carb rebuild and 1075 kit

Perfect! I'll verify all fuel supply issues first and then give that a try! Thanks for the help!

Got a good amount of rust gunk around the bottom of part of the petcock that inserts into the tank. Going to clean out the carbs again just in case. Guess it always helps to start with the basics!

I was running a stock 1015 with 29mm smoothbores and 120 mains on a vance and hines with pods and it ran nice, really nice.

Cleaned everything up and put it back together. Installed new motorcycle fuel filters. Took it for a ride today, I did notice a difference with the gas cap open, the choke didn't seem to make much of a difference.

If it is a venting issue, what can I do? I replaced the vent seal when I was working on it this last year because it was cracked and didn't seem to seal completely. Can the vent be cleaned/repaired if it isn't venting properly?

I ran what Patton does when I had the 26s on my 1105 motor. It has since been changed to 29s

Looks like I might have caused my own issue (pretty much par for the course, haven't proven it yet, though). I took apart the tank vent and looked it over, cleaned it up a bit, and I might have put a screw in the wrong place blocking the vent path. We'll see for sure this next week (once I get my tubes/tires replaced since I had a flat this weekend).

DD, Choke tip was a good one, since youve' rust issues and run inline filters, offer these. a carb clean is only as good as its fuel supply. any rust/debris which may have enterd since clean may be laying in bottom of float chamber, and be sucked up to MJet at wot. also routing fuel lines w/filters often requires inventive/presise locations. a line with a tight bend when heated can easily restrict flow. have been hose by both (repeatedly). luck g

I don't know guys. A 120 main jet in 26mm stock carbs with the airbox still on.....sounds pretty fat to me. That's generally POD Filter Main Jet territory.

If it were me, I'd put a 110 or 112.5 main jet in it.

The pull the enrichener lever on trick....is a great way to figure out which way you need to go.

If that makes it worse, remove the rear silencer portion of the airbox and the filter. Go for a ride. See if that helps.

If you find a foam or K&N filter that would clamp to the back of the airbox where the silencer portion attaches, then go that route and loose silencer section & the stock paper filter.

JMO

Larry C

Again, I apologize to the OP for hijacking the thread.

Thanks for the input guys. I don't think I'm dealing with a jetting related issue at this point. I was very much expecting to be on the very rich end of things at WOT with a 120 main. At this point I'm not seeing any signs of too rich on the plugs, pulling the enriching circuit (choke) on at WOT doesn't seem to affect the running at all (better OR worse) and opening the gas cap has had the most effect - that is most of the hesitating/popping went away. I think I'm dealing more with a fuel starvation than a jetting problem at this point. I just need to figure out what is causing it.

I'm starting with the gas cap vent and working my way down. The petcock appears to have caught most of the loose rust that had been sucked down into where it inserts into the fuel tank - very little made it into the sediment cup and even less into the fuel filters. Float bowls looked clean of debris. I'm going to check my fuel lines again and see if there are any hard kinks in them (thanks Gane!) and go from there.

Larry - I am missing the silencer and am running the K&N replacement filter in the airbox. I'm surprised that you recommend reducing the main jet size from the factory's 115 main with the displacement increase (903cc -> 1075cc) that was made - seems counter-intuitive to me.

If I can't find the starvation issue with the items I mentioned I will pull the carbs apart and make sure that the fuel passages are clear - it's possible that they have varnish/gunk in them as the bike sat for quite a while before I rebuilt it.

Thanks again all!

DoubleDub wrote:

Again, I apologize to the OP for hijacking the thread.

Thanks for the input guys. I don't think I'm dealing with a jetting related issue at this point. I was very much expecting to be on the very rich end of things at WOT with a 120 main. At this point I'm not seeing any signs of too rich on the plugs, pulling the enriching circuit (choke) on at WOT doesn't seem to affect the running at all (better OR worse) and opening the gas cap has had the most effect - that is most of the hesitating/popping went away. I think I'm dealing more with a fuel starvation than a jetting problem at this point. I just need to figure out what is causing it.

I'm starting with the gas cap vent and working my way down. The petcock appears to have caught most of the loose rust that had been sucked down into where it inserts into the fuel tank - very little made it into the sediment cup and even less into the fuel filters. Float bowls looked clean of debris. I'm going to check my fuel lines again and see if there are any hard kinks in them (thanks Gane!) and go from there.

Larry - I am missing the silencer and am running the K&N replacement filter in the airbox. I'm surprised that you recommend reducing the main jet size from the factory's 115 main with the displacement increase (903cc -> 1075cc) that was made - seems counter-intuitive to me.

If I can't find the starvation issue with the items I mentioned I will pull the carbs apart and make sure that the fuel passages are clear - it's possible that they have varnish/gunk in them as the bike sat for quite a while before I rebuilt it.

Thanks again all!

Make sure you check the design fuel level in the carbs. If it's off, you'll play hell trying to jet the bike properly.

I don't recall any 1015cc with 26mm carb and 115 Main Jets from the factory??? :huh: [maybe 76 900 LTD was that rich]I'd have to dig for my old Kawasaki spec manual to see.

US Spec 1000's generally had much smaller main jets. From 107.5 down to 102.5

The factory continually leand out the Z motors over the lifetime of it's use with 28 & 26mm VM type carbs.

Your setup with the replacement filter and airbox silencer removed is a good setup.

If you do have a fuel stavation problem, after correcting that, your bike may well like a smaller main jet. Only 1 way to tell....

Thanks Larry! I didn't realize that they continually made the jets smaller in the Kz1000's. I was just going off of what was in my Kz900-A4 from the factory. I know WG always stated that these were pretty rich from the factory, but I didn't realize that they had it that rich. I appreciate your input!

Thanks for the guidance everyone! The problem does appear to have been fuel starvation due to a malfunctioning gas tank vent (that's what I call it when I break it) and the rust accumulating by the petcock. I was actually able to get it up to 9000rpms this weekend without the hesitation there used to be. I definitely think I'm running rich now, but I'll let the plugs tell me the truth.