1981 KZ1000 J-to-K build

I was expecting soft bearing like you see in a car engine, but these things have full ball bearings in them! I pulled everything completely out of the case halves, then hosed the case down with non-chlorinated brake cleaner to remove the oil (this is also what I use as a final prep before paining everything). Then I used masking tape to tape off things like the bearing surfaces that I absolutely didn't want to get in to. After that I was ready to sandblast. I also have a really small gun, so it's easy to control the spray. Mostly it's just a matter of staying away from the side areas that are actually internal once you have the cover in place. Also if you haven't cleaned them off already, you can leave the old gaskets on to protect those surfaces, then clean them up after the sandblasting is done.

My case had a previous factory paint, so I hit it with a few coats of paint stripped before anything else. This tends to also remove most of the baked-on grease, so my sandblasting mostly focused on getting into the tight spots that the stripper didn't clean out. After you finish sandblasting, toss all the masking tape, and hose it down more completely with the brake cleaner. After this, do NOT touch any surface with your fingers that needs paint, you don't want any oils on the surfaces! The case is pretty easy to handle though, with all the exposed areas that don't get paint. Then mask off everything that needs it and start applying your primer/paint.

With the cold weather moving in, I've had to stop to work on my greenhouse again. Got some good quality plastic to cover the roof this year, and just got it closed up yesterday (I even have a proper door this year! ). We were well into the upper 80's this weekend, but they've been hinting at another possible freeze during the week. We're still a ways off from seeing any snow, but my plants are protected now. I'm going to work on some Halloween decorations next weekend, then maybe I can get back to the engine again.

And now another month has gone by, but I finally got it finished up! I lapped the valves last night, which went very smoothly and left a nice surface on the seats, but this got me thinking about your earlier question, swest... And I realized I did NOT actually sandblast the valve seats. I left the valves in place as I was cleaning the head, and didn't take out the valves until I had all the carbon cleaned out of the piston dome. I guess I was thinking ahead there.



Anyway, so I finished cleaning the valves and then hosed down the head to remove the rest of the lapping compound, don't want to leave any of that grit remaining inside the engine. Today I then had to go through all the individual pieces and clean the sand off of everything. It was time-consuming, but required. As you can see in the previous pic, I didn't get the valve seats dried completely, so there was a little surface rust this morning. It wiped off easily though.



Once everything was cleaned up, I broke out the C-clamp again and started reassembling the valves. It took a bit to figure out the technique on the first one, and I found a flat dental pic helped a lot in getting the pieces in position, then it went pretty smoothly until the last one. Of course there always has to be one that's stubborn, but I finally got the pieces to seat in place.

Unfortunately I ran out of daylight, but I'm ready to drop the head onto the engine and then get the cams in place. Guess I should start reading up on how to set the position of the timing chain...

Did you get pics of the seat area. They can't be too wide or too thin.
Steve

I'm not sure what you mean? All the valves are shown above, and all the contact areas in the head look identical to the close-up shot above. I barely had to touch them to get a clean contact surface between the two. It really looks like someone had done some previous work and only rode the bike a little before I got it. I didn't even bother swapping the little rubber cups on the top side of the valve stems because the ones in there looked almost new.

I think what SWEST (please correct me if I am wrong) is referring to is that just because you have what looks like a good seat area on the valves AND head ..... it's not necessarily a good thing. If the seat area is too wide OR too narrow the valve will not seat properly. I do not have the manual in front of me right now but the correct seating area is described in there. If I remember correctly (which is usually NOT the case), There are 2 angles used when CUTTING the valves. Being as how you lapped them, as I did, there probably will not be an issue as you are not removing allot of material. The only thing I recommend is checking the valve clearance AFTER the bearings and cam are in place and torqued. OK now my project questions lol ... Sandblasted my engine crankcase halves, oil pan, outside of cylinder fin area and my fingers lol. Not sure why but the gun kept clogging, hasn't before and used a new bag of medium grit garnet like before. Going to try some glass beads later because I'm not happy with the results for painting. I also got thinking about our previous conversation about NOT baking in my smoker (Good advice about the oils from the meat in the paint) .... the wife is not going to let me do it in the oven SOOOO after a couple of cold ones I thought OK, wrap it in a couple layers of foil OR a roasting bag and then put it in the smoker to bake the paint. I'm not sure if baking the paint is worth it so I am taking your word that it is worth while and worth the time. If you need specs on the valves, please let me know. I want to thank you for all the info and advice you are putting on here. You are saving me and some others allot of money and headaches. Be well, stay warm and be safe.

