85 GPz 750 Cafe Project

ajsfirehawk wrote: Should the pilot jets on the bowl side be plugged? They are not. The more I think about it, that has got to be it. Holy cats. Who was it who said "Its got to be something stupid simple" ... egads.

Carb parts diagram doesn't show a plug for the pilot jet.

The following link should bring up the parts diagram.

Click here > www.powersportswarehouse.com/p/Kawasaki#...0-A3-1985/080186C-10

Good Fortune!

A pilot jet plug is shown for the KZ750-R1 GPz (1982).

Click here > www.powersportswarehouse.com/p/Kawasaki#...50-R1-1982/080112C-8

Good Fortune!

Spray exiting into the carb bore from being sprayed into the starter pick-up is good, but doesn't indicate that fuel is flowing through the tiny passageway from the main jet to the pilot jet, which tiny passageway may still be obstructed.

Using the same block and spray method for the pilot circuit, first remove the pilot screw, then block and spray into the main jet to see if spray exits through the empty hole where the pilot screw usually fits.
If spray exits through the empty hole, the spray is passing through the tiny passageway, which indicates that fuel can also flow though the tiny passageway.





If spray exits through the empty hole, replace the pilot screw, and again block and spray into the main jet to see if spray exits into the carb bore.
If spray doesn't exit into the carb bore, it indicates that the orifices in the carb are obstructed.

Good Fortune!

ajsfirehawk wrote: . . . pulled the pods off and shot starter fluid in, took off running light a bat outa hell. Possibly the paper filter on my baby bottle is clogging the passage of fuel to the bowls? . . . .

To just rehash some basics ---

Ability to run on starter fluid but not otherwise indicates an imperfect pilot circuit. And that for whatever reason fuel mixture isn't being provided by the carb.

Even with a perfect pilot circuit, sufficient fuel must flow into the carb, through the float valve, and into the float bowl.
A restrictive in-line filter can prevent fuel from being furnished to the carb, same as a kinked fuel line, or for whatever other reason why the carb thinks you're out of gas.

Be sure to use the type of in-line filter designed for gravity flow (such as for lawn mowers), and not an in-line filter that's designed for use with a fuel pump.

After an unsuccessful effort to start the engine due to lack of combustion, the spark plugs should be wet with fuel. Which indicates that the starter circuit and/or pilot circuit are providing fuel mixture from the carb that's being sucked into the cylinders.

And of course, remember to not touch the throttle grip when attempting to start a cold engine.

Good Fortune!

Great work, not sure about the fenders, more reminiscent of a solo bobber then cafe racer.

kzspartan wrote: Great work, not sure about the fenders, more reminiscent of a solo bobber then cafe racer.

Yep, this bike looks great, love the fact the the OP didn't use the stock tank, the Z tank gives it a great balanced look, the guards don't work at all with the rest of the bike, in my opinion...

I think the fenders look great. Probably more true to original cafes than not. I can't see Brit rockers raising hell around the UK without them. You can only get so hard core without being a little practical.

It has just the right elements of the cafe, tracker and bobber all rolled into one.

I also like how he's kept some of the original elements that are usually the first to be replaced like the exhaust.

GPzMOD750 wrote: ..... I can't see Brit rockers raising hell around the UK without them (fenders). You can only get so hard core without being a little practical.
.

Amen! I rode without a front fender on my BSA for a few days - what a mess! Ed

It may be meaningful to show what the owner originally brought to me as the target finished product. Some adjustments were made along the way as is usually the case, but you can see he had a clear vision of what he wanted. That was very helpful.

You did a great job executing it. Now get it finished and running. We'll christen it an honorary KZ and make it BOTM.

If you do a image search on "rocker motorcycle", "rocker racer", etc. All the authentic vintage images show almost 100% "mud guard" usage.

Patton wrote: Are the plugs wet with fuel after an unsuccessful starting effort? Which would indicate that the carb pilot circuits are providing fuel that's being sucked into the cylinders.

Here's one cleaning method:

Remember to wear eye protection when spraying carb cleaner, because the spray always backfires. Always.

Good Fortune!

I carefully read all the notes on the images Patton with regards to what to plug and where to spray. It really would help to have a third arm. Two hours and a can of carb and choke cleaner later, i cannot make anything come out of the enricher circuit or the pilot circuit. My confidence about having a quality 'seal' on the areas to be plugged is low. That coupled with a far less than perfect seal with the straw on the carb cleaner can. Maybe those things don't need to be perfect to get some flow out of the pilot or enrichner ports into the carb body. The lack of flow would certainly explain the fact it won't start. I was able to drop a carb wire down the brass tube and each of the openings in the carb bore. So what is the next step? Strip them down and back into the ultrasonic cleaner and jack up the heat?
Other house keeping. The baby bottle will flow like crazy into a pan on the bench with just gravity.
It was a good thought to remind me to put on safety glasses.

Patton wrote: The carb enrichener circuits should also be functional.

And the bowl passage must be clear so as to provide fuel for the choke pick-up tube.

The enrichener circuit (choke circuit) is designed to best function when the throttle is fully closed.
So it's best to not even touch the throttle grip while attempting to start a cold engine.
And it's futile to frantically and repeatedly twist the throttle grip open and closed while cranking over the engine in a attempt to start it.

Good Fortune!

Bowl passages are clear. No I did not touch the throttle grip when trying to start the bike. I did see a few bubbles at the pilot circuit port in the carb bore on Friday but could NOT repeat that today. It is really tough to try to match the carb cleaner can straw to the brass pilot circuit fuel pipe. Hard to believe there is much pressure that makes it into the pipe without some sort of tubing seal to act as a coupling.