1978 kz400 wont start! HELP PLEASE!!!!!!

Hello everyone! My name is Dylan i am 21 years old and live in Denver Colorado. I am new to this forum and also new to the mechanic aspect of motorcycles. this is my first bike and not sure on how to fix it but would like to do it myself. Ok here is my problem, once again my bike is a kz4oo 1978 and i have cleaned the carbs spotless, motor cranks and sparks but for some reason wont start up. we have had it running for a solid 45seconds and it died. only thing i can think of is a electrical problem because the low beams dont come on and nor does the neutral light. Im thinking that if the neutral light is not coming on this something is not triggering in motor? If anyone can help me here or has some input it would really help me out!

Welcome to KZR. Where are your pictures of the bike?? Thats always good to everyone interested in your project.
So do you have the service manual for the bike? You need the correct service manual to get you through the service and repair. Here on KZR we have "File Base" at the upper right hand corner of the page. You will find lots of good info there.
Did you also clean the Tank, or you will re-contaminate your clean carbs.
Now do you have the Air Box/ Filter hooked up? The carb needs this to work correctly or it will be lean. When you cleaned the carb, did you take out the jets, the pilot screw and blow it out with compressed air and carb cleaner? Did you set not just the dry float height, but also the Wet Fuel Level? This is done with a piece of clear tubing hooked to the drain. Search here for Clear Tube Test, and you will find the posts. Then when setting the Pilot Screw, how many turns out from lightly seated are you starting at? Make sure you have all the vacuum fittings either hooked up correctly or capped off so there is no leaks there. Make sure the bowl vents are open though.

First of all, you couldn't have gotten a better bike to start off with. these old kaws are easy to work on and will run forever, parts aren't too expensive either. When you go to start it and the engine is turning over, is the spark plug wet when you pull it? When you started it before for 45 seconds, did you use any kind of starter fluid?

Try shooting some starting fluid in the airbox before cranking and see if it tries to fire,this will give you a general direction to start in.
As far as the neutral light ,have you checkrd the bulbs?

Pictures of bike will be up real soon! yes i cleaned tank, i do nit have air filters on need new ones because i did not like the box, cleaned jets when cleaned carb, and as far s the rest of your check list MOTOR HEAD i have not done. KZCOOL i dont believe the sparks are wet when i pulled them before but i will check that again. WIREMAN i did try the starter fluid trick and it just back fired lol and no i have not checked the bulbs i will have to do that! but does anyone know if their is some sort of triggering system from neutral to the motor or something like that??? I am stuck on that thought so if someone knows please fill me in lol.

Thank you all so much for helping!!!

2wheeldeal wrote: ...i do nit have air filters on need new ones because i did not like the box....

why the sad face? help me out here?

(IF the bike has good compression) You gotta figure out if it fuel or electrical. i would test coils to make sure there putting out what there suppose to. if your getting good volts its prolly fuel/air related. Did the bike sit for a length of time? IS it modified exhaust,jets etc ? and you wont regret getting a manual

2wheeldeal wrote: why the sad face? help me out here?

You stated:

You have a 1978 K400. (So unless someone has replaced the carbs, it has CV (constant velocity) carbs.)
You have not only removed the airbox (not good with CV carbs), you have totally removed all air filtration (even worse, especially with CV carbs).

I believe whatever problems you are having trying to get the engine running well are compounded by what you have done regarding the air filter. Trying to diagnose and properly tune an engine that was already running poorly before removing the airbox/filters is going to keep you busy for a very long time and will very likely result in a lot of guesswork, trial, and error (not to mention frustration and wasted $$) now that you have removed the air filtration.

A much better approach would have been to get the engine running well before making modifications. Doing that would have allowed you to easily tune the bike properly to stock specs in order to set a performance baseline. Once that was done, you could measure or observe the effect of any mods to see if the mods made the engine run better, the same, or worse and then adjust as needed. By making mods to an engine that already runs poorly you cannot tell what effect the mods have on performance. Maybe they are contributing to the poor running (most likely) or maybe the poor running is caused by something totally unrelated.

You may want to do a search on this forum using the keywords "pods" and "CV". Also, if possible, you may want to reverse the changes you made and tuning the bike with stock components, get it running well, and then decide on and make mods if you want.
Ed

650ed wrote:

2wheeldeal wrote: why the sad face? help me out here?

You stated:

You have a 1978 K400. (So unless someone has replaced the carbs, it has CV (constant velocity) carbs.)
You have not only removed the airbox (not good with CV carbs), you have totally removed all air filtration (even worse, especially with CV carbs).

I believe whatever problems you are having trying to get the engine running well are compounded by what you have done regarding the air filter. Trying to diagnose and properly tune an engine that was already running poorly before removing the airbox/filters is going to keep you busy for a very long time and will very likely result in a lot of guesswork, trial, and error (not to mention frustration and wasted $$) now that you have removed the air filtration.

A much better approach would have been to get the engine running well before making modifications. Doing that would have allowed you to easily tune the bike properly to stock specs in order to set a performance baseline. Once that was done, you could measure or observe the effect of any mods to see if the mods made the engine run better, the same, or worse and then adjust as needed. By making mods to an engine that already runs poorly you cannot tell what effect the mods have on performance. Maybe they are contributing to the poor running (most likely) or maybe the poor running is caused by something totally unrelated.

You may want to do a search on this forum using the keywords "pods" and "CV". Also, if possible, you may want to reverse the changes you made and tuning the bike with stock components, get it running well, and then decide on and make mods if you want.
Ed

This really good advice, 650ed. It would be best to make sure the bike is running pretty good Before starting Mods. For street riding the Stock Airbox is by Far the best choice. IMO anyway. The Bike will run fine with the stock components or there is a problem that needs repaired.

I went to look at a Suzuki 550 a few months ago and the bike had the exact same symptoms. I had the owner try to start it while I put my hand loosely over the carb intakes. The bike started and ran because of the air restriction I put in place. He did not have the original airbox, because he did not like the look of it. He had tossed it. Put the box back on and get her tuned up and running right. Then as you make ONE change at a time, it is much easier to figure out why it is not working or what needs to be tuned. By the way, the engineers went to a lot of trouble to figure out how to get these things running well. If you do decide to change to aftermarket air pods or such, make sure you know how to do a proper plug chop.

Yes the bike has sat for a few years but in very good condition!