My thoughts on the matter are that if there had been noticeable wear on the valve seats, the lapping process would have shown an uneven ridge, pock marks in the seat area itself, or something else. Instead what I have is a lapping job that took literally only 2-3 minutes per valve (and a lot of that was fighting with the tool not sticking well to the valve heads) and left a very clean, even surface on all the parts. That's why I mentioned again that I really feel someone has done a recent overhaul on this engine, because the parts I've been working on show signs of new seals and very minimal wear.

I haven't tried using garnet media before, what I have here is regular white quartz sand, I'd guess around 150 grit? The stuff is dirt cheap, it costs me $7 per 100# bag at Home Depot, and has been working well on all the aluminum parts. What I do need to find is something more aggressive that still works in a small gun, which I can use to tackle the chrome pieces, however I may give up on that and pay a local guy to do it for me. The sand has left a nice satin finish on my aluminum pieces though, which the paint seems to take to. And there is a noticeable difference in the feel of the paint after baking. It may be doing nothing more than adding a year's worth of drying time to the paint, but only time will tell if the paint is actually going to stick well after all this work. I've prepped the surfaces as best I can, but I do understand it's still a rattle-can job. On the other hand, 20 years ago I rebuilt a car engine, and when I got the block back from the engine shop (after they cleaned it), I sprayed it with flat-black paint without even cleaning off my fingerprints. That paint job lasted through 15 years, 200k miles, 2 different cars, and countless oil leaks... so I have *some* hope here.

If you still go with the smoker, I might suggest packing stuff around it as a sort of insulation. They're usually so thin that a gust of wind can drop your temps, and you want to hold the temperatures as solid as possible. Also make sure you have a little space around the parts, and they're not touching the walls at all. I don't know if I would trust foil to not leak, plus I don't think you want it touching the soft paint. Maybe you could form the foil to create a 'cave' within the smoker to set the parts inside though? Failing everything else, carefully reassemble the motor, then use the running heat to cure the paint -- For example, the VHT exhaust paint recommends running for 10 minutes, let it cool down, run for 20 minutes, cool down, then run for 30 minutes to finish curing the paint.

For anyone else following along, running the oven cleaner for at least an hour does remove the paint fumes. One weekend I baked some parts on Saturday, ran the over cleaner, then my wife made cookies the next day... not a hint of paint fumes in the cookies and no further smells of paint when using the oven.

Speaking of which, I only have two more pieces left to paint and bake -- the right-hand side covers. And after doing some reading today, it turns out I *need* to finish those pieces because the smaller piece has the timing marks I need to position the crank before I can set the timing chain. Ah well, at least now I know I can go ahead and set the head on the engine so the top end is sealed up.

Wow, bumped to page 6 over the Winter break. I guess some people have heated workspaces and don't have to take breaks.

So it finally warmed up enough to start painting again. I took off today with the ignition housing and the cover plate that has the oil level glass in it, got both sandblasted and painted. Needed to order a new seal for the ignition housing which should be here sometime this week, so with any luck I'll get those pieces assembled on the bike next weekend. When I left it last Fall, I needed the timing marks on he ignition to set the position of the timing chain -- the head has been sitting patiently in the garage all Winter, I just wanted to make sure the pistons were lined up with the timing marks properly before I put the head on. Nothing worse than trying to start an engine with the ignition 180 degrees out!

So I'll have to look over everything, but I think today's work finishes up cleaning and painting of all the major engine pieces. Other than the oil cap and a case bolt, I don't think there's anything else left? Of course now that I've said that, I'm sure I'll find something else.

