1981 KZ1000 J-to-K build

As far as getting sand everywhere... it's bound to happen. I didn't even bother trying to tape off any holes, but I also didn't directly blast any internal surfaces. There's one cover bolt on the main case for an oil passage that goes in from one side and about 3/4 of the way through the block -- take that off after the blasting it done, you'll find a ton of sand packed in there. I basically went back and forth between blasting everything with the garden hose and the air hose until there was no sign of any more sand coming from any of the passages. Some of those you can put the air hose right against the block and really blow them out, just make sure you're wearing safety goggles because half the sand will come back towards you!

As for ring compressors, I should be good. I have one, but you can also use hose clamps to get them to pop in. I'll figure something out, and I really have no idea when I'll get to that stage.

I got the oil pan off the other engine today. Scraped out the chunks, hosed it down with brake cleaner, then hit it with the garden hose... that took off enough of the dirt and grease layer for me to get at it with the sand blaster this weekend. Surprisingly the drain plug on this one is about half the size as the other pan, but at least the oil filter assembly fits correctly on this one. At least the messiest part is done, and the last pan didn't take long to sandblast. Nothing to tape but the inside of the filter hole, then paint, let it dry through the week, then bake it the following weekend (if I wait that long).

Oh it occurs to me... DO NOT BAKE YOUR PAINT IN THE SMOKER! Bad idea! Think about the inside of your smoker -- covered in the oils from all the meat. Do you really want that getting into your fresh paint? After I finished baking my parts in the oven, I turned on the oven cleaning cycle for an hour, baked all the remaining smell right out of it.

Took a little over three hours, but I got the other oil pan cleaned and painted, plus I also cleaned and painted the cap that goes over the oil filter. Also sandblasted the oil drain plug which was heavily rusted (just the head, not the threads). The plug for this an is odd -- it has a cup-shaped washer around it, but no type of gasket. I'll probably hit the hardware store and find a thin nylon washer that fits it.

So I figure let the paint sit for at least 48 hours before I try to bake it. In the meantime I noticed the blackened bolts I had picked up for the frame are indeed rusting. That's a shame, the black looked really good. Guess I'll have to pick up some stainless bolts instead.

Stainless would look cool but I bought the plated ones. So it's not stock, I can have my old ones replated. Until then, I can RIDE. :woohoo:
Steve

Just a quick thought on the Stainless Hardware. It will also rust but it takes a bit longer to do so. The only 2 options you really have to really slow the rust down is paint or Chrome, both of which you will have to keep on top of anyways. Just my humble opinion

Yeah these blackened bolts rusted so fast and so badly that I would have had the same results if I'd used raw iron. I'm using the round socket-head bolts in the foot peg plates, found what I needed in stainless, but couldn't find the other bolts in the right lengths so I just grabbed some plated ones. Painting isn't an option because the socket wrench will knock the paint right off the bolt heads. Gun metal black would be the only option because it's a chemical process, but I've never actually worked with the stuff before... maybe some day down the road though.

Decided to go ahead and [strike]back[/strike] bake the oil pan today. Finished it up, re-gooped the gasket, and torqued down the new pan. Everything looks good this time. Also found a fiber washer for oil drain plugs that fits this one nicely.

Here's a comparison shot between the oil pans. The one on the right is the correct one. You can also see the difference in the drain plug holes, even though both pans have enough meat to use the same size plug.


It's starting to look like an engine now. Just need to find a piece of carpet so I can roll it over into its bottom, and get the jugs in place. I think everything else can be attached while the motor is on the bike?


Since the bike is sitting outside, I will have to keep a tarp over the engine for awhile. Have to get the valve head in place, plus all the side caps, before everything is water-tight. Once the engine case is in place, though, it will finally start feeling like I'm working on a motorcycle instead of a random collection of parts. I definitely have to get the engine buttoned up before Winter, but I think I can also make some progress on the electrical too. Maybe, just *maybe* I'll be able to fire it up this year, even though I'm sure it won't be ready to ride.

Damnitdamnitdamnit... Finally got one of those head bolts loose from another block, got it screwed in about 2/3 of the way into my block, and it stuck. I finally used lock-jaw pliers to get it loose from the original block, but it's just not budging now.

Oh yeah, and then there's that through-hole bolt cap on the side of the block... cleaned up the O-ring, screwed it in by hand, then gave it a good twist with the wrench... SNAP ... oh shit. Fortunately the broken part twisted out easily with a screwdriver, so I pulled one off another block and gave it a much gentler twist.

Ugh what a day...

Hit the hardware store on my way home... took awhile to find a matching fine-thread nut for the head bolts, but I got what I needed. Was able to back out the stuck bolt, then did a better job of cleaning out the hole. I soaked the end of the bolt in oil and worked it in and out of the hole a few times before it finally sank to the bottom. Now it's really going to bug me that this bolt is about two threads lower than the others. Not sure how that happened.

