Z750 (L4) -84 will not start, vacuum ports?

So, here I am. Another fellow who has spent winter to totally rebuild the stock Z750 daily driver to a cafe racer. And of course there has to be another pod-filter-and-possibly-jetting-problem thread. Bear with me.

All new 4-1 stainless exhaust is fitted, along with rebuilt and cleaned carburetors and pod filters.

The following has been done with the carbuterors:
- 130 main jets
- 42 pilot jets
- Needle raised one stop (from third to second clip)
- Slide drilled (enlarged slightly according to jet kit instructions)
- Pod filters installed

Today was my first try on starting the bike up. It hasn't been started in the last 6 months. With everything rebuilt, including all new wiring, I started with just running the starter and checking spark plugs. All four new spark plugs light up nicely! Good, let's turn the fuel on and see what happens. Well, nothing. Every now and then I get a big pop from the exhaust, but the bike didn't starti in 10 good minutes of trying with full choke, no choke, fuel off and fuel on...

What I can't figure out is what I should do with the four vacuum ports on the carbs. I have two rubber plugs on the outer two carbs, but nothing on the inner two. See picture below circled red. Should I block all four, or none of them? What do you normally do with the vacuum ports after installing pod filters?

There also seems to be a problem with carb #2, since I'm getting fuel spewing back out through the filter. This started happening after a few minutes of trying to get it running though. I guess I might have to tear it all down again and have a look. I was very careful cleaning and installing the new jets. Diaphragms looked good.

Last question is mixture screws. I currently have them turned out 2,5 turns (screwed them all the way in and backed out). This should be a good starting point. Right?

If you have a vacuum petcock then you should connect one of the ports to the vacuum port on the petcock with a hose. The rest should be capped. You can get caps at any auto parts store.

The popping may be because you have the coils wired backwards. This happened to me when I rebuilt my 1100. Double check the leads against the wiring diagram in your manual. Or you could have the timing off.

I forgot to mention I no longer have a vacuum petcock, just a fuel line with an inline petcock and filter. So this means I should cap off all vacuum ports, right?

Will also double check the wiring to the coils. You could actually be on to something here! I think the bike should definately have showed some sign of life.

I'll get back to you soon.

CCrosswait wrote: If you have a vacuum petcock then you should connect one of the ports to the vacuum port on the petcock with a hose. The rest should be capped. You can get caps at any auto parts store.

The popping may be because you have the coils wired backwards. This happened to me when I rebuilt my 1100. Double check the leads against the wiring diagram in your manual. Or you could have the timing off.

I can't thank you enough! That was it!

I capped all vacuum ports. I then swapped the leads to the coils over and the bike started straight up.

The bike Idles and seems to be working OK when you rev it in neutral. Will need some fine tuning when I get it down on the ground, but I'll get to that another day.

Man it felt good hearing it rumble after 6 months on the lift!