Wow, Kawdude, that's a lot of questions!! I might be able to help with some of them:
- Have never used Eric Gorr's services, but there have been some posts here that have been less than positive (in fact down right venomous). I have used Rick Peterson Motorsports on a CR265 big bore kit raced in the Open Expert National Hare & Hound Series with great results. I know Eric does a lot of work for folks, I just don't have any experience with his service, so can't be much help here.
- On the tranny, I have only had a couple of problems with a tranny, a broken shifting hub on a KX125, and a counter shaft bearing on a KX250 that took out the case. On an older bike, I would replace the counter shaft bearing without hesitation. As long as the other bearings don't have a lot of play (just by feel, as I don't have specs), I would keep the current bearings. Replace all tranny seals, as they are cheap.
- The vibration is caused from crank runout. The stock runout spec is too high, so having your crank trued will take care of the vibration. If you are going to have the crank trued, replace the rod bearing at a minimum, and rod replacement would not hurt if the wallet will allow.
- Here are the steps to installing the crank:
1-Always install the crank bearings in the cases first.
2-Toss the bearings in the freezer (still in the packages to avoid moisture contamination) for about an hour. While you're at it, toss the crank in the freezer as well, as it needs a little longer to get cold.
3-Heat the bearing pockets in the cases with a small propane torch, and the bearings will just drop in place without any convincing. (You can also use a bearing driver, but most folks don't have one in the garage.) On a KX250, you need to install the seals before the bearings, so heating can create a problem. I put a little grease on the inside of the seals so I can tell if I am getting too much heat on the seal, as the grease will begin to liquefy before you hurt the seal.
4-Before you begin the installation, you will need to build a small frame out of 2x6 standing on edge. The intent here is to have a box that will allow the case half to sit on the edges, and allow the shafts that protrude from the bottom to sit down in the middle. Without this type of frame, you will not be able to drop the crank through the first crank bearing. If you can't figure this out, I can measure mine and let you know the size.
5-Once the bearings are dropped in place, heat the inside race, and drop the crank in place. I install the crank in the case half with all of the gears first, and then drop on the other case half in place. As a note, don't heat the inside race until you are ready to install the crank, so just focus on one case half at a time. Also, don't forget to smear on some case seal on the case halves before you drop the crank through the first bearing, as the crank needs to stay cold enough for both bearings, so time is your enemy when dropping the crank in place. Don't use anything else but the real stuff from the motorcycle shop, as everything else will leak. Don?t force the second case half in place, as you will break the shifting hub. Just wiggle the case, and the hub will drop into the bearing. Might even add a little grease to the hub bearing before you start with the crank installation.
6-Once the cases are together, install all bolts finger tight. You MUST tighten the bolts evenly, such that the case is pressed in place all at the same time. Turn each bolt a half turn at a time in a crisscross pattern until everything is tight. A T-handle is preferred for this task. Also, start with the bolts around the crank in a crisscross pattern, as this is wear the resistance will be.
7-Once the cases are together, use a dead blow hammer to relieve the crank by tapping once or twice on the flywheel end of the crank. If you try and turn the crank before you do this, you will find it turns very hard. Afterwards, it turns easily. Also, check the distance between each crank half and the bearing with a feeler gauge. I try and get the crank centered, with even distance on each side. Not sure if this is that important, but it would seem to be a prudent step. You will probably find the crank is not centered. You can move the crank just slightly with your case splitting tool by just pushing on the proper end of the crank with a little pressure. Releive the crank after centering and recheck the distance.
Viola, you?re done.
Finally, on the stator plate, if the crack allows the stator plate to move, it is a problem. If you need one, you have a problem, as the backing plate is not sold seperately. However, I happen to have one in the shop that should work. We would have to check part numbers, as mine is from a 2002, but if it works, I am sure we can work a deal.
Enjoy the rebuild.
Rick
