1981 KZ1000 J-to-K build

So I have two soaking in gas and two soaking in motor oil... will see what happens to them overnight... In the meantime, I was able to get the plugs out of the other carbs and they reseated tightly. Got the working set of carbs back together and on the bike.

All right so some observations. After the bike had run for a minute and the idle speed had dropped down, it suddenly went WAY down... like to 6-700rpm, and it was running *smooth* at that speed. Awesome! And then after a few minutes it started having problems and had to be held higher and higher. OK I'm pretty sure I know what this is -- the original tank had noticeable rust inside it, and I bet the fresh gas has been knocking it all loose. I've had sediment in the bowls every time I take the carbs apart, so that's probably where it is coming from. And I also believe this is what's clogging up the idle jets each time. I was thinking about this earlier in the week and ordered some cheap inline filters online, I just have to wait for them to arrive. That should help ensure only clean gas is getting to the carbs, then I just need to clean out the jets one last time.

When it initially fired up, it was a lot smoother than I have seen it. In fact if it had continued running that way I would have thrown the seat back on and taken a quick trip up and down the block. The fact that it CAN run that smooth certainly proves that all of my issues now are in the carbs, or the garbage that is being fed in to the carbs. Since I have some other things coming up in the next few weeks, including a short trip to the path of totality for the upcoming eclipse (something I've always wanted to see!), I think I'll just put the bike aside until those inline filters arrive, and then slosh some gas around the tank and drain it to try and reduce the problems. Hopefully at that point I can get it to run cleanly.

Oh yes, one other thing. It was still running hot on the right side, even though it actually felt like all four cylinders were firing now. Also as the carbs got clogged up again I was getting a lot of backfiring on the right side. Nothing like a fireball, but a rather constant bang ever few strokes. That's the first time this has happened, so I'm not sure if it's clogging in a different way now, or because of the added restriction of finally having an air filter in place. I'm pretty sure it's just another symptom of shit in the carbs though.

As for wether the bowls hold that plug in place... damn I never even thought of that! I just looked at one of the bowls from the other carbs, and sure enough there's a pin sticking up in the right place, so yeah it probably does hold them in. Ah well, at least now I know. I'll pull the original plugs back out of the oil and gas, no sense stressing the existing O-rings.

Well the yard sale was a total bust this weekend... I've never seen so few people driving around and you couldn't have asked for nicer weather this time of year. Ah well, at least I have some free time.

I guess all this practice with the carbs paid off. I decided to start tearing down the other set of carbs this morning and just whipped right through them. Pulled the plugs over the pilot jets, got the other jets, floats, and valves pulled out. Basically everything except the butterfly valves have been removed, and I won't do that. Made that mistake on a pontiac quadrajet once and could never get the plates to properly center again. I mentioned before this set of carbs had been shelved with the gas in them, so I had to really coax some of the parts loose. The slides I ended up painting in gas before they finally came free, but it looks like they are all still in good shape and just need cleaned. The floats and valves appear to be factory original. I'm not quite sure if there's an easy way to test the floats, but I'll probably just re-use the new ones from the first set of carbs. The rebuild kit I'm looking at comes with all three jets, needle valves, and the bowl gasket, so all the important parts will be nice and fresh. And since these may be apart for awhile, I went ahead and stamped the bodies of each carb with their position number. Figured that way I don't have to worry about keeping them straight when I put them in a tank for soaking.

Now I just have to find something suitable to really soak these clean. Most of the passages should flush out easily enough but I'm worried about that brass pipe that extends to the bottom of the bowls because the hole is so small. At least I have time to soak these clean, but I might have to find some really fine piano wire that will fit through the hole just to make sure they're clear.

[Edit] I forgot to mention, I also sloshed the gas around in the tank today and drained it back out through a coffee filter. I was expecting red flakes of rust but what I saw was this really fine black grit. It looks exactly like the stuff that's been clogging the idle jets so I think I'm on the right track. Might be worth pouring the gas back through the tank again just to see if any more comes out, but I still plan to wait for the inline filters before firing up the bike again.

I use a guitar string to clear the jets and the choke pickup tubes. They are jets too. My 33's have them and one at the bottom where the fuel goes in.
Steve

I wonder if that choke jet is the second hole I saw in the main bore directly behind the pilot jet hole? It looks like this second hole gets covered up when the butterfly is completely closed.

Secondary jet.
Steve

Secondary jet? More carburetor black-magic? Eesh. Well there was no evidence of any moving parts around it so I assume there's nothing that needs removed? I remember reading that most of the carb cleaners are really caustic to plastic and rubber parts (I assume similar to brake cleaner) so hopefully there is nothing in danger by leaving the butterflies and throttle levers in place.

