Help Diagnose my No-Start

There is fuel in the filter for sure, when i turn the petcock on i can see fuel flow into it. Im gonna take them off again and see if i screwed up something simple.

Probably clogged carb enrichener (choke) circuits and/or pilot circuits on both carbs, meaning not perfectly as-new clean.

Here's how the pilot circuit is supposed to function:


Here's one way to finalize cleaning the pilot circuit:


Diagrams of the various carb circuits are shown in the factory service manual (aka "FSM").

Good Fortune!

Mickey Mouse Carb Overhaul:

For people who don't want to tear the carbs down.

1) Drain the carbs at the drain screws.

2) Pour cleaner in the carb through the fuel lines and fill the bowls. Tape off and let sit for a few days.

3) Remove drain screws. Hose down and into the carbs through the fuel inlet pipe with carb cleaner spray and let it run through. Keep hosing.

4) Drain and run with cleaner in the fuel tank.


FOR THE RECORD:

The jets are in the float bowls on 750 twins. The main jet is at the bottom under the drain screw. The pilot jets are at the top of the bowl.

With a suitable screwdriver, you can take the bowls off with carbs on bike). You can then soak the whole bowl in cleaner to clear everything.

Patton wrote: Probably clogged carb enrichener (choke) circuits and/or pilot circuits on both carbs, meaning not perfectly as-new clean.

Here's how the pilot circuit is supposed to function:

Here's one way to finalize cleaning the pilot circuit:

Diagrams of the various carb circuits are shown in the factory service manual (aka "FSM").

Good Fortune!

Wow that is beyond helpful!! Ended up taking my wife out for dinner so I didn't have time to work on the bike tonight, but I'll definitely do it tomorrow. I'll update you guys once I run through the carbs again.

Thanks so much for the help and for being patient with me!

bountyhunter wrote: Mickey Mouse Carb Overhaul:

For people who don't want to tear the carbs down.

1) Drain the carbs at the drain screws.

2) Pour cleaner in the carb through the fuel lines and fill the bowls. Tape off and let sit for a few days.

3) Remove drain screws. Hose down and into the carbs through the fuel inlet pipe with carb cleaner spray and let it run through. Keep hosing.

4) Drain and run with cleaner in the fuel tank.


FOR THE RECORD:

The jets are in the float bowls on 750 twins. The main jet is at the bottom under the drain screw. The pilot jets are at the top of the bowl.

With a suitable screwdriver, you can take the bowls off with carbs on bike). You can then soak the whole bowl in cleaner to clear everything.

I'll probably just dissassemble and clean again and be more thorough this time. Thanks for the suggestion, good to know that this is a method as well.

And just to repeat, after a good thorough cleaning, absolutely make sure the float levels are properly set (via the clear tube method). Everything depends on it.

bountyhunter wrote: . . . The jets are in the float bowls on 750 twins. The main jet is at the bottom under the drain screw. The pilot jets are at the top of the bowl. . . .

Thanks, bountyhunter!

Here's an excellent article about the early KZ750 twin carbs:
Click here > www.wgcarbs.com/index.php/using-joomla/e...gories/93-kz750-carb

I believe, but not positive, that the following are KZ750 twin float bowls with jets in the bowls:


Other than the following pic in the FSM, I haven't found a photo showing view into the bottom of the carb after float bowl has been removed.


Here's my effort toward a corrective image showing where the carb spray may be directed so as to exit through the orifices into the carb bore.



Critique is welcomed, as i would like to get this image refined so as to be most beneficial and as correct as possible.

For example, the FSM photo shows the float removed, but is float removal necessary in order to access the hole into which cleaner is sprayed for exit into the carb bore?

Good Fortune!

All passages in the float bowls should also be cleaned and clear and unobstructed.
A small stiff wire such as a guitar E string may be helpful.
And carb spray may also be used.
I don't know how the passages are routed in the float bowl.
But spray directed into any hole should exit from one of the others.

Good Fortune!

I swear this is the most helpful forum ive ever been on, thanks everyone!

Patton wrote:

bountyhunter wrote: . . . The jets are in the float bowls on 750 twins. The main jet is at the bottom under the drain screw. The pilot jets are at the top of the bowl. . . .

Thanks, bountyhunter!

Here's an excellent article about the early KZ750 twin carbs:
Click here > www.wgcarbs.com/index.php/using-joomla/e...gories/93-kz750-carb

I believe, but not positive, that the following are KZ750 twin float bowls with jets in the bowls:

Other than the following pic in the FSM, I haven't found a photo showing view into the bottom of the carb after float bowl has been removed.

Here's my effort toward a corrective image showing where the carb spray may be directed so as to exit through the orifices into the carb bore.

Critique is welcomed, as i would like to get this image refined so as to be most beneficial and as correct as possible.

For example, the FSM photo shows the float removed, but is float removal necessary in order to access the hole into which cleaner is sprayed for exit into the carb bore?

Good Fortune!

It appears the jets rely heavily on the gasket to preform as intended. If there's a leak in that area, the jets won't meter correctly. The gaskets have to be as new condition for them to work. :dry:
Steve

Patton wrote:

bountyhunter wrote: . . . The jets are in the float bowls on 750 twins. The main jet is at the bottom under the drain screw. The pilot jets are at the top of the bowl. . . .

Thanks, bountyhunter!

Here's an excellent article about the early KZ750 twin carbs:
Click here > www.wgcarbs.com/index.php/using-joomla/e...gories/93-kz750-carb

I believe, but not positive, that the following are KZ750 twin float bowls with jets in the bowls:

That looks like the correct bowl but the jets appear to have been removed from them. I believe the pilot jet would be visible on the top surface in the smaller hole near the brass overflow pipe.

Ok so I took the carbs off to do the clear tube float bowl test. I got the first carb perfectly set. Went to do the second carb and no fuel would come out of the drain plug??? Gas VERY slowly goes down the funnel and gas line I was using to feed the carb, but none came out of the drain. When I took of the float bowl again it was wet with gasoline in there (though definitely wasn't filling up all the way). The floats move freely and appear to be operating perfectly.

Thoughts?