kz 550 pissing me off. really weird things ,heelp!

I think is Not possible make a mistake during timing operation.
T mark alligned with the case
Pull the chain
Install exhaust cam with the ex line mark on the edge of the head.
Pull the chain, install the inlet CAM with the z/5 in mark line with the edge of the head.
Jnstall the cover and only AFTER the cover, installato the tensioner.
All OK, from first to 44th chain pin as manual says.
I have noticed that the z5 mark is IMPOSSIBLE to line up perfectly with the edge of the head until you install the cover. It is 1mm or 1,5 mm under the edge of the head until you install the cover.
Im totally desteoyed about this damn thing.
Huhu.
And i have to say i know well engines, i worked on alot of really negletted bikes with alot of problems but this time i cant figure it out, friends

rrsmsw9999 wrote: Can you get a video of wiring and an attempted start run up to UTube?

In the next days i will do that ASAP. i have the carburetors off again,tocheck and recheck..for the million+1 times

1982 Kz550H1 Gpz. Tk26CV carbs.
No hurry, but when you get a chance, put the bike year and model in your signature so everyone can be on the same page without having to look back.

So by the temperature, it seems 1 and 2 are the problem ones. Are they also the ones that go to zero vacuum?
What vacuum sync device are you using? Does it quickly pulse to zero, or does it stay at zero fro a few firings?

They are on different coils and use different ignition circuits. If the ignition module, or pickups, or coils were bad, you would see 2 and 3 fail, or 1 and 4 fail. But it could still be a plug wire or two jumping sparks.

I suppose a spark jumping to another cylinder, or an extra spark on a cylinder (sometimes the igniter is sensitive and will get extra sparks on a cylinder) could cause a backfire which could force a vac gauge to zero briefly. But it wouldn't sustain zero.

Do you have a timing light? You can use that to find extra sparks. You point it at the advancer, per the manual, and you will see a ghost image of the spark advancer in the wrong position.

I understand the frustration. Been there. Take a break. This is not a impossible situation and it can be figured out. Yours is not haunted or magically fukd up. There is something that not assembled correctly or not working correctly. These motors are bulletproof, but complicated and even the best make mistakes. U said this was the same problem as before, how did that first problem come about? R

Since i bought this bike the idle was ever crap. I use a simple carbtune Morgan, but it works..or at least it work on all other bikes i use it
During vacuum sync, magically one or more elements stop moving. Just drop to zero, even if the engine is still running. Grrrr... I cant understand.
Then, i hit the gas and suddenly, all 4 cylinders up to 25cmhg
I know maybe its a stupid thing, but im really with no more ideas...
I have a timing light, dont recall what brand is but i use it often and it work.
On this gpz i used it only one times, since the advance is Not adjustable, and i remember i saw the F mark aligned at "idle" (500-1600rpm) + or -..

Just stabbing in the dark here. Could something be partially blocking the fuel flow to carbs 1 and 2?
When the bike sits for a while, fuel slowly fills the bowls, but when the engine is started, those two run dry faster than fuel runs into them. That would not account for the jacked up vacuum readings, but that could have an unrelated cause.

shamal wrote: T mark alligned with the case
Pull the chain
Install exhaust cam with the ex line mark on the edge of the head.
Pull the chain, install the inlet CAM with the z/5 in mark line with the edge of the head.
Jnstall the cover and only AFTER the cover, installato the tensioner.
All OK, from first to 44th chain pin as manual says.
I have noticed that the z5 mark is IMPOSSIBLE to line up perfectly with the edge of the head until you install the cover. It is 1mm or 1,5 mm under the edge of the head until you install the cover.

Sounds like you have the cam timing correct. Z/5 doesn't need to line up as long as you have the tooth count correct.
You probably saw this already, but it has beeter images of the timing marks etc.
gpzweb.s3-website-us-east-1.amazonaws.co...KZZXZR550500400.html

Shot in the dark here - I also own a Morgan carb tune and it did not work worth a damn on the 550. I think the plug doesn't sit low enough in the cylinder to ignite. When I used it, to even get it to ignite I had the pilot screw adjusted so far off base it was crazy. I once tuned them all with the Morgan and out my plugs in and it barely ran. Put the screws back stock and it was fine...


Wait....I meant a Morgan colortune...I think the carb tune is vac gauges right?

Sticking valves, one sticks open, vacuum goes to near zero, because it can't pump air anymore. You rev it and the valve(s) unstick. Possible buckets also sticking.

I wonder how a sticking bucket can be more powerful thank a valve spring..and, the engine should have damage caused by pistons hitting the sticky valves. I think this is Not the cause, valves lapped, new valves seals.. Fresh oil everywhere..

All is smooth, and when the engine start to work properly, or when i rev it, it responds fine.

Any ideas about ignition system faults?

Don't look then, but this can happen. How else do you explain the random loss of pumping?

I was thinking about some internal carburetors problems. Two things i forgot to say are:
She drink alot of gas while the sync operation. I had to refill the 60ml siringe i mounted in the fuel hose someting Like 3 times in 2 mjnutes. And when i refill it i have alot of air Bubbles until the level become stabile again in the siringe.
And the brass mix screw are TOTALLY ineffective on each cylinders, even when the engine seems to running good. In any conditions.
May i have a leak on the brass vacuum ports mounted in the venturi? Hum..
Im considering to buy a "new" rack OK carburetors, since mine have been badly abused through the years... Is for sure the worst Part OK the bike.
Anyone know if Ivan try TEC aw82 (gpz 900r) instead of mine zc006 coils?