Dewalt 18v impact driver is what I use and I've had no problems so far.

Well I am certainly glad I took the long way around cleaning the mouse crap out of the lower end. I removed all the remaining stuff from the right hand case with the exception of the kickstart spindle since it would not come out anyway. The manual shown the cases to be split from the right side, since I was having such a hard time trying it from the left side. This was with some of the kick start gears and some of the shifter mechanism intact, I removed the shift lever rod, but it would separate a little but not all the way around. This had me concerned that the right side was the way to go since there were things that may be covered that were needed to be removed before everything could separate, so off to the right side I went.
Removed everything that seemed needed according the Haynes book I had, set up the puller and ran into the same problem as the left side. Thought maybe it is the shift drum needed the detent removed, did that, no change. Looking at the book, my detent looked like it was missing the spring and pin. All illustrations shown 3 or 4 different kinds and all... so it seemed... one stacked behind the other. Mine looked like it had a bullet tip that did not move. So I figured, what the heck pound the end with a dead bow soft hammer, as see what gives. Well the stuck pin cam loose, the spring was there but was contained within the pin! go figure. Well that was good to find out. could have gone bad otherwise. So good to have found that but the cases still will not separate any more than before. All along I have been looking over the cases numerous times, starting when I was trying to pull the left side, looking for something I must have overlooked. Same thing with the right side attempt. Figured the shifter drum was the culprit, after all what else could it be? I removed all the screws, loosed EVERY one of them and took them out. So out came the channel locks to attempt the draw or try to draw the drum out a little, if possible, to see if it was going to draw out. All the other shafts were headed the right direction. The drum will not move. Froze in place. A few tries got it to move a little, and wiggled it on out. Another good thing to find out.

While wrangling the case around trying to get the thing loose, my eye happened to catch something that did not look right... a screw head... hidden?? How out of how many times I went over the case, could I have missed it!! I thought it was the first time seeing it so I was prepared to crank it out, but I already had it loose, just never took it out. After it was out the cases came apart sooo easy.

The cases really had a lot of gunk in the bottom, sludge galore, the gears all looked a lot better than expected given all the hard bits mixed in the sludge in the bottom. The crank shaft area really had a LOT of crap in there. 

I will replace all the seals along with one crank bearing that seized in the past month, go figure. When I pulled the jug the piston moved quite readily with the crank rotation. Never suspected an issue to happen there. Upon removal the bearing have enough rust to be an issue with any bearing.
  

You'll be happy you pulled it apart in the end, can sleep easy. When i was young--very young-- i got the outer case of a bsa gearbox without removing a hidden screw or bolt tucked in behind where i least expected. Wasn't a good day.

I have been trying to confirm the part number for the crank bearing I need. Partzilla is no help. I thought on an earlier search the part number was 93306-20633-00. I look up the bearing by part number, and the drop down list shows the number is good for my bike. I click on the link for my bike in that drop down list and look up the bearing there, is lists the part number as 93306-30630-00. I thought that was for the MX 360. What gives?!

Progress update.
I got a lot of the parts in. The bike has been apart for a while now, with everything cleaned up with a safety kleen parts washer, I stated to get some things back together. First thing was the shocks, the ones the bike came with were in sorrowful shape. I was so excited to find shocks that would fit and at a reasonable price and got them on with minimal fuss. A tight fit in the places they go into, but I imagine better tight than sloppy. The metal sleeves that go in the rubber grommet fit it like it was made for it. I think the prior owner may have set the wrong bushings in since it looked like everything was flush with the metal eye of the old shocks.

 
 


The fiasco I created for myself with the lower tubes of the front forks has been remedied with the help of Adguy. I have 2 new to me tubes, new seals, and finally after buying dust seals perhaps 40 years ago, finally got them installed. A milestone for me, long time waiting.

  

 

While I was eyeing up the process needed to install the new bearing the crankshaft needs, in handling the case, the kickstart return spring and sleeve falls out. Bummer. Upon a closer look, I am gad it did. It appears the sleeve got mangled somehow there is a folded piece of metal that don't seem right

  

I figured it was not supped to be folded up that way so i straightened it out a bit closer to its original shape, but if I keep it, it needs more work. There is a clip on the inside that looks as if the end of the spring is supposed to go there, but still not lined up well enough yet.
I looked up the part on Partzilla and got the number since Partzilla does not have it. There are 2 available on eBay One has a clear pic of all sides and it is not the same as the original. It may not need to be the same since the mangled end was folded up in so far it did nothing anyway The NOS part doesn't even have the clip that was bent. I seen no superceded part numbers either.

