1981 KZ1000 J-to-K build

While I curse my many problems in other threads, I thought I'd post an updated pic from yesterday. This is the first time the bike has truly been back together in who knows how many years...



Most of it is stock. The handlebars, grips, mirrors, and turn signals are all custom, and the front brake master cylinder is from a police bike. However I did meet my goal of taking a J and converting it into a full-featured K. The notable changes were in the electrical options, for which I was fortunate to have a complete wiring harness (now using only components that did NOT have non-factory splicing or connectors, and there were a lot of those!), but I had to buy a new odometer which contains additional feature like automatic turn-signal cancel, and a new left-side switch cluster which has different connectors and probably different internals. The seat and gas tank are also different between models. Oddly enough the original bike came with an LTD tank but of course there was no way to bolt it down on the frame.

The only part I know I'm actually missing is the grip bar behind the seat, however I intend to install a short sissy bar, something with just enough padding to keep my wife from falling off the back, so I didn't see the point in trying to buy a replacement grip bar. Otherwise once the new tank and side covers are on the bike it should be complete.

I thought it would have a KZ tail.
Steve

Eventually... I have the tail and welded mounting brackets on the frame before I painted it, but this requires building a custom seat pan to go over the front edge of the tail. Building a new seat will be a project of its own, and I'm more focused on getting the thing running this year so I can ride it next Summer.

A quick run-down of the things accomplished today...

Starter clutch repaired -- two of the three rollers were not sliding freely. Replaced them from the spare parts bags and the starter is working beautifully now

The #4 manifold rubber boot was not sealing. Replaced it with another part which dropped right into place like the others. Had to tighten the bolts on all four boots.

Cleaned sand out of the idle jet passages, and then cleaned the idle jets. All four were plugged, thus leading to the refusal to run at lower speeds.

It's idling at just under 1000rpm now, definitely getting closer. I ordered a new air filter, will see what affect that has on how it runs. God I hope there's not more sand in the carb passages. I thought I had everything covered or taped when I cleaned the carb bodies. Maybe I'll just blame it on PO. The other issue is that the right side is running a lot hotter than the left, both the engine and exhaust. Whatever is causing that is likely also contributing to the problems with it running smooth.

A couple things around the transmission... I noticed when the idle speed is low, there's a rattling sound. If I pull the clutch, the rattle goes away. This sound stop when the engine speed gets above 1000rpm. I loosened up the tension on the clutch cable and it seemed a little better but didn't go away. I also put it into gear for the first time while running. Holy crap that thing just SNAPS into gear with a pretty loud pop. Is it supposed to be that aggressive? There was no problem with the clutch adjustment, the bike never tried to move while holding in the lever, and when the bike is off I can flip the shifter by hand and it smoothly rocks between 1st and neutral.

Next week I'll be able to buy a new battery for the bike. I've been using my jump-start pack to run it so far, but you can't exactly put the seat on with that thing hooked up. Once I have the battery I can try riding it up and down the street and see how it shifts between gears.

Surprisingly, I still have one piece I need to finish this weekend -- the chain guard. It's been sitting in a box patiently waiting, but if there's a chance of riding sometime soon then I need to get that cleaned and painted so I can mount it on the bike. Other than that, I'll just keep plucking away at the problems with the engine until it's running smoother.

Oh yeah, something else I forgot to mention... My neighbor from two doors down stopped this morning as I was working on the bike. Apparently he has a '76 or '77 (I can't remember which, he said it was the last year they were made) KZ650 sitting in his garage. I guess it hasn't run in years, but he said that thing would wind up faster than he could switch gears. He's probably in his 70's, so I'm guessing he stopped riding it because it was just too much power for him since I've seen him riding a moped around the last few years. Still, one has to wonder what his plans are for it...

Ask him. Great little bikes.
Steve

You know, I really thought about it for a split second... and then I thought better. Of course it's probably in a lot better shape than what I'm working on, but I really can't justify having TWO bikes.

One for your lady?
Steve

That'd be fun, but she won't ride. I'll be lucky to get her to ride with me once in awhile. Not that she has anything against motorcycles, she just doesn't care to learn how to ride.

Just a thought.
Steve

I made a mock-up of the graphic I want to put on the side of the tank. The original image was found on google and modified/cleaned up quite a bit. I may still work on it a little more, but it's really close to what I wanted.

A fairly unproductive weekend as far as the bike goes, had a lot of other things to attend to... First up, I tried to salvage the old battery. It 'looks' sealed, but the strip across the top was coaxed back out with a knife and the battery was only about half full of water. Would have been better if I'd had any acid handy, but I refilled it with water and put it on the slow charger overnight. The results weren't spectacular, but it is slightly more usable now. It's putting out enough amperage to light the lights, but not run the starter, however it IS acting as a decent buffer now so I was able to start the bike using my jumper pack and then keep it running on the battery. Couldn't do that before. That means if I can solve the idling issue, I can actually drive it up and down the street with the battery now (and hope it doesn't die on me).

I finally sandblasted and painted the last part -- the chain guard. Ever since I put the chain on that spot has been looking rather naked, so I finally got around to it yesterday. Will let it cure for the week and then bake it in the over next weekend before bolting it on the bike.

I'll try to get some pics of my handywork, but I also added reinforcement to the longer tabs on the side covers. The right side was definitely stressed, it has some cracks going into the front of the cover. I have some 4" black ABS pipe that I had split open and flattened. It's over 1/4" thick and comes in handy when I need some random material. I used the dremel to shape the pieces and then epoxied each one into place. After sitting overnight I hit each spot with the underbody rubber spray like I had already used inside the covers, which covers up the work nicely. Then I wet-sanded the covers and gave them another coat of the copper color. By next weekend that will be dry and ready for me to start experimenting with adding scales along the top edges.

Oh, I also figured out a way to get low pressure into the front forks... I have a 10gal air tank set up with a low pressure gauge for working with the air brush. It wasn't exactly accurate, but I filled the tank until the gauge read 7psi and then used the tank to fill both forks. It's enough to actually spring back up again when I push down, and they're both even. I guess the rest is just seeing how it feels on the road.

And finally, I worked on the motor a bit more. This morning I tried to warm it up so I could get a low idle speed to check the vacuums, but that failed... it's not idling again, so the carbs are going to come back off and I'll do a full tear-down and clean them again. This afternoon after the engine had cooled down again I decided to check the cylinder compression. Now that I think of it, I'm wondering if I should have checked it warm? Ah well. #1 came to just under 115psi and all the others were sitting at 105. Seems a little low, but I'm not sure what it should read when cold? That was just screwing the gauge into the spark plug holes and cranking the starter.

Anyway, I'll see if I can get the carbs back on the bench tomorrow and work on them through the week. Everything else seems decent enough at this point, so hopefully I can find the problem in here somewhere.