1981 KZ1000 J-to-K build

Well we survived the eclipse on Monday, and more importantly the thousands of people jamming up the roads when trying to get back home. Got some great pics from my little camera and now thinking I really gotta go see the one in 2024... but that's for another day.

Today I finally broke out the sandblaster to work on that second set of carbs. Since they are pretty well cleaned up I just wanted to prep the surface for painting, but I still had to pop the pins from the throttle adjusters so I could remove than and their associated hardware. Ugh. Spend two hours trying to get out the pin on #1 and barely even moved it. Finally grabbed another carb, and the pin drove right out. Grabbed the third one, and again the pin came right out. WTF??? At least with a clear hole I could see the proper size of drift needed, so I chucked a big nail in the lathe and filed it down to size. Had to really get creative in propping pieces underneath the aluminum piece so I didn't bend the butterfly shaft because I had to use quite a bit of force to get that pin to finally start moving. That was way more effort than it should have been.

Finally with all the pieces removed, I dropped a banged-up bowl and cap on the body, put a bad choke in the hole, filled the screw holes and taped off the rest. NOW I could start sandblasting... And that went easy as can be. I used soda the first time around and I don't think it roughed up the surface for the paint to bite, so I used sand this time and left the surface looking more dull than polished. Blow everything out with air, a final blast of brake cleaner, and a quick run to the store to pick up a couple new cans of paint.

So the first two carbs are finished, and the other two should go pretty quickly tomorrow. They're getting the cast-iron color engine paint this time so they match, and since I actually have everything removed I'll go ahead and bake them in the oven to really set the paint. I also painted the two mounting bars gloss black to match the rest of the framework, and I think the color difference will be a nice detail. If I have time I'll also go ahead and sandblast/paint the four caps tomorrow, then I can bake all these parts together later in the week. That will just leave the bowls to do after I set the floats in the new carbs, and those bowls are coming off the first set of carbs so I'll have to strip the old paint.

The small connectors for the front turn signals came in today. Maybe I'll get time to solder those on tomorrow. I hope the inline filters arrive sometime this week, I think the new set of carbs are going to be ready to put on the bike next weekend.

As a parting thought, here's a giant hole in the sky...

Just a quick update tonight... all four bodies and top caps are painted and the throttle levers have been put back on each. I spent a little time cleaning and polishing the idle screw (it was caked with grime), then rubbed it down with WD40. Hopefully the fish oil penetrates the steel and helps it stay nice looking for awhile, but the screw really polished up nicely. On the original carb I had tried painting the lever that the throttle cable wraps around... of course with the constant friction of the cable, the paint is pretty well destroyed. The piece from this set darkened up considerably in the pinesol, almost like an antiqued bronze color. I finished cleaning it with a soft steel brush and it retained that dark color. I think it'll be perfect against the cast-iron color, and the bare metal won't be affected by the cable.

I started putting in the jets before I remembered that I still need to bake everything. Figure I'll give the paint 48 hours to cure before putting the pieces in the oven, although this Duplicolor paint is actually dry to the touch in less than an hour. Once everything is baked then I'll screw in all the jets. It's about time to pull the original set of carbs off the bike for the last time, drain the bowls, and pull them apart. I need all the choke parts, the bowls, and all my stainless screws to reassemble the new set.

One promising bit from today... The top cap I was using to seal the bodies during paint is actually going to be used on the new set, so I had to strip it back down to bare metal again before giving it a final coat of paint. And it took a lot to get it stripped. Just along the edge where it got an initial blast of sand, the paint was so well attached that the sandblaster didn't remove most of it. I has to use a putty knife to scrape it down, and then take more time with the sandblaster to get it cleaned up. That gives me hope that the paint is sticking very well to this new set of carbs.

It's been a hell-week at work, shit went bad causing lots of OT, but I did manage to sneak in a bit of work. The carbs got bakes on Wednesday with good results. A couple of the butterflies were still a little stiff despite the pinesol soak and lots of brake cleaner on the shafts, but after baking they're snapping nicely against the springs. There's probably still a little varnish left in the nooks and crannies, but a little time and flowing gas should clean out the rest. So all the pieces have been baked, I've got the jets back in and tonight I pulled the original carbs from the bike and drained the bowls. Tomorrow I'll pull the floats and start getting them set in the new carbs, and then get the whole set reassembled back together.