  

Well that is were I am at so far. any input is welcome that will help keep me on track, and will be greatly appreciated.

It has been a while.....Been plugging away at going deeper into the rebuild of my ride, as I finally succeeded in splitting the case, and while removing the old gasket material, I found an issue that tells me of the skills of the previous owner. Somehow the case managed to get dinged on the inside face of the gasket surface, where the cylinder meets the case.

 

 I am glad I took this thing apart to the extent I have; this seems like it could have leaked a bit. I carefully used a fine cut flat file to even out the surface; the pic shows the remnant of the high spot created by the dings of the prior owner. The red outline shows the ridge that was filed down, the rest of the scratched area are superficial marks.

  

Pardon if I repeat some things, there are things I had to come back to since more issues revealed themselves. For example, I thought the main bearing issue was resolved. Bought the new bearing for one side, did the oven and freezer trick, and the bearing dropped right in with a little series of light taps around the outer ring with a wood dowel and small hammer, just to get it started, then it dropped in the rest of the way all by itself. I did tap it a time or 2 again to make sure it sounded like it seated in at the bottom. As I was getting myself psyched up for getting the crank in, I checked the original bearing one last time to see if it was running smoothly as it was before, since while I was cleaning all the crap out with the parts washer, there was a sticky spot in the bearing that I thought I had flushed out. The spot came back. I did not want to chance it, so another bearing was ordered. That one went right in too, just like the first one. Thinking this through a little more I figured I better get the transmission together in and troubleshoot it before the complicated process of installing the crank. Getting the case halves together without the crank was a feat in its own. The first time. I noticed I had my fingers all over the gasket surface that would be covered in Yamabond when the time came, so practice seemed like a good idea. On separating the halves again, I seen the shifter drum did not want to come free like it should. It wanted to come up for the ride too, so I kept it down with a thumb while trying to wrangle the half of the case off. I have gotten familiar with how the drum goes in and the forks line up, so I take out the drum and noticed a bunch of plier tooth marks on each side at the top of the shift drum assembly. Yup they were raised burrs. So, I wrapped the drum in a paper towel, since it was oiled, and took my file to it to knock off the burrs. This part was not kept in a bearing journal, so I did not sweat it since it was not a wear surface. After that the case halves separated as almost as easily as going together. The kick start was another thing that had its problems I brought this up before, so I will keep it as a "refresher".

I was hoping not to have to mess with it, since in reading here, there was a question how much preload does the spring need? Well, moving the case around the way I have been made sure I needed to find that out for myself…. The kickstart shaft and spring fall to the floor. Oh well…. I am kinda glad it did that too. Something did not look right about the metal thing on the inside of the spring retainer.

  

I bent the one part out to the point I thought it was supposed to be. I looked online for a new one to confirm if the idea was correct and all the pics have nothing to show on that side of the retainer. 

  

Here is what I ended up with a little time spent and it actually worked. I see that it preloaded the spring, so there is no guesswork needed. It’s not the prettiest thing but it does keep the spring in place, and when I used pliers to mimic what the kickstart did, it returned to the slot it came from. While I was including this in the practice run of assembling the case halves without the crank, the loading of the spring with the kickstart shaft upon disassembly revealed that the part that I straightened folded back up like before. With that, I felt I had nothing to lose, since the replacement does not have the clip, I broke it off at the bend and tried it again, and it worked fine without it.

Other times I worked on the rear wheel. Since the front end had issues, no need to find out the hard way that the rear does too, so apart it comes. I already had ordered the new shoes when I ordered the front shoes. Upon taking out the brake hub, one of the liners fell to the floor without the shoe. Now I see the reason for always getting new shoes for these older bikes.

   

On top of that, for some reason one of the bearing surfaces of the cam had been filed on. It looked pretty bad, on top of that there was no shim between that cam and the plate, besides being dry as a bone. At the time all I wanted was to find a shim washer for the thing, grease it up, set the new shoes on and reassemble the drum.


