1983 GPz550/KZ550 won't start and I'm flummoxed!

Hey fellas,

Many of you were recently instrumental in helping me rebuild the top end on my "nice" 1983 GPz550...and she's running great. That said, during the course of the rebuild, I acquired a parts bike - it had been in a wreck, partially dismantled, and left outside for untold years.

Well since I've got my primary ride up and running, I wanted tackle getting this parts bike running, partially so I can list it as a running bike and partially as a way to challenge myself to see if I could resurrect this ole beastie.



When it was laid down, the pickup coils, cover, and part of the engine case were destroyed. Since it was a non-load part of case, I used JB Weld to rebuild the missing section, sourced a new advance mechanism, and pickup coils.


The pickup coils needed some work as well and I cleaned them up and they tested good (I forget the readings now, but they were well within spec)


Additionally, the carbs were in awful shape. I've seen some bad carbs before, but these were awful. I used the (original recipe) Pinesol soak method with an aquarium pump and heater to warm the solution and circulate it.


Post soak - they cleaned up surprisingly well

I should also mention, before all this effort, I did a compression test, just to make sure I wasn't wasting my time.

Cylinder #1: 170
Cylinder #2: 95
Cylinder #3: 110
Cylinder #4: 150

Not great numbers, especially on #2, but I figured that there may be a stuck ring and expect some improvement after a couple of heat cycles; regardless, these numbers should be enough to get it running.

I then performed the requisite oil change. The old oil actually looked very good. Not milky or otherwise of note. No grit, etc. New oil went in.

After this I put everything together, installed the battery, and I do have spark at all four plugs. I have also cut off the last 1/4'' of the plug wires to ensure good connection. Spark is nice and blue.

So far so good, I rebuilt and then installed the carburetors (new o-rings/gaskets & no leaks/cracks in the diaphragms).

I also visually balanced the butterflies on the carbs after the rebuild and they are quite close...close enough that once running I should be able to balance them properly.

I rigged up my auxiliary tank, primed them with fuel and thumbed the starter. Crank is strong, but no joy. The engine simply will not start. I have gotten a *few* coughs and backfires over the past few days and have realized that I forgot to plug the vacuum nozzles. I was sure that I'd get it running after that, but still nothing. I've gone over everything I can think of, so at this point I'm need to call in some additional help.

I've checked and double checked the coils, spark plug lead routing, and have even ensured they were connected properly



I also checked the timing - when #4 is at the "F" mark, the advance mechanism is pointing the correct pickup coil


So the last thing, that I am unsure on and struggling to find any type of literature on kzrider or elsewhere on the internet is how far the butterfly valves should be open when the bike is at idle. I've see some bikes where there is a small gap, and some where it's closed because of a different circuit (which I THINK these bikes actually have, so I THINK these butterflies should be completely closed...right?)

Anyway, I've been playing with it all week, but here is the current setting on the butterflies, I can close them all the way, if that's the correct position.


Alright fellas...I'm pretty stumped. It won't even start when I spray starter fluid in the intakes...so anyone have any advice? I feel like I've pretty much crossed my t's and dotted my i's...

Thanks so much!

-Matt

Could the spark timing be 180* out of phase?

Nessism wrote: Could the spark timing be 180* out of phase?

So, I thought about that, and truth be told, I don't know how to check that to be certain, so I'd have to look that up unless one of you can explain the process.

BUT, the reason I kind of doubt that it is out of phase is because 1) I haven't removed the coils on this bike, and 2) the old wires have a set bend in them from age, so it's pretty clear which wire goes to which plug. I did replace the #4 wire with some scrap wire I had left over from changing out the wires on my Jeep, but the other three cylinders still have the OEM cylinder labels in place.

I suppose the doesn't negate the possibility, but if I were a betting man, and by the state of this bike, I assume this thing was abandoned after the accident by whomever was piloting it and that it was presumably in running condition at that time. It also doesn't appear that this engine has ever been cracked open, so I'm also assuming the cam timing is still in the factory settings.

Obviously I am a betting man because that is a lot of assumptions...:dry:

When the engine is on 1/4 tdc which way is the rotor pointing ?

One thing that gets overlooked a lot is the enricher jet in the float bowls, if it's blocked you can't start the bike without a long fight, I know this from experience.

Nessism wrote: When the engine is on 1/4 tdc which way is the rotor pointing ?[/quote

In this photo I have it aligned with the "F" and the rotor is pointing directly at the pickup coil. If I were to put it at TDC, the rotor would be pointing just before the pickup coil.

kevski wrote: One thing that gets overlooked a lot is the enricher jet in the float bowls, if it's blocked you can't start the bike without a long fight, I know this from experience.

I had the carbs entirely apart and was quite thorough, but which jet in particular are you referring to? I'm thinking I may need to pull these carbs and go back through them just as a triple check. I couldn't find anything on the diagram referring to the enricher jet though.

The jet i mean is the one in the float bowl where the brass lift tube goes down, it's pressed in and cannot be removed, if the bike has stood a long time and the fuel has evaporated these block up and can be hard to clear, if you fill up the large part of bowl and it rises up this hole it's ok, if not the jet is blocked, this may not be the same as your carbs but it will have the same sort of thing down in the encircled hole.

kevski wrote: The jet i mean is the one in the float bowl where the brass lift tube goes down, it's pressed in and cannot be removed, if the bike has stood a long time and the fuel has evaporated these block up and can be hard to clear, if you fill up the large part of bowl and it rises up this hole it's ok, if not the jet is blocked, this may not be the same as your carbs but it will have the same sort of thing down in the encircled hole.

Ah, ok, yes. I was sure to clean these ports as well. I went through the damn things very carefully with carb cleaning wires and air...but I'm just starting to think it has to be a fueling issue. I am certain that I have 3 of the 4 components needed; Air, Compression, Spark, and Fuel....fuel is the only one that I can't be certain of. The plugs are dry even after repeat cranking...so maybe something is still clogged?

I didn't see you mention doing a "clear tube" float level test ...

You have to separate the carbs for a better cleaning result. Never put brass,steel and aluminum together in a chemical dip!!!
Have you look under this plugs? Maybe some uncleaned jets. I could be wrong but i have to read something about this plugs/jets..



This is my kind of carb cleaning chemicals, i have best results with it.