean & seal the tank...

As Patton mentioned, the in-line fuel filters, no doubt the only way to go... New clear fuel lines are a KZGod send for you can see what the hell is being delivered into your carbs and see if fuel is actually flowing...

Your petcock will also require some cleaning.... Possibly re-building with new gaskets...

Hi,
Thanks everybody for the help. Today I took the tank off and the carbs out of the bike. One of the fuel lines from the tank is clogged and one of the carburetor float bowls was full of a dry white chalky sand. Guess I need to do a rebuild of the carbs or replace them.
Thanks