New Member with few questions on my 1980 KZ1000 B4

What is up gents. Am new to the site here and thankful a forum like this exists that can help me get my ’80 KZ1000 LTD back on the road. Its my first and only bike, purchased over 30yrs ago. It hasn’t been on the road for over 5+yrs so I’m trying to work through a few things that I am going to need your help with. It’s a bone stock 1980 KZ1000 – B4 LTD, equipped with the stock Mikuni VM28SS carbs (w/airbox). I’ve changed all the fluids (brake, fork, engine oil and filter), gone through the ignition system (ie checked voltage and connections through the system, new plugs, checked coils, pick-up coils, plug caps, resistor), and pulled, cleaned, and relubed the drive chain. Am now down to the carbs which I have pulled and sonic cleaned and am now reassembling and have a few questions.    So the carbs are stock Mikuni VM28SS with the idle mixing screw found on the side of carb (was factory capped) and with an accelerator pump on carb #2. The carb slides themselves have a small notch on the bottom (notch is facing towards the engine, see photo). So here are my questions:
(1)   I drilled out / removed the factory installed plugs covering the idle mixing screws. All four of the idle mixing screws bottomed out at 1 1/8 to 1 ¼ turns. For reinstall, does this setting still sound correct to you?
(2)   I need to manually set the slides. My Clymer book (which doesn’t cover the B4 LTD) says to set the slide (from the engine side) so that there is .5mm to .7mm of clearance between the bottom of the slide and the bore. My slides all have a small notch in bottom of them SO is this .5mm to .7mm measurement made within the slide notch OR is it made immediately to the right or left of the notch? Have a look at the photo.(3)   Manual setting of floats: the Clymer book says prelim settings should be done as follows: turn carbs upside-down and check the float level. The float level should be 25-26mm above the carb body.
(4)   I have a gravity petcock (2 outlets) and my carbs have 2 inlet T’s (1 each between carbs 1 &2 and 3&4). The primary setting on the petcock fed into the T between carbs 1&2 and the reserve setting on the petcock fed the T between carbs 3&4. Assume these connections are correct?That’s it for now. Am sure will be back with another 100 questions. Thanks in advance for your help.      

Welcome to the forum!  That's a great story about keeping your bike all these years.

First off, Clymer's manuals are pretty iffy.  Better than nothing, but I'd get a factory manual for better info.  You can check the Filebase here to see if there is a free download.

1.5 turns open on the pilot air screw is a good starting point.  After you get the bike up and running, tweak this setting until you achieve the highest idle speed for each carb.

The slide height setting is just to get the engine started.  Just make sure each slide is roughly equally set, and once you get the engine running, perform a vacuum sync and set the idle speed where you like.

 

Welcome from the UK, love to see some pics of your ride.

Some additional stuff to help Lewis. Make sure to check that accel pump diaphragm membrane! If it's original and been sitting in dried-up fuel for some time a good chance it's going to be stiff/crunchy like a cornflake. This renders the accel pump feature either completely non-operative or spotty fuel delivery at best. These pumper style HAVE to have that working or you'll have a big-o flat spot off idle. Double check that #2 bowl that holds the pump! There's a singular ball bearing and spring underneath that brass flat plug you see at the bottom. Even the best attempt at sonic cleaning doesn't get the crud out, has no where to go? Even if you did rattle it loose, if not purged before assembly, debris will flow up and clog one or more of those fuel nozzles. It's a check valve and keeps fuel pressure going to the nozzles and not back to the bowl. And those two fuel hose tees, do they swivel freely or takes a bit of pressure to move them? If they freely move, then most likely you'll get weeping in one or both sides. Just want to address all these issues before you have to do it twice..or more. Might ask Nessism about his bounty of rubber bits, he has kits!! Have fun!        

   Welcome to The aZylum, a little air-cooled corner of interwebs Motorcycle Madness.

   1) In a perfect world, the air screws will go into the same carbs they were removed from when cleaning.  Mama Kaw likely set them on the lean side when capped to keep EPA happy.  Nessim's advice is spot on for final adjustment.

   2) That 0.5 ~ 0.7mm procedure is called a 'bench sync'.  It's only to get the initial adjustment in the infield, so to speak, prior to final sync using vacuum gauges.  Measurement is done in the notch.  We use a piece of piano wire, but a straightened, small paper clip will serve too.  Feel for approx, equal, tiny amount of resistance when moving the wire in the notch as adjustment is made.  Another method is to orient the rack vertically, so the notch in the slide is facing down, and carefully adjust to where the wire just barely drops out under its own weight.

   3) That 25 ~ 26mm should be reasonably close.  We don't have a 1980 KZ1000 – B4 LTD FSM.  Older carbs are done using a cleat tube method by which true fuel level +/- 1mm in the float bowl can be observed.  If a clear tube is recommended in the FSM, that's one way to go.  We wrote extensively about an alternative to a clear tube in an ongoing post not long ago.  The linked post below is addressing float setting on Z1 carbs, but yours may be same or very similar depending on what is spec'd in the FSM.  Link below:
www.kzrider.com/forum/3-carburetor/61368...n-setting-fuel-level

   4) We've never seen a dual-outlet petcock that doesn't share a common outlet supply from the petcock sediment bowl.   We don't have a 1980 KZ1000 – B4 LTD FSM or bike to observe, so we'll have to defer to other members who have same or similar.