When I built the bumper for my truck, I found a guy here in town that does heavy-duty sandblasting pretty cheap. I think one of these days I'll collect the pipes, fenders, and chain guard (all the chrome bits) to have him clean up and knock down the chrome so I can lay down a coat of paint on them. On the fenders I'll be coating with the burnt copper color. I'm thinking I will top it off with a few layers of clearcoat, and after that has dried for a week or two I want to experiment with some scales. I'd like to use a light coat of the headlight tinting paint so that the copper color still shows through it, and I think by doing it on top of the clearcoat the scales will sort of 'float'. Plus if I really screw it up, I can sand off the tint and the clear will protect the paint job. If the tinting doesn't work, I'll just stick with using black. Hmm maybe I should also try a sample with the cast iron color, could be an interesting combination.

Anyway, lots still left to do, but I'm trying to recover after a month of being sick... flu and bronchitis which turned to double pneumonia and laryngitis. Yeah that was fun. Luckily I'm starting to feel somewhat decent again, but being on my feet all afternoon really took a toll.

Take it easy. Don't try to dob too much and get a relapse.
Steve

Oh I've been taking it easy for too long. Trying to go out for walks at lunch again, get my body moving again. Ugh.

Anyway, been fighting with some small screws on the ignition and generator. Some little 5x12's that just would not budge. I have one of those tools where you hit the head with a hammer and it spins the screw loose... stripped out half the screws, had to use a dremmel to cut a slot across them and try again. Last night I finally got the rest of them loose, so I'll stop and pick up some stainless replacements tonight. Slapping the generator on the engine should be easy. And I got a shipping notice yesterday for the new seal for the ignition, that should be here Thursday, so I can put that back together this weekend as well, and then start figuring out the head and timing chain. Hopefully soon I'll have the engine all buttoned up and I can leave to tarp off of it.

I am NOT looking forward to the wiring harness....

Glad your back and your weather is improving. I have missed you and your updates. Keep them coming and stay warm, be well, jon

Aw thanks! Glad I'm not the only one reading all this. As you can probably tell, I like to think things out, then over-think them into the ground, through the core, and out the other side into China. I've also been planning out a train layout the last couple years, trying to think out every possibility before I ever lay a single piece of track. Ah well, it's just my nature, and when I don't have time to work on the bike, I think about what else I could do.

I checked out google and found some new images of folks that had painted their tank in VHT burnt copper, which inspired me to try re-touching a test piece again. Sanded it, added a couple fresh coats, then some clearcoat. Man, if the tank turns out looking that good I'm going to be really happy. Laid up against the cast-iron color, oh yeah, I can live with that look. I actually pulled out the tank, I need to start cleaning it up, and I have some putty to finish filling in around the logo screw holes. Get it all nice and smooth, then put down some primer and start working on the first coats of the copper. The stuff doesn't go on perfectly smooth, I seemed to have trouble getting dry-spray spots last year. Could have been too hot, or maybe just the paint, but if I get started putting down the color now, I'll have time to sand and re-spray areas before I actually need the tank. This is one of those paints where you have to wait 7 days between coats, and I'd like to try and get it done while it is still cool outside.

Unfortunately it's cooling down too much. Supposed to be back in the lower 60's this weekend with a high chance of daily rains. Not a good combination for trying to paint anything. But as long as it's not raining, I can get the ignition and generator covers wrapped up, and maybe drop the head in place...

Which brings up more questions (of course). OK so I need to pick up some assembly lube for the top end. And once all the side covers are sealed, I'll be filling the motor with oil. As soon as the cams are in place and I have the top capped off, I believe I should be able to crank the motor with the starter and begin working the oil through the passages. So here's the thing... Should I use assembly lube on the starter gears before I cap off the generator, or will cranking the engine with the starter be enough to get oil onto those pieces? As a side note, does the generator cap area fill up with oil? It will still be some time before the engine will actually get started, I have to clean up the wiring harness and get it fished through the frame, among other things, but I want to get as much of the internal surfaces coated in oil as soon as I can.

Morning, The forks on your 1981 J look identical to mine. Why do you say they are not original. The chrome front fender looks odd as mine is original, plastic and a bit longer. I may PM you after I do some checking and if you don't mind as I am starting issues after my rebuild. Looking good so far and it sounds like you're find all you need on the net. Keep the info coming. jon