85 GPz 750 Cafe Project

Started with an 85 GPz 750 purchased from the original owner. Sat for nearly 15 years since he moved to CO from CA. Picked it up as a builder for a buddy who commissioned me to build his bike. Blew it apart, every nut and bolt. Shaved the frame, put a hoop on the rear, 77 KZ650 model B tank, 79 SR front fender that I shortened. Full carb rebuild, ultrasonic cleaned, Z1E kits, set the float levels. Shimmed the valves. Rebuilt the calipers and front master cylinder. Everything is back together except the headlight, front/rear running lights, turn signals, and wiring of the instruments. I tried to start her today on the baby bottle, no joy. Turns over nicely, spark at every plug tested with a color tune tool. My sense is something is amiss in the wiring. I've got 5 stock connectors that no longer go to anything. One is primarily for the headlight, one for instrument lighting, one for the instruments and I'm not clear on what the other two did on the stock bike. I'll dig into the wiring diagrams tomorrow. I'll also validate mechanical timing. I wire tied the cam chain to the cams before pulling them to shim the valves and visually the marks on the cams were correct before buttoning up the cam cover. Spark, air, fuel, and compression right?

I like it, well done

Handsome bike. Awaiting street legal additions.

tried to start her today on the baby bottle, no joy. Turns over nicely, spark at every plug tested with a color tune tool. My sense is something is amiss in the wiring. ---

Is there sign of combustion in any cylinder?

Spark plug wires attached correctly?





Good Fortune!

There are often a couple of accessories that are unused from new or disconnected, if your plugs are firing then then maybe coils swapped around as Patton has indicated.

If you have a spark and fuel I'd check your ignition timing with a strobe. Dynamic timing marks can be inaccurate if the crankcases and ignition pick ups are mismatched and different model years. I had this on a bitzer gpz550, subtle differences in crankcase castings between the years meant the pick up plate that I had marked from a donor bike was miles out, and needed to be slotted to time correctly.

I like it. The fenders look really good.

The not firing has to be something stupid simple.

No sign of combustion in any cylinder, not a single cough. The plugs wires are still factory plug wires with the numbers on them. 1,2,3,4 along with the factory coils, One of the few items not replaced with new parts. But it brings to mind the red and green wires to the #1 coil were pulled off. I've got the green wire on the bottom closest to the cam cover, red wire on the top. Opposite on the #2 coil, red wire on the bottom, black on the top. I don't see any + or - indications on the coils. Thank you for the kind words.

Tried starter fluid or squirting gas into the carbs?

The carbs were rejetted?

Great looking bike, thanks for showing

Carbs were rejetted, I can look up the numbers, but went up one size from stock due to the addition of the pods on the pilots and the mains IIRC. I can look it up in my records. Pods aren't my thing but the owner wanted them in a big way. To shoot starter fluid in the carbs I'd have to pull the pods. That will really hose up the air flow won't it?
This is the 5th set of BS34 carbs I've rebuilt. All the others performed spectacularly. I'm FAR from an expert, but know my way around these carbs fairly well.

It's just a way of eliminating spark or timing issues. If it will fire with fluid you know you have a fuel or carburetion issue.

I think I found my bug. The green wire runs from the ignitor to the #1 coil and then operates the left turn signals. The male green bullet connector without a corresponding female...goes to the stock GPz battery. I slipped in my KZ650 battery which does not have the separate GREEN wire female tap. I think I'm missing voltage to the ignitor straight from the battery.

Awesome!

I like that bike more every time I look at it. It's hard to believe it's a Ninja. I really like that it has fenders, side panels and doesn't have the ironing board seat