 


While reassembling the drum, before getting to the rear tire replacement that was found to be dry rotted in places too, the brake cam lever would not go all the way onto the brake cam. I looked, checked, spread the lever open as much as I dared, but it refused to go on no farther than before. Before I took it apart, the bolt that held it on wasn’t even over the groove intended for the bolt. Then I realized- the brake lever was only on the end, the torque of the brake pedal twisted the very end of the cam, so the serrations that keep the brake cam lever from spinning had turned out of alignment with the serrations on the other side of the bolt groove. (That may fail over time!!!) So, I got another one off eBay. That solved the crappy file job the old one had, and the brake lever slid right on like nobody’s business. THAT problem solved.

 I took my cylinder to a machine shop I just found out about. He has Saturday hours so Shown him what I had. I was concerned about the ring gap It was huge and he agreed. He looked at the piston and says the piston has a lot of wear as the ring did too He checked the bore and it is 70.6mm at the top and bottom where there was no wear. He strongly suggested a rebore, so I ordered a 4th over Wiseco piston, rings and upper bearing. Now I need o get it over to him to do the deed. He will chamfer the ports too. I seen the condition the ports were as they are now an said the corners were way too sharp, surprised the rings didn’t snag.


One last thing I found. I cleaned all the crap out of the reed block assembly after I removed the reeds. Hot water, Dawn dishwashing and hand drying, careful hand drying. I just assembled the reeds to the block and find that the reeds do not set tight to the block. I took it apart and flipped the reeds over, the same thing. I am pretty sure these are supposed to be tight???

This one I could really use some help on!


  

Last week while I was sizing everything up, doing test runs, of assembling the cases with out the crank, I found out two things, one great, one not so good. The great one is that the keyway for the rotor if you may remember, is in really bad shape from the nut being loose and the rotor evidently somehow managed to rattle around enough to do a number on both the crank shaft and the interior of the rotor. Just for the heck of it since it is real simple to check things while the crank is out, I stuck the new woodruff key in the slot of the crank. It was reluctant to go in but seemed stable on its own. It did look like it did not go in all the way so I carefully used a pair of pliers to press it the rest of the way in, since I inspected the slot and it appeared there was nothing keeping it from going all the way in. Well it did and boy was it tight, so slop at all. I cleaned the keyway slot in the rotor and put it on and it went on real snug. A major concern now put away.

 

Since the nuts on the crank for the drive gear and the clutch basket where almost impossible to remove, I checked the nuts on each respective shaft to see how they go on. The clutch nut spun on with out any issue at all. Should not be a problem for the install. Trying the nut for the crank, it only goes on about halfway then gets real tight, so I can't run it up any more by hand. Looking at the threads, they appears to be good except there is a area where the threads are marred, but the nut gets tight even before the nut gets there. I plan to remedy this by using a thread die to run up on the end to clean up anything that is making it difficult to run the nut up and chase out the marred threads as well..

 

 

This weekend since the motor has been on hold because of the holiday and the shop where I hoped to get the die for the crank threads isn't open 'til tomorrow, I dove deeper into the rear wheel, changing out the tire. That was an interesting mess.I got the bead broke loose from the rim after I removed the valve stem, and the nuts from rim locks. The locks acted like they were seized in place, so with a block of wood and a hammer, I attempted to move them around to break them free. They appeared as if they were "wanting" to move, but very limited. So I, being a carpenter by trade, and could not get the rim locks to give up so the tire could be removed, I did what any self respecting carpenter would do, cut it off with my circular saw. Worked like a charm. Smelly, trashed a blade, but the tire was off, but the beads were still on.

 

That revealed why the rim locks would not come off. Both rim locks, on one side somehow managed to separate the rubber from the metal backer and the metal part of the tire lock was wedged under the bead, between the bead and the rim. Making it pretty much impossible to loosen the rim locks to remove the tire any other way. I think the original owner in his quest to build the ultimate machine put a wider than normal tire on the rear which I think mad the bead do things it was not meant to do. Before I started to remove the tire, I was wondering why the rim lock threaded portion was leaning to one side, that was why I believe. Also the rim locks did not do their intended job of keeping the tire from spinning on the rim. I found the tire liner bunched up on one side of the valve stem.