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About Gimper

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  1. Gimper

    06 450 unidentified o-ring

    The forum auto link generator made my link somewhat difficult to see. The ATV diagram is here. In my experience, there have been two identical "dowels" and o-rings, one between the inner clutch cover and the crankcase (this is the one pictured in your post above, and on the YFZ450 parts fiche, and goes at the blue arrow in my picture) and one between the cylinder and the crankcase (which is on the YFZ diagram linked, but not the YZF diagram you posted, and goes at the red arrow, and is the one in question). These are both in the passage from the outlet of the water pump to the water jacket around the cylinder. I put dowel in quotes because they are aluminum and their only purpose is to keep the o-ring that does the actual sealing in place so it doesn't get squished out into the water passage. That's in contrast to the other two case-to-jug dowels, which are steel, and are true locating dowels meant to keep the case and cylinder from shifting in the gasket plane. Interestingly, however, now that I look more closely, it may be that the 06+ bike engine really doesn't have this dowel. On my 250, and on this ATV case (where you can also see the dowel and o-ring in question, second from the left), you can see a shallow recess for the o-ring, and a deeper bore for the dowel machined into the case; there's a good picture of it on this thread as well. When looking at bike specific cases ( 1 2 3), it looks like the case is just machined flat (and in fact it's even flat on the picture I grabbed to draw the arrows on ). I guess they're omitting the o-ring and letting the base gasket do the sealing. Is yours machined with a groove and bore, or is it flat and the opening the raw casting? The 03-05 YZs have the same part number for the base gasket as the ATVs, but the 06-09 YZ base gasket has a different number, which does have a smaller diameter hole and a raised lip there so it looks like that really is the difference. In that case, as long as you have the 06-09 base gasket and your case is flat, I guess you can ignore the manual telling you to install an o-ring as it must be an incorrect carryover in the manual from the 05 bikes.
  2. Gimper

    06 450 unidentified o-ring

    On my 2003 WR250F I found it, somewhat strangely, on the Crankcase Cover diagram---though that somewhat makes sense as it's the same part numbers for the collar and o-ring between the case and the inner clutch cover (this is true on the 450s as well). Interestingly though, you're right---it doesn't show up anywhere on the YZ450F parts fiches. It does, however, appear on the 2006 YFZ450 Water Pump fiche; the motors are the same this year, and I agree with passthru89 that this is the o-ring the manual is referring to.
  3. Gimper

    Wr450 2017 rubbish kickstand

    Is it actually a different spring? The spring on kran's actually looks like it's extended more than Michael's; I suspect you could cut the cam plate off as well and stretch the spring a bit further after cutting/grinding off the nub on the bolt. Edit: looking at the ridge/valley on the stand, I'd wager that it's the same spring, just with the cam tab added on. It looks like kran's is extended just about the length of the cam plate more than Michael's.
  4. Gimper

    Wr450 2017 rubbish kickstand

    Take a grinder and cut off the little nub on the kickstand pivot bolt (the blue arrow). This is what the hook in the link catches on (at the red arrow) and makes the stand want to fold when pressure is taken off of it. Or get a pivot bolt from a US model bike, as I'm guessing you have a non US model.
  5. Gimper

    Vent hoses FCR 39 MX

    FWIW, normal silicone hose is not rated to be fuel compatible. It may work fine, especially in just a vent application, but if you want an OEM look here's the part number I found researching online for the hose in bulk - 95003-07008-60M. It's a Honda part number, but it's all the same slightly pinkish colored hose. There's another part number out there for (if I remember correctly) 3.5mm id hose instead of 4mm for the bowl drain on some carbs, but I just used this for all of the lines on my OEM '03 WR250F carb and it fit perfectly. The part number is for 8 meters, which is more than enough for two bikes, so less than 10 bucks each.
  6. Gimper