Good Ridin'
slmjim & Z1BEBE

Hey Jim! They had a lot of variations of the 1980 model year 1000 VM28 pumpers depending on model (LTD, Shaft, Z1R Mark2 and Police) and country destination. Singular or dual feed, fixed jet needle, smaller (capped) air screw, slide design, etc etc. The ultimate EPA driven carb. A couple examples of the 1980 B4 and E2 shown, more in the tupperware containers. Soo humid here the camera fogged up from the air conditioning to outside ha.   

Hey Wookie - was working on it earlier and snapped this pic. Now the bike is in process as you can see .. I pulled the tank, side covers, and rear faring, and a fw other things off as I try to get it up and running. As you can see, its non in the greatest condition. The gentleman who I had purchased it from lost his garage space and had it outside (covered) here in the northeast US for prob 2yrs before I bought it. I had to do a fair amt of work initially / replacing a number of things BUT had it running for a good 20yrs before I stored it 5-6yrs ago. I'll update with photos / progress as I get it back together. tx again for all your help here.

   

Hey Asphalt - tx for all the good info here. The T's are in good shape (no leaks, pivot fine) but took your advice and replaced the square accelerator pump internals. Now have a follow-up question here as it relates to the setting of the accelerator pump rod, specifically how to set it up so that it functions properly. Was trolling around on the inter-web and found some info that said there should be 10.7 to 10.9mm of the bottom end of the rod showing (below the notched screw) BUT when I make this setting on my carbs, the accelerator pump fully activated .. and thats before any throttle is given. Even setting it 1/2 of this (~5mm exposed) seems to leave the accelerator pump almost fully engaged. So any advice on how the set up this accelerator pump / amt that should be exposed rod OR the amount of travel on the accelerator pump lever would be greatly appreciated. The accelerator pump rod itself appears to be working properly meaning the internal spring itself thats contained in the upper part (in the silver part of the rod) moves freely. Here a few photos of my "in process" carbs, specifically the accelerator pump and rod.      

Hey SlmJim - tx for the good info here. So performed the bench sync from inside the notch with the .5-.7 wire, so all good there. Took your advice and the great info you posted and decided to build a jig to perform the +/-1mm clear tube setting (my carbs called for +1/-1mm from 4mm below). Def a bit trial and error but in the end, got em all set-up to spec. Here a photo or two of the clear tube set-up. Tx again for all the good advice.   

Good Morning Lewis! Yes 10.7-10.9mm nominal thread length is what is stated but this is with using the original thickness OEM bowl gasket or stacked total height. You have to realize this too is adjustable. The Z1R 1980 with almost identical arrangement, used the same 46102-1013 rod, was set at 3.8mm. What may appear as fully compressed may not be. When set at 10.x and you rotate pulley does the lever on pump move at all or is it bound? The only thing length of exposed thread does is provide a longer time of spraying out the individual carb nozzles. Shorter length exposed threads more total fuel, longer exposed threads less fuel, I always bench test my pumper sets but you can do the same by installing set without airbox. Fill only #1 and #2 fuel tee from tank or whatever you've been using and verify a constant spray from each nozzle. Turn that brass slotted nut in/out until you get a constant strong stream of fuel when coming off idle. After you're happy with setting turn in brass nut and apply a small dab of blue loctite on exposed threads. Turn back out to happy setting so Loctite gets between threads and nut, otherwise that brass nut will rattle out.    

Tx Asphalt - so when set at 10.7mm. the pump is fully bound / the pump lever doesn't move at all. The spring thats contained inside the rod (upper thicker silver section) is what gives the slack for the throttle to move. It is unfortunately like this all the way down to 7mm where it starts to fee up / isn't fully bound BUT even at this 7mm setting, the pump lever barely moves & appears fully depressed. Maybe my carb set here has a different rod (like the one u mention). Also, I went through another check / mechanical sync of the slides. I first checked the clearance at the idle adjust screw so the distance between the throttle cable bracket and pully stopper = 1.8mm and then I checked that each of the slides has .7mm of clearance from inside the notch of the slide. I did this just to make sure some setting in the idle adjustment screw wasn't set improperly.

Like you say, given that the carbs are still off the bike, I'll toss them in a vice and set the screw when a constant stream from each nozzle when coming off the idle setting. As far as this constant stream, am I looking for it to spray out in any certain way? How forceful of a stream am I looking for? Thanks in advance here for your help. Much appreciated.        

Got ya. OK, forget all about the thread length and focus on what's really going on. What You're trying to attain is, with idle screw backed out, the metal pump lever where it's flat next to it's housing Parallel. The reason i mentioned "stacked height" is because i don't/haven't used paper gaskets for years. This pushes the whole bowl assemblies further away albeit slightly but can factor in. They made two different pump rods for these 46102-1013 and 46102-1007. I highly doubt yours had been changed but ya knever know?? Try putting a 1/64" singular ball bearing inside the pulley side of housing (aluminum sleeve) and assemble/thread brass. This will increase total length of rod assy approx 4mm. Note the differences between the two different rods, one sleeve is longer.