I just wonder what I did to the paint on the bottom of the case, with all the twisting while trying to work this bolt? *sigh*

This afternoon my wife helped me get the cylinder head on the engine. I used a pair of 3" hose clamps and rolled the crank so the center two pistons were TDC as a starting point. Once I figured out what I was doing, I got the pistons to drop up into the holes, then moved the hose clamps to the other two pistons. Started having trouble here, but after working the head I finally got the other two pistons into the sleeves. After removing the clamps, I thought the head would sort of drop into place. No such luck. Sprayed the top of the pistons with WD40 and rotated the crank a bit, the pistons were moving freely, but the cylinder head was caught up on something.

After a couple minutes of looking, I found the culprit. The plastic cam chain guide had managed to get caught up and pushed through the hole where the tensioner goes. :ohmy: Not good! It took a bit of rocking, but I get the head pulled back up (and right off all the pistons, of course). Compared the plastic guide to the spare, and couldn't see any differences, but I swapped them out anyway.

This time I rocked the guide towards the front of the motor, and that worked. Dropped the head back down while preparing to get the clamps back on the first pair of pistons, and get hit with a bit of flying metal. Damnit! Snapped a middle ring. (Don't ask me how I snapped the middle ring without damaging the top ring.) Great, ok, prop the head back up out of my way, grab a spare ring from the other motor, get the slot cleaned out of all the small bits of shattered ring, and then put the replacement in place.

After all that, I finally got all the pistons up into place, held the cam chain and rolled the crank... nice and smooth! No problems rolling all the way through a full cycle, so I think I'm good to go, I volunteered my sister to come help load the motor into the frame next weekend. If nothing else is happening, maybe I can get started sandblasting the piece with the cams, but that might take an afternoon by itself to get cleaned up, plus then I wanted to clean up the valves. The very top piece has already been cleaned and painted (it was easy, so it was the first piece I worked on), so that will finish the top end of the engine, then I can get started on the side covers.

I will at least get the motor buttoned up for the Winter, just no telling yet if I'll be able to start it.

It's not much, there's a motor on the bike frame again! Dinged the paint a little, despite using a blanket, but I guess this gives me a chance to see what it takes to do touch-ups.



The camera flash made the cast iron color look lighter than it really is. Eventually I'll get some pics with the bike in full sun so the color shows naturally.

Another major accomplishment today... the bike is back over beside the garage and out of the back yard. I bet my wife is happy. I'll certainly appreciate not having to move it around every time I mow.

Did you disassemble the rear shocks and if so how do they come apart ? I sent you a private message about splitting the engine cases also. I did not want to take up your whole forum with stupid questions. Thanks for sharing.

I was going to reply to your private message, but as I was typing this out I realized there's a lot of good info here that I really wish I'd had a few months ago when I started pulling my case apart, so I'm just going to put it out here in public in case anyone else can also use the info...

Regarding the shocks, no, I didn't even know they come apart. I have a couple sets, so I just picked the ones that felt the stiffest and put them back on the bike... although some day I might get some nice progressives to replace them.

Start with putting the transmission in neutral... you'll want to note the position of things once the case is split. Also check for bolts on both the top and bottom of the case before you start trying to split them.

Really it's not hard, but if the case halves have a good seal that it takes a bit to get them started. It's about the same with getting the oil pan off, you just have to find a corner where you can start pulling the pieces apart without damaging the outer fins or anything else. If your case has the original paper gasket, it gives you a little space to get in there with a fine flat blade. I think I basically started going around the outside of the case, finding offset fins to pry against or other pieces where I could get some leverage, and just kept working it slowly until one of the corners finally started coming loose. Once you get a small gap started then it gets a lot easier to work from there, getting a flat putty knife between the gap to apply a little more leverage. The main thing to always keep in mind is to not apply pressure in such a way that it might damage the mating surfaces.

Once you get the oil pan off, take out the oil pump. When the case halves come apart, keep the case upside-down, and there are four bolts on the center crank cap to remove. Then you can lift out the whole crank (you may need the ring compressor on the outer two pistons). There are positioning pins in some of the bearing, so watch out for those when you remove the crank. Take them all out, because as you clean the case they'll end up falling out anyway.

There are two rods of gears for the transmission. Note that beside the shifter rod there is a disc with a black center, and there should be a notch or painted mark around one edge. You'll want to record the position of that mark so you can put the tranny back in neutral when you reassemble. (The position shown in my manual was off by about 30 degrees, so I had to find it myself.) There are three forks sitting in slots between the gears, two on one rod and one fork on the other. With the transmission in neutral, you should be able to freely spin the output shaft where the chain sprocket goes. Each of the forks has a pin that sits in slots inside the larger center bar. Just look over how things fit together, or take pictures if needed. At this point you can lift out those two clusters of gears from the case. Each of these has what looks like half of a piston ring that fits a slot in the bearings and the top half of the case -- again remove these and set aside or they'll fall out while cleaning.

