Pile of Crap

All I can say is my username says it all. The stupid bike has spurts of running really well, giving me hope, then suddenly it dies and will not run.

I had the bike running, letting it warm up. I put in a brand new battery and it was running so well. Suddenly I heard this hiss, like a "psst", really quick, and the rpms dropped and it died. I tried to start it again, and it would crank then make that "psst", and stop cranking. I tried it for awhile, 5 or 6 times, then suddenly the battery just gave out. It gave one last crank "psst" and the battery was dead.

I'm ready to take it to the shop and lose my tax return on it, or just take it to the shop and leave it.

Check fuses?

Hang in there....and don't take it to the shop cause it will just cost you an arm and a leg and you may never get to know what was wrong. Remember the few things needed to make an engine run...spark at the right time...fuel...compression. Get those sorted out one by one and you will be OK. Just need to learn about it yourself (as I am doing too) because when it does go wrong again you (I) want to be able to fix it. As I don't know a huge amount I will just throw some ideas out there...If the battery you put in was new and it failed so soon then it sounds like an electrical drain issue and/or poor connections...the pssst sound is probably air escaping from somewhere - check head gasket. This apart from all the usual checks - valve gaps, carbs clean etc. I am sure more knowledgeable people will have more exacting things to say...but don't give up!

See if any of the vacuum caps have popped off on the intake manifolds.

I followed the wiring diagram found in the filebase for the fuses, just to check off the ones that needed replacing (if any). None of the fuses were blown. I did find, however, that a lot of the wire colors were wrong when compared to the diagram. I used the KZ750R1 diagram, my bike is a GPz750. Please correct me if I'm wrong, but aren't those the same?

Also, I discovered my seat is a KZ700 seat with a KZ700A owners manual under it. Probably just a seat swap, but with the wire colors and the seat I'm beginning to wonder.. Is this bike REALLY a GPz750? The engine code says KZ750EE..

Either way, I still have no idea what's wrong. I have fuel, I have spark.. I need to check compression. I just want to get this electrical issue out of the way first so that the bike doesn't have to be hooked up to jumper cables while testing it.

If it stops cranking after making that hissing sound then I would say it is an electrical problem. Check all your electrical connections from the starter button down to the starter sylenoid. Make sure you also check the clutch safety and kickstand safety.

I'm with loudhvx. I'll bet some vacuum hose or cap has come loose. check the vacuum cap on each of the four carbs. Also check the vacuum hose that goes to the fuel petcock. Usually connected to carb #2.

Just my wild guess.

Hang on to that GPz. They are not the ordinary KZ.

It was a vacuum leak. From the fuel petcock to Carb #2. Odd thing is, I've taken off the tank before and never ever seen that line connected. I guess that why it used to idle like crap.

I had this same problem on my VW a few months ago. Vacuums on air cooled engines... they're all pretty similar. *sigh* when will I learn. Hopefully the battery actually holds a charge this time so I can finally get it registered

Without the vacuum hose connected to the petcock, the petcock shuts off the fuel supply. This is by design for safety reasons. So when the hose came off, you were both drawing in excessive air, and the fuel should have been shut off. No wonder it quit running.

Indeed. I feel bad for calling my bike a pile of crap.

There's still an electrical drain somewhere though.. Pressing the starter button kills the battery, so I've resorted to push starting it every time I want to ride. Possibly a short between the starter and the battery?

freakinbike wrote: Vacuums on air cooled engines... they're all pretty similar. *sigh* when will I learn

you should rue the day you wrote this. think of 4 individual lawnmower engines, then link them together on the crankshaft, then find the individual vacuum leaks are ruining your other cylinders. :evil:

Check and clean all your ground wires with DeoxIT D5 "red"
and all the other connections for that matter

www.mcmelectronics.com/product/CAIG-LABORATORIES-D5S-6-/200-040