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About kawamatt2

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  1. kawamatt2

    My XR400 Project

    Nice! Your coming to the darkside.
  2. Maybe. I just like to post opinions based on facts. Namely the pictures i posted recount poor corrosion resistance. What good did either valvesrule or dwight's posts do for the collective knowledge here at thumpertalk? None because they are unproven opinions. I can't say that my opinions hold any more value, but before I speak on an issue I like to have evidence to support it. Again, you reference aluminum frames breaking. I have no doubt this occurs. It would be unrealistic to think such. What I am advocating is that aluminum is just plain better at corrosion resistance than the steel we commonly see bikes of this era. I'm sure if I searched a bit I could find 10 pictures here on this site of kickstand mounts broken off XR's. What the owner sees when this happens is a frame full of rust and corrosion, likely the reason the mount failed in the first place.
  3. Oh really? Any proof to back up your claim that you've seen plenty of aluminum frames broken in just as many pieces as that? I see you live in California. Maybe all the desert racers and dune riders out there break frames from riding hard but I guarantee aluminum frames don't break due to corrosion. "Down tubes broken off the head tube"? Sounds to me like somebody beat the hell out of that bike and either wrecked it or jumped it too hard. I thought we were talking about failure from corrosion here, NOT from severe trauma. Heck even the XR frame doesn't corrode up on the backbone and down tubes. Thanks for your assessment on the poor corrosion resistance of aluminum. I'll be sure to query you the next time I'm evaluating a material for its metallurgical properties. I should mention some resources such as these though. Aluminum Corrosion and Key to Metals. Maybe you could help them with their assessments of its properties. Whats interesting in all this is aluminum does actually corrode very slightly but thats how it achieves its resistance to further degradation. As aluminum is exposed to the atmosphere, almost immediately a thin aluminum oxide layer forms on the surface and prevents further reactions from taking place between the aluminum and the atmosphere or whatever else it comes into contact with. Don't have much to say regarding your claim that USD's are harsh compared to conventional forks. I disagree for the simple reason that upside down forks have sooo much more aftermarket support and tuneability in terms of internals. Personal opinion though. I did not realize this discussion was concerning the ability for atypical rider to discern the difference in steel versus alloy frames? I assume you meant the feel when riding either? This discussion centered on the durability of the two materials. You bet your atypical rider will know somethings up when they do their bi-annual inspection and see holes in the lower steel frame tubes. "All this technology is wonderful but only needed if you race at a high level." Really!? Glad you've decided that all us trail riders are suited for technologies from the 80's. I ride the XR because it is antiquated. Its cheap to maintain and functions, for the most part, exactly the way I desire. My only complaints, as have been evidenced in this thread, are its somewhat poor corrosion resistance.
  4. That is a good question on the WR. I personally never had use for one but I bet it sold like hotcakes. Maybe fuel injection fit is taking place. I can't see Yamaha discontinuing their only midrange offroad motorcycle in the US.
  5. True enough. I can't ration the fact that KTM and Husky still use steel frames except maybe they don't have enough volume sales to justify a complete frame redesign. Their surely enough expensive as all get out now, so more R&D in a new frame is not justified? In fact Yamaha has provided an aluminum frame on their two strokes since 2005. Suzuki does not offer a two stroke bike any longer. According to their website 2008 was the final year. Additionally Honda no longer offers a two stroke. This is all leading to the point that any two stroke dirtbike with a steel frame is likely too old or too low volume to justify the cost to redesign to an aluminum frame. And I would just like to reiterate my main point. The picture below illustrates the fate of the original frame on my 97' XR4. This bike was not abused, washed after every ride, rigorously maintained, and equipped with a skid plate its entire working life. Yet the lower frame tubes still began to rot after 10 years use. Another example of poor corrosion resistance. You would never see this from an aluminum frame. Realistically I know that in the next few years my present XR frame will probably do the same thing despite my best efforts to keep it clean and dry. This will hamper the effective service life of the bike. I'm the sort that likes to keep something forever. If I could keep the XR4 running and functioning the way it is at this moment, for the next 10 years I'd be a truly happy camper. But The frame is made of steel and I know it will eventually rust away.
  6. Wow man, I really think you need a time machine! You must really hate advances in technology! Clearly the aluminum frame is far inferior to the tried and true steel frame. First inverted forks and now aluminum frames:lol: I will reference one issue in regards to your claim of "prone to damage". Frame Rot This issue I feel is reason enough to desire an aluminum frame. I don't know about you but i sure would hate to walk out one day and find rot holes in the bottom of my frame tubes. On the issue of hard to modify: Says who? You? How much modification have you done to the frame on your XR? None? Right! On the issue of rigidity: Did you want a cadillac or old ford truck like ride where the suspension action is overshadowed by frame and body flex? I know I sure don't. I'd rather have a tight bike that relies on designed suspension action to traverse rough terrain. I think maybe you should voice all your concerns to Honda about this modernization of a classic motorcycle that you feel is so unjust. Maybe they will side with you and bring back steel frames, standard forks, and hell, even carbs. (surely the idea of FI ruffles your feathers! right?!) Maybe your onto something here. Screw the engineering, lets time travel right back to the 70's!
  7. kawamatt2