There are also centering pins between the cases, one in front and one at the rear, and more of these pins around the sides. Some will be loose and others stuck tight. I would highly suggest taking pictures of all the locations where you have these pins so you can get them all back in later. There are different sizes, but they are interchangeable within the same diameters, however one side has a square shoulder and one side is rounded. When you put them back together, the rounded side should be out.

Another thing to watch for, there are one or two black plastic washers between some of the oil passages that run between the case halves. Otherwise you should be done now. You may decide to pull apart the mechanism from the outside of the case that handles gear changes. I pulled mine apart, but I had another unit sitting beside me to reference for putting it all back together again. I wouldn't do it again unless I really had to.

At this point I hit the case halves with some engine degreaser, let it sit, then hosed it down. Then use a putty knife to scrape off the obvious thick layers of grease, and hit it with the degreaser again. I find that with the lower power of my sandblaster, the sand just bounces off these grease layers, so it saves me a lot of time by getting down to bare metal manually.

After you finish painting and baking the pieces, you want to take them outside and hose them down. Spray water into every last channel, nook, and cranny you can find. Sand will be everywhere, and you don't want to leave anything behind. Don't forget to pull off the cap on the side of the case that covers a big oil passage. When you think you have everything clean, spray it down again. I kept going on each piece until I didn't see a single grain of sand coming out of any spots. Shake the pieces dry, blow out water with an air compressor if you have one, then let them sit for at least another day or two before you start putting them back together. You don't want to have any water left inside the case when you add the oil.

Now you're ready to put all the centering pins back into their holes, replace the internal oil passage seals, drop in the pins for the crank and the half-round rings for the transmission bearings. Put the crankshaft back in place, again using ring compressors on the outside two pistons as needed (I tried to wedge mine through without compressors and broke a ring in the process). There is an arrow on the center crank cap that should point towards the front. Make sure you torque down these bolts in order of the numbers marked on the cap... if you forget to torque them, you'll never be able to get to them without splitting your case again! After that, drop the transmission gears back in place, making sure the gears are in their neutral position. All of your surfaces should be oil-free, but if you're using a liquid gasket you'll want to prep the mating surfaces with some 220 sandpaper, very lightly scoring the surfaces without rounding them off. This gives something for the liquid gasket to bite in to. Before actually applying the gasket, you should practice placing the case back together and fitting the forks back into their slots. With everything together you can shift between 1st and neutral, but you have to give the output shaft a good spin to shift up into second gear. Make sure you can shift through the whole range smoothly (keeping in mind there is no oil in there right now so it will be a bit stiff). Once you have verified everything is working properly, put it back in neutral and remove the bottom half. You're now ready to apply your gasket and do the final assembly. Keep your liquid gasket sealer very thin, once finished it will be paper thin but you want to apply enough that it fully covers the surfaces once it squishes out.

At this point you're going to have a pile of several different lengths of bolts for your case halves. The trick to remember (and this has been true of every engine I've worked on) is that when you drop the bolts into the holes, they will ALL be sticking out the same amount regardless of their actual length. For the case halves, they were all sticking up about half an inch. Note that there are a couple bolts on the case where you want to apply more liquid gasket sealer underneath the head (check your manual). Tighten down the bolts loosely by hand, then work them down to full torque in a couple steps. DO NOT OVER-TIGHTEN! These bolts require very little force to reach torque. For mine, it was only 90 inch-pounds or 7.5 foot pounds. I can easily double that by hand, so don't go crazy when you initially seat them.

The oil pan will be the same process. Get the oil pump put back in and torqued, put in the large O-ring around the oil filter hole, and get your gasket in place. Again you will have bolts of various lengths, but they all stick up the same amount when sitting in the correct holes. Torque them down in multiple steps, then let everything sit overnight so the gasket sealer dries. Finish off your oil plug and oil filter assembly, and you're ready to flip the engine back right side up.

Hope that helps, let me know if you need more details about anything...

Thank you so much for the info. Unlike your weather, I am waiting for it to cool down to start the sand blasting and painting. I have not broken into the case yet and your reply was very helpful. Actually I was waiting for your reply before I started tearing the engine apart lol. I have sand blasted the valve train and have the cylinders off but was kind of hesitant to split the case. I was originally going to tape everything up and blast it WITHOUT splitting the case but after seeing where the media ended up on the top end after taping, here I go lol. I would Like to tell you that the rear shocks "according to my manual" cannot be taken apart. I'm not sure I believe that but will let you know as soon as I find out, hopefully without any damage to me or the parts. What liquid gasket did you use on the case ? Thank you again. jon