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amcgraw

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About amcgraw

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  1. If he's talking about the "modern" KLX250S, then the 300 has a better pipe because of the removable restrictor, or "butt plug" as its often called. There has also been mention of the KLX250S having a cat, but I can't confirm this. Sorry Shrumple, I know I didn't answer your question.
  2. A former Honda mechanic was telling me about a somewhat similar problem when they tried to run the XR400 down there when it first came out. The final drive ratio had to be so high to get the speeds necessary, and it put unexpected loads on some of the engine parts. If I remember correctly, I think he said that they were breaking cranks because of it. Not a 600, but I thought it might be a related issue.
  3. Was it touching, or just melted? If it was above the slip joint between the headpipe and muffler, it may have been left loose, and the gasses leaking out melted the plastic. I know this has happened to a few KLR650s (yes, I said KLR, not KLX).
  4. First check what it's at now. If your bike was rejetted for the pipe, your screw is probably at 2 or 2.5. Take it down to 2 or 1.5 turns and see how it runs. If it was rejetted (richer) for the pipe, then putting a stock (more restrictive) pipe on should make it run rich, and then you're SOL on the test. As you can see in the chart, when you get richer than around 14.5:1, CO shoots way up. I'd guess your bike is running somewhere between 12:1 and 14:1. They probably don't test for NOx where you are, and if so, it wouldn't hurt to lean it out extra (within reason of course). If the bike is popping and running poorly, it's too far.
  5. No problem. It's centered underneath the carb at the front (the engine side). From the side, you will see a cylindrical boss on the carb. The screw (brass) is accessed from the bottom. You will either need a short slotted screwdriver, or you can loosen the head and airbox boots, and rotate the carb around so you can see the screw. To do this, you might also have to remove the throttle cables. Count how many turns it takes to go from where it is, to where it is seated (not too tight). That will give you a refernce point to the stock settings. If you really need it, I can scan a pic out of the service manual later. Do they inspect your bike to see if all the stock emission control equipment is there, or is it just a sniffer test? I guess there isn't really any stock equipment on the 300 though.
  6. Whaaat? You guys have sniffer tests for bikes there? To answer your question, go leaner to reduce CO emissions. Not too lean though, or your HC will go up. Take a look at this plot. It's kind of blurry, but it's the only one I had. The Keihin CVK34 has a pilot screw, which you tighten to lean out the idle mixture. Stock is 2 turns out, or 1.5 turns out for CA bikes.
  7. 1,2,3,4 are the big head bolts. 5,6 are the acorn nuts on the underside of the head. 7,8 are the cylinder acorn nuts (retighten). 9 is the socket head cap screw on the outside. 10,11 are the long M6 bolts by the cam chain, or on a newer one, they hold down the cam chain cover as well. You'll need a crow's foot wrench to torque the acorn nuts.
  8. As far as I know, coasting for long distances is generally discouraged for any shared oil 4-stroke, wet or dry sump. Since the transmission is lubricated with a combination of oil pressure and splash, you're depriving the bushings of a significant amount of the intended lubrication. I have actually come across warnings about this in the owners manuals of wet sump bikes. With that said, most coasting in the dirt probably won't hurt anything since it is likely going to be slow or for a short distance. Any long distance/high speed coasting should be done with the engine running.
  9. ha! pinky sized. check this out (at the bottom): http://www.ckmcgraw.com/afmcgraw/CRF450.htm
  10. Most transmission gears are case hardened. Dependng on the hardening depth, if you remove too much of the hardened surface, it will wear quickly. Common transmission gear case hardening depths range from around 0.4-1.0mm. Also, due to its hardness, it would likely have to be precision ground. I was alluding to a process such as case hardening in my previous post about the disadvantages of machining the forks; however, I'm not positive about what process is used on the forks.
  11. I'm not really concerned about the machining process affecting the fork. I'm not positive about the CRF forks, but I know that others have some sort of coating or treatment that you can see when it wears off. If that is indeed the case with the CRF, the sides of the fork that move the gears would be left coated/treated, but the inside of the fork still rests against the groove on the gear, and wears. The fork clearance is there for a reason, and I doubt that you would be able to fit the smaller L fork on the M3 gear. If you could, it would probably wear quickly, as the specified clearance would be swallowed up. Anything is possible, and if you have the machining capability and the motivation, go for it. I'm sure we would all like to know how it turns out.
  12. Thanks kjlectric. That was what I was afraid of. The M3 and C5 gears have different shift fork groove diameters. 32.94mm on C5 and 33.88mm on M3. I'm not sure what the fork clearance is, but these were likely designed this way so the transmission would only go together one way. The other dimensions of shift forks are also not interchangeable. The R+L forks on the CS are similar, but the C (center) fork on the MS is significantly shorter center to center and has a smaller fork shaft. So you can't swap the forks. Assuming everything else worked, you could take an L fork and machine a larger opening diameter into it, but then it would need whatever hardening/surface treatment was originally used so it wouldn't wear like crazy.
  13. Nice reply kjlectric. If I had done it, it would have just been numbers! I don't mean to be a pest, but did you get to measure the shift fork groove diameter?
  14. Are the shift fork grooves the same diameter? How about the widths of the gears?
  15. Here's the info I can provide. It's not a final answer, but is better than nothing. The spline count and diameter of the 3rd and 5th gears appears to be the same. The gear labeled 9 on the fiche, which is the splined 3rd gear on the mainshaft (M3 in the service manual), has circlip 29 and splined washer 26 on both sides. The gear labeled 15, the splined 5th gear on the countershaft (C5), also has circlip 29 and splined washer 26 on the shift fork side. They're not on the other side like the 3rd gear since the 1st gear sits on a smaller diameter section of the shaft. It has washer 28 instead. The spline count and diameter should be consistent through the whole gear, but this may mean that other features on this side of the gear are not interchangable. According to the service manual, their non-splined mating gears, M5 (14 on fiche) and C3 (10 on fiche) have the same ID. Not sure about their width. As for or the rest, only someone with the gears in hand could tell us if the other features are interchangable. The shift fork groove width, diameter, and location, and the dog dimensions need to be the same on M3 and C5. The overall width and any dog features need to be the same on M5 and C3. There's no spec in the manual for the shift fork claw ID or the gear groove OD. I know that in some transmissions, the shift fork grooves have different diameters, but since C5 is a 20t and M3 is a 17t, I wouldn't be surprised if they were the same.