    Jetting Question for the BST40 Crowd

    I am running similar to ATJ except I have a 45 pilot and 150 main. I think main is good but as it warms up the pilot I feel is too big. I am running a KTM version of the carb and I had alot of trouble getting the bike to rev cleanly above about 3k rpm when first installed. I tried main jets from 147.5 to 155 with no effect on the stumble I was having at lower rpms. I then tried both 42.5 and 45 idle jets and the 45 made the low rpm stumble better but did not cure it. I eventually raised the needle one notch from stock (second from the pointy end) and that cured my missing and stumble at 3-4k rpm. Could have been a fluke or maybe I have an air leak but it runs great now if not a little rich in the warmer weather. I think I am going to drop back to the 42.5 pilot in the coming weeks.
  8. This guy is a joke. He stole money from me on another forum and proceeded to disappear when the parts never showed up. He has changed his story with his bikes and his goals more than I've changed clothes. He never had any intention of shoving any engine in any bike. He either changed his name and is still lurking or we will never seen this bozo again.
  9. kawamatt2

    Mikuni BST40 Help please!

    What is your gearing? 95mph is really moving!
  10. kawamatt2

    Mikuni BST40 Help please!

    With my motarded setup and 16/42 gearing I top out at 84. I think though i run out of power at that speed. The wind resistance and high gearing don't let it pull further. Rpm's were like 8000 so i know it had more. Stock bore and compression with many many woods miles!
  11. kawamatt2

    Mikuni BST40 Help please!

    http://www.thumpertalk.com/forum/showpost.php?p=8803919&postcount=88 Check that post about half way down. I had to go with surprisingly large jets although it seems to run great now. I went with ATJ's (Frank's) machined adapter. Contact him in that thread for an adapter. The airbox boot is too short to reach the rear bell on the mikuni carb.
  12. kawamatt2

    My XR400 Project

    Ditto on the running lean with the stock LC4 settings. I ended up with a 45 pilot, needle in the fourth slot from top (raised one notch), and a 150 main. Do you have any detonation with the 10.5 piston? I get some pinging under heavy load in too high of gear.
  13. kawamatt2