    DRZ400Sm Kickstart Install Remarks

    For anyone doing this in the future, an old trick to avoid camming is to put a bit of valve lapping compound on the tip of the bit. It can help an amazing amount.
  7. Well I decided to take the plunge and purchased what looks like a very clean 2009 setup on fleabay. Unfortunately it's missing the thrust washer between the starter gear and the rotor, so I'll be adding that to my OEM parts order ($5 for a washer!), though it does have the one between the gear and the crank. It's also missing the needle bearing, and I'm going to my local bearing supplier on Monday to get as many bearings as possible rather than pay double for OEM; does anybody happen to know the bearing manufacturer's part number for this needle bearing? I'll order the OEM part if not, but again, it's $15 and probably only 8 from a bearing house. I try pretty hard not to be too cheap these days, but $5+ bucks a bearing adds up when you have 10+ to buy. In any case, I'll report back when I know for sure that it all works, but I'm fairly certain at this point that it will.
  8. In case anyone is interested in the failure that brings the topic up, attached are a few pictures. I believe that the starter clutch began binding, which given the off center single point contact of the intermediate starter gear put an axial twisting force onto the starter ring gear. Even though the crank runout was within spec, it would seem that the added pressure caused the needle bearing to wear on the high spots on the crank (opposing sides radially, opposing edges axially). I don't recall what the actual crank runout was, but it was within spec, though at the high end. Given that it was an aftermarket crank (no recollection of what brand though---it's been 5 years since I put it in), that seems pretty standard from what I've read. I'll be checking my new crank before installing it. Note the flat spots on the one-way bearing rollers! Also the crescent wear on the back of the flywheel, which also indicates to me that the crank had enough runout for the rotor to be off-axis enough to wear like that. I quit riding it when it I noticed while warming it up before a ride that it sounded totally normal, but a significantly louder than usual. No crazy knocking or anything, just the usual bearing growl, but noisier. I figured I was going to find main bearings that were shot. In the end it was a stroke of luck, as I found that one of the third gear dogs was cracked the entire way around and must be hanging on by a sliver of intact metal in the middle. I could've been one ride from a total transmission grenade for all I know! (Video of cracked dog)
  9. Does anyone know if a newer flywheel/starter gear/starter clutch(bearing) will fit a 2003 WR250F? I see that they changed the design some through the years, but I suspect that if I got everything from the crank thrust washer out that it would interchange just fine. It looks like the whole one-way bearing design changed in '04, which I'm not against as I believe that's what ultimately caused my failure. The rotor stays the same through '13. It looks like they added an actual thrust washer between the ring gear and the rotor in '06 (and I assume shortened the snout on the ring gear by that amount, thus the new p/n) and otherwise everything is the same through '13. I guess based on the above, I would assume everything from '04-'13 is swapable in the correct combinations, so my real question is if the change from '03-'04 made anything incompatible. Given that the stator itself is the same for '03 and '04, as is the intermediate starter gear that the ring gear meshes with, and although the crank shows a different part number aftermarket pieces are listed as '03+, I'm fairly certain it's a go. But verification from someone who knows never hurts. Not having to find one year specific parts would sure make things easier. Thanks!
  10. Gimper

    Four Stroke Cylinder Head Reconditioning

    This is prescient since I was just thinking about posting about this. Does anybody have recommendations for reconditioning a head in the San Diego area? Or should I ship it off somewhere? Thanks!
  11. Gimper