Unfortunately still no sign of the mail-order inline filters. If they don't show up in tomorrow's mail I may have to just grab a single from the local store. As much gunk as I've seen in the tank, I may go through all of them anyway before I have the new tank ready.

Well... Crap... The inline filters showed up today. They only have 1/4" barbs on them. Not sure how I missed that when I ordered, but I did. Grabbed one from the parts store today, will just have to go with that for now.

Meanwhile I dropped a couple gallons of cider vinegar and a gallon of distilled water into the gas tank today. Been sloshing it around every now and then, there's a lot of stuff floating already so I think I'll let it sit overnight. I have one more gallon of distilled water to do a final flush of the tank tomorrow. Unfortunately the petcock is leaking worse than before. Will have to take it apart again and see if there's anything I can do.

So the new set of carbs have been assembled. Definitely a mess, but perhaps it will do until I can get a rebuild kit. One of the newer float values wouldn't seal up, could have been causing a problem before. I ended up with two carbs using the newer valves and two carbs using the stock valves. I don't think any two have the floats set at the same height, but they've all been adjusted so the fuel level is 3mm below the top of the bowl, and that's the part that matters. I took the bowls from the original set of carbs, they haven't been painted yet until I'm sure the fuel level is correct so they look really out of place.

I also found the boot on one of the chokes had a hole in it. Swapped that out with another, but that was probably yet another air leak in the original carbs. I should get a new set of choke boots some day, they all seem to be original and fragile.

I'm ready to put the new carbs on the bike tomorrow, and if I can get the petcock to seal back up I'll put the tank on the bike too. Just hope everything is clean enough to run smoothly this time. I'm crossing my fingers that it runs a lot better now. Once I have it running reliably then I can finally start in on actually tuning the carb. Wouldn't THAT be something?

Busy day, but I got a bit done. First off the gas tank... whew what a LOT of crap the vinegar soaked loose! I got most of it dumped out, then flushed the tank once more with the last bottle of distilled water. Let it sit in the sun for a bit and used the compressor the blow out the rest of the water every few minutes. The last flush certainly drained out a lot cleaner, was almost clear. One unfortunate thing I noticed... the tall filter on the petcock is missing the rubber stopper from the end of it, and it looks like that means the gas can flow right into the petcock unfiltered. No wonder I was getting so much crap in the carbs before.

I pulled apart the petcock again to try and seal it up better. The wavy washer under the lever was a bit flattened so I applied some new bends around it. I also brushed a little synthetic grease on the rubber seal. Got it back together and wiped it down, and it seems to be sealing up properly now.

The new bank of carbs slid right in place. I got the inline filter fitted onto the line so I should be getting a lot cleaner supply of gas to the carbs now. The bike definitely looks better with the carb paint matching the engine...


It took a bit to get the bike to fire up. I finally resorted to a shot of ether, and got it running. Further restarts worked just fine without the ether. I had it running for a good hour just sitting there at an idle. That's the longest the bike has run for me so I got to play with the primary jets a bit, but they didn't really seem to have any effect closing them down a turn or two (I started at 2.5 turns open). The engine is still stumbling a bit though so there's probably still a bit of crud to flush out and I still have vacuum leaks. I sprayed a bit of ether around the head boots and got an RPM increase from all four of them. Not sure if there's anything I can do to make these things seal up? After awhile the RPMs went up and it started having trouble idling again, so I've probably flushed some more crap into the idle jets. Since it had a good run I want to re-check the float levels before pulling the carbs apart and cleaning the jets again. I also checked the battery as I went, and while it did slightly charge from the bike running, it was never enough to keep it running reliably. With the battery pack hooked up I was getting a solid 13.9V from the alternator, however when I turned that off the motorcycle battery couldn't hold more than about 9V. I'll have to think about getting a new battery, just not sure I want to get one right before the cold season arrives.