    Edison approach to alerantive XR400 carbs

    Add another to the list of carb swaps! I recently stripped the idle adjustment screw on the stock carb for the XR and decided an upgrade was in order. I first contacted ATJ about snagging one of those nice machined rear boot extenders and one of his left over choke assemblies. We made that happen and then i went looking for a carb. I stumbled on a 00' KTM640 version on advrider for $75 shipped. It came with about 10 main jets but they were all 150 and up. Likely way too big for what i needed. It came and looked pretty great for a used deal. Luckily for me it already had the top vent in a workable position and i decided to just make do with the upper bowl vent being on the passenger side. Franks adapter looks real nice! I was slightly concerned about the cable routing. I guess on the KTM's the carb is really close to the engine and there is no frame tubes right about it. Hence their throttle cables come down from the top instead of the front like on the XR. Anyway I put it in there and got out the construction paper to see if i could knock up a bracket to re-use the stock cabling. This is what i thought would work. My XR is a motard and I had a leftover rear disk guard that had been sitting in the closet for a while. It was scavenged. Cable works great now. No return but i'm gone hope i won't need it. Now on to the jetting fiasco. I knew that Frank was running a 145 main jet in his carb. I am at about half the elevation he is and will be using this thing for motard duties so i went with a 147.5 main. Initially i wasn't sure what pilot my KTM carb had in it though i suspected stock which was a 45. My inquisitive nature forced me to try and get it out to verify and likely replace with a 42.5 pilot. The jet had obviously never been removed as it was stuck tight in there. I ended up stripped the head and had to drill and use a screw extractor to remove it. This is the first time i've tried one of these screw extractors but it worked like a charm! So i swapped in the 42.5 pilot and 147.5 main jet with the stock KTM needle in the stock 3rd clip position. I had a devil of a time getting it started that first time and eventually had to turn the fuel screw out nearly 4 turns just to keep it running. Interestingly the bike wouldn't rev up cleanly past about 3k rpm's. It had great response off idle but would just die after about 1/3 throttle. I did notice though that if i pulled the choke out slightly it ran great! This lead me to believe the pilot jet was too small. Strange as it was stock on the Dr650 but i didn't know what else to do. So I ordered a KTM640 stock pilot (45) and swapped it in. Now i am only at about 2-2.5 turns out to get the highest idle but the bike still died a bit at about half throttle. I did some main jet swapping and went all the way up to a 155 thinking maybe that was the problem. It didn't cure me ills. My last step was to adjust the position of the needle height. I raised the needle one clip height to the 4th position from the top and switched back to a 150 main. Now the bike runs great and revs clean through the whole throttle range. No popping on decel and has all the power it ever did. So in summary i finally settled on 45 pilot at 2.5 turns out, stock ktm needle in the 4th position from the top, and 150 main jet. The air jet in the carb bell is stock at 1.2. I am at an average of 400 ft elevation and the temp was ~60 degrees. I think its a bit rich up top so my next change will be to drop back to a 147.5 main to see if anything changes. I find this strange that my bike would require such wildly different jetting than the OP. It is stock with the airbox snorkel removed and the exhaust baffle gutted. To tackle the choke problem i bought one of the short choke knobs off ATJ in hopes that it would work for me. He warned that it could interfere if i used a return cable but it will work for me. It just barely clears my pull cable when engaged. For the upper carb vent I've read that the stock breather/filter is not all that great. I decided to go with a valve cover filter from autozone and a rubber pcv hose to attach it to the carb. Not hooked up yet, just hunting down a hose barb connector. So thats all it took to get this thing on. After putting about 50 miles on it this weekend i can say the most impressive thing is the throttle smoothness. No more bog right off idle and it revs so much cleaner now. Interestingly I think it made the bike sound different too. More "revvy" now i would say. Also it works much better at partial throttle cruise conditions than the stock carb. Where the stock would surge or cut at times, the Mikuni just chugs along. I've never ridden a pumper carb but i would bet this thing gives the same sort of feel.
  14. kawamatt2

    Edison approach to alerantive XR400 carbs

    I doubt you have piston valve contact or the engine would not run at all. I sometimes experience this same symptom. Its like the kick starter gear has jumped a tooth or something as the lever will drop suddenly and make a crack like a gear has broken or is already broken off. I think though that it is the "one-way" gear on the back of the kick start gear. The spring that holds this gear together may get jammed or just not be strong enough to hold the two sides together. I have borrowed a picture of it from the XR650 subforum.
  15. kawamatt2

    XR400-SM or DRZ400SM...with a twist

    I'd do illegal things to snag a set of those shrouds and tank. I would so buy one if these came to the states.