    1. If you have fork bleeders, just bleed the air after compressing them and you have no need to worry. 3. The 2-stroke advice may have merit. In a 4-stroke? Get it nice and warmed up before riding it hard (I like to let it idle for a few, then go putt for a few, which also gives some time to make sure everything sounds/feels/runs right after putting it back together) then ride it like you stole it for maximum power via optimum ring seal. It says you can do this above, but neglects to tell you that you should. 4. It's probably also good to point out that if you have relatively easy access to Ethanol-free fuel, use it.
  12. My H6M bulb burned out, and they tend to run ~$30 at local shops/online. There are lots of them available from china for a couple of dollars, but I am very suspect of the quality. I had originally seen this post (http://www.thumpertalk.com/topic/1068697-headlight-bulb-switch-h6m-to-h4/) and was thinking about going this route, but decided to check out other bulbs looking for one with a transverse (horizontal) filament rather than an axial filament, and decided on the H3. This is a single filament bulb, but that's all I ran on my bike anyway, being off-road only. The filament is also in virtually the exact same place as the H6M. I can't find much in the way of tech dimensions on an H6M, but measuring with calipers put the filaments in both bulbs right at 17.5-18mm from the seating face. After clipping the High/Low beam wires (but not the ground) I removed the plastic contact piece by pushing it in and tilting it to pop out the tab on one side, then pushed the whole thing out. (No pic but it's pretty self explanatory when looking at it) I saved this piece, and could always hook it back up later to go back to an H6m. Next I cut a little notch in the bulb retainer, opposite the ground tab, and 90º from the two existing slots. The notch is through the bottom face, as well as into the barrel about the depth of the transition radius; a little extra won't hurt. The notch is to clear the wire on the new bulb, which comes out the side. The rear height of the new bulb is about the same as the old one, but because the plastic contact piece is gone, the spring is too short and doesn't press firmly (or barely at all) on the new bulb. I added a nut I had lying around to act as a spacer for the spring to provide proper tension. Anything that's a close fit, and 4-6mm tall should work. Set the bulb in the housing rotated counterclockwise slightly, line up the retainer with the slots, and pull on the wire to rotate the bulb as you rotate the retainer around into place so that the wire stays in the notch cut previously. As for wiring, the ground was left as is, and I was able to push the connector on the bulb through one of the openings on the rubber boot, and added a shielded female spade connector to the supply wire cut from the original connector. Plug it in, wrap in some electrical tape for extra insurance in terms of insulation and retention, and it's good to go. The only "extra" thing needed to change the bulb now would be electrical tape, though you could easily get by without it in a pinch, or rewrap the stuff you take off though it might not be as pretty. Advantages: 55w bulb rather than 35w (see note below) Commonly stocked bulb at auto parts stores $6 instead of $30 for a name brand like Sylvania Other Notes: In the pictures, I had originally put the supply lead through the boot and added the spade connector there, but it proved to be too much to cram under the boot. I cut that one off and made this connection outside of the boot. The OD of the H3 seating face is slightly smaller than the H6M (22.5mm vs 24mm). I though about doing something to center it perfectly, but we're talking a shift from center of .75mm, and when I moved it around in the housing the beam pattern didn't change at all. The new bulb is 55w, though they are available in other wattages (35w and 100w that I've seen). I'm running this on an '03 WR250F which originally came with a 60w H4 bulb in the rectangular housing, so I'm sure there's enough stator power available to run a 55w bulb. It *may* be ever so slightly dimmer at idle than the H6M, but is nice and bright as soon as the RPMs are up over 1200ish. It's definitely significantly brighter than the H6M. In case anyone is interested in the swap to the newer style headlight, all I did was added two bolts through the mounts in the lower triple clamp for the grommets in the light to go over (see picture), and used the stock upper mounting positions. I added ~10mm of spacer onto the adjustment screw to maintain spring tension, as I think the shroud is pointed up just slightly more than intended, and the adjustment screw is right at the end of it's travel to get the light housing adjusted down enough, and the spring free length is too short to maintain tension. When I bought the bike it had no lights for track use, and I was given the newer style light. It looks a little better, but considering that the factory lights are expensive even used, plus the dislike I hear for this style vs. the older square housing H4 lights in terms of output, I don't know that it would be a worthwhile upgrade.
  13. Gimper

    No More Blistered Hands!

    I have the Palm Savers (a similar product, made by Seal Savers), and they are amazing! I haven't personally tried the Palm Protectors, but my riding buddy uses them (after hearing me rave about mine), and he's had only good things to say. I've never had a problem with blisters between my thumb and first finger, only the calluses at the base of my fingers; if you do, the Palm Protector might be better for coverage in that area, but for me I think I like the fact that the Palm Savers are a little less bulky, but like I said, I haven't tried them, so maybe I wouldn't even notice it. In any case, forget tape, these things are where it's at! For the cost of the two rolls of tape and moleskin listed above, they'll last you waaay longer. I've had mine for two or three seasons, and they're just starting to get a bit haggard. Plus they only take a couple of seconds to put on, and you're ready to go, and you can just take them off when you're stopped.