And finally, I broke out the soldering iron and got the new connectors fitting on the front turn signals. Hmm still not quite the right size but they'll do for now. I got some 2mm banana plugs but I think I might need 2.5mm. The plugs just barely hold themselves in place with a friction fit, so just slightly larger should be right. They've good enough now that I have turn signals though.

Looks good.
Steve

Thanks. They'll definitely look better once the bowls are painted too. Good news is this paint is a lot more gas-resistant that the original black paint was. While messing with the tank and inline filter today I managed to dump a bunch of gas over everything. I just hosed down the bike and it didn't do more than dull the finish a bit. I've also been finding that the paint seems to stick a lot better to the parts I didn't put any primer on. Seems odd, the primer was from the same manufacturer and also meant for engines, but I keep seeing chips in the paint that leave the primer behind, The carbs were done with straight paint, nothing else, so we'll see how that lasts. Of course this points out one of the reasons why I wanted to go with a DIY spray-paint job in the first place... if something gets chipped, I just clean it up and spray a new coat.

I'll have to try this again using an air brush, but I guess it turned out somewhat ok for a quick try with a can of spray paint...



It's pretty much the style I was going for, and doing a final coat in the orange really cleaned up the bottom edge so it fades off nicely, I'm just not too happy with the detail of the scales. Ah well, I'll keep practicing.

Well it's been a cold Winter but we're finally starting to get some warm weather again... or at least we HAD some this weekend until a storm started moving in this afternoon. Been a busy weekend but I wrapped up with getting a new battery for the bike. I also got a rebuild kit for the carbs for christmas, so once we get another break in the weather I'll pull those and get all the crappy parts replaced. After swapping the battery I tried starting it up, but I think the carbs were too fouled when I left it last Fall. Backfiring horribly and doesn't want to stay running except at high RPM so I'll leave it for now. Sounds like we might have more warm days coming again next weekend so I'll keep my fingers crossed.

This is going to be it -- the year I finally get her running. I only expected to take half this much time but then again I never expected to have to fix so many things. Honestly though I think I'm still under two grand for everything plus I have a number of extra parts to re-sell later which should recoup a few hundred dollars.

Will also have to finish the paint. I still have the old tank on the bike, and the new tank has been sitting in the garage all Winter, so the orange should be nicely cured by now. Will experiment with the scales some more on the side covers and fenders before trying to finish the tank but there's no need to rush it. I have everything I need to keep the bike running while working on these other parts. Oh yeah, one other thing -- the plastic fillets I glued in behind the the tabs on the sides covers held up through the Winter (lots of temperature shifts that I thought might break the joints) so when I pulled off the cover to swap the battery it had no trouble coming off or snapping back into place. Glad I won't have to worry about those breaking now.

So.. thus begins a new year. Can't wait to actually be able to take her for a ride around the block!

One of the issues I ended last Summer with was a leak around the intake boots between the carbs and manifold. Now I'm not sure if that is having any affect on the carbs, but I do know it will have a significant effect on how well the engine runs through the range of RPMs when I get to that point (not to mention it makes it rather difficult to sync the carbs! ). As a temporary solution I got some copper Permatex (rated to 700 degrees) and put a thin layer on the ring where the boots seat. While in the process of getting the first boot ready, I suddenly noticed that the boots have an orientation... The bottom screw hole has a square shoulder while the top one is rounded. Wow, that could have been the whole reason I was getting vacuum leaks before. Ah well, there is also some light cracking in the rubber so I might as well make sure they're sealed this time. I got all four back in place paying attention to the orientation, so one way or the other there should be a good seal now.

I'll be getting to the carbs tomorrow afternoon. After all the times I did it last Fall, it shouldn't take much to pull them apart and get in the new pieces. Unfortunately this means I'll have to level the floats again, and that does take some time. I dunno, if things go well there's a chance I could actually ride it up and down the street tomorrow. I won't hold my breath though...

Keep trying you'll get there.
Steve

Thanks. I never had any doubts I *could* do it, but with all the other things that come up each Summer it has really drawn out the time needed to get this project done. And even getting the engine running still leaves a lot of work to be completed, but at least at that point I can get some plates on it and start working on tuning and the paint details. There's a few minor details to look into as well, like why the odometer box doesn't want to sit down flush on the bracket so I can put in the little pins.