I couldn't find the carb dip I was looking for today, but I did run across some discussion on using pine sol for cleaning carbs. So sure, why not? I dumped a bottle in a bucket and added water to mix it about 50/50. It's a small bucket so I can only soak two at a time, but it should be interesting to see the results. Apparently parts treated this way oxidize immediately, so I think I'll do a soda blast of the carbs afterwards. No sand around this set!!! Just want to give it a good surface to stick a coat of paint to. After the soda blast, I'll wash them down in the sink and then try to blast out all the passages with the air hose.

The fuel petcock rebuild kit turned into a nightmare. Got a notice the kit has been delivered on Thursday... Uh, no, there's nothing on the porch or in the mailbox. Called the post office, turns out a substitute carrier had marked the package as delivered and then forgot to drop it off, so I did actually get the kit in the mail on Friday. Too the petcock apart today. Well shit. The kit has a rubber ring with four holes, but mine has five. Did some digging and discovered someone has put a J petcock on the LTD gas tank. Ugh what a mess! Sent a note to the seller to see if they can swap me for the right kit or if I can return it (still unopened). In the meantime I discovered one of the screws holding the face plate was seriously bent. Hmm maybe THIS is why the petcock has been leaking? Picked up some new stainless screws and put everything back together. I won't be testing it until the inline filters arrive, so it's just sitting to the side for now.

I got the new bullet connectors soldered on the read turn signals last night. Still trying to understand the wires for the front signals. They look like factory connectors on the two blue, one green, and one grey wire. In fact I have the same connector types on both wiring harnesses. Yet I cannot figure out what kind of connector is supposed to fit in these things. Way too small for anything I have. Oddly the black/yellow ground wire uses the standard size bullets. Unfortunately these turn signals I got don't have dual-filament bulbs for running lights. I may experiment with adding a high-brightness amber LED to each of them though, but that'll come later.

The pine sol solution is working. Probably going slowly because I diluted it so much, but it's making progress. I think the first two carbs will be ready to come out tomorrow. I also dropped the slides in and they're looking better already.. I might have to take a brush to some heavier areas though, just have to wait and see,

So the connectors for the front turn signals appear to be 2mm bullet connectors. No luck finding anything like that locally so I had to hit up ebay. I have 10 pair of male/female gold plated connectors coming for only $1.50 but I imagine it'll be about 3 weeks before they arrive. At some point I need to pick up a new headlight as well, the original was heavily sand-blasted and it didn't seem worth even trying to use. Partzilla had a nice halogen bulb assembly for under $20 so that's what I'm going to try and get.

I wouldn't leave them too long in the pinesol...ive been told no longer than 24 hrs.
I have always rinsed the carbs immediately after removing them from the bath...blown dry and then sprayed down/wiped down with wd-40.
I havnt had any chalking/serious oxidizing doing this but apparently quite a few others have....
Good luck....if it doesn't work carb dip/carb cleaner....

So the slides soaked for one day and the carb bodies soaked for two days... Looking really good! I can still see a little build-up around where the primary jet screws in (although the holes are clear) and one of the butterflies is still a little stiff. I'll hit it with the brake cleaner to try and remove the last bits, but every other passage seems to be cleared out. The slides move smoothly through the bores now and there seems to be no issues with the diaphrams so I think this set will be usable as well. At the very least I'll have an extra set to swap out as needed. I have the second pair of bodies in the pine sol now. All four caps are also cleaned up, and I'll look at the bowls next. There were a lot of stripped heads on the bowl drain screws so I had to use some from both sets of carbs to make a full set. I'll have to re-check these bowls to see if there were any stripped threads but I'll probably just re-use the first set of bowls since they were already cleaned and inspected. I probably won't have time for a couple weeks, but I'll soda-blast these carbs and get them painted up... and hopefully have a better set than the first round.

Second pair of bodies are out of the soak. Every hole that I can see through is nice and clear, although I think the air hose blew out the last remaining bits. Two of the carbs had stiff butterflies, but after I gave the shafts a quick blast of brake cleaner it knocked out the last bit of varnish and now they all move nice and free. I decided to go for broke and threw all the bowl parts except for the floats into a strainer and have them soaking. Since there's rubber parts involved I'll only let them sit for one night but I've shaken them up several times this evening and a lot of the gunk is already off of them.

Since the engine and first set of carbs came with pods on them, and that set has obviously had the carbs worked on, I don't really trust that the jets are stock. Unfortunately the jet screwdriver slots have also been gummed up so I was never really able to read the numbers stamped on them to verify the size. This second set of carbs came from an LTD and is dead stock... honestly I'm not even sure if they had ever been cracked open before. Since I currently have to work with the best of what I have on hand, I think I'll be using this set of jets. And due to the amount of handling and gas leakage involved with actually setting the floats, I believe this time I'll set them up before I paint. Of course I've learned a lot more about working with the paint since I did the first set of carbs, so I probably won't have as much trouble with the paint coming off.