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About tk421

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  1. tk421

    Lets see you YZ's

    after playing
  2. tk421

    Why don't Harley riders like me?

    Wildfx, what’s with the burning American flag? You’re a dip [@#$%&*!]. tk
  3. Jetting Q’s, an excellent post!
  4. tk421

    426 riders need your feedback

    Twistagrip651, The mods to the 426 were simple and straightforward, even the YZ timing wasn’t so bad. Initially the mods for mine were: Throttle stop, BK mod, YZ tank/seat, YZ rear fender, Gray wire, Blue wire, YZ header, YZ muffler, YZ timing, and Taffy Jetting. Then came the plug fouling…that sucks! After trying everything possible, I ended up using a fuel conditioner called Fuel On and haven’t fouled a plug since. In fact, after sitting all winter (5 months) ON LAST YEARS FUEL the bike still started! Later on, additional mods were: Mike Dean’s Coil on Plug, Twin Air Filter System, carbon fiber airbox, and aluminum subframe. The starting drill is at first intimidating but after a while becomes second nature and is really easy. I lowered the forks about 10mm and it improved my cornering. My jetting is excellent! Taffy really knows his stuff. His jetting is in my signature. My elevation is 900’. I could use a bigger starter jet someday, but twisting the throttle a few times before starting works well. Good luck in your decision.
  5. I’m not familiar with the 648 Loctite , I’ve used 242, 609, and 262. Blue (242) is removable, Green (609) is for press fits, and Red (262) is for permanent applications. I’d use Red (262) Loctite just to be safe and hope to never have to take it apart again! That stuff is what it says…PERMANENT.
  6. tk421

    03' WR450 problem after cutting throttle block

    major, The TPS sensor is in my opinion your problem (IMO). It is adjustable and can be set up with a Torx wrench and a digital volt/ohm meter. Check the owner’s manual for the correct ohm readings. There will be two: One for throttle closed and one for wide-open throttle. Good luck.
  7. tk421

    03' WR450 problem after cutting throttle block

    major, It's unlikely the jetting would be the problem. Throttle position sensor must now be checked IMO. If not that, disconnect the gray wire. Good luck.
  8. tk421

    520exc vs wr450?

    :D Hey that's a good one!
  9. tk421

    PLEASE HELP ME & MY 2001 WR426!!

    fourstroker, You probably don’t want to hear this but another way is to remove the carb and custom fit your throttle stop so that the slide just clears the throat at wide open throttle. After your throttle stop length has been determined and is reinstalled, the TPS resistance needs to be checked. Good luck.
  10. tk421

    How Long Will It Take YAMAHA???

    For those who need to do this, here is a source for the grinding paste. Lapping Compound
  11. I was sorting through some old boxes the other day and ran across this article in a Trail Bikes magazine. Enjoy! When we first sat down to plan a list of motorcycles to test for this magazine, two bikes went on the “must ride” list. The Kawasaki KDX175, because it’s probably the finest lightweight motorcycle designed, and the Yamaha IT465H. The IT465H had a great world-wide debut at the ISDT event in France, a grueling six day event that totally taxes and wears down any motorcycle ever made. Throughout the whole week Larry Roeseler and Jim Fishback were riding IT465s. We had a good chance to watch their bikes as the week progressed. Our opinion of the bike on Day One remained unaltered as the event continued through its 1000 miles torture test. Of all the motorcycles entered in this motorcycling Olympiad, the Yamaha IT465H seemed to be holding up admirably, coping and attacking terrain with very little effort. While other bikes were losing transmissions, blowing top ends and basically coming unglued from the constant punishment of six consecutive days of hard riding, neither 465 so much as skipped a single beat all week. Five months later when we threw a leg over the IT465 we finally got a chance to find out why the bike worked so well at ISDT. To date it’s the best big bore enduro machine ever to come out of Japan. The most impressive and awesome component of the IT465 is the engine. After six years of big bore enduro bike manufacturing, Yamaha has come up with a combination of powerplant components that are extremely well suited for enduro racing. The IT465 engine is a direct adaption from the YZ465 motocross engine. The motors share a common crank, cumbustion chamber, clutch and bore and stroke measurement. The difference lies in the heavier flywheel on the IT (to run the lights), the different internal gearing (gears are wider, taller and longer), smaller carburetor and more restrictive exhaust pipe (because of the spark arrestor). Where the YZ465 is slightly peaky, and revs very quickly, the IT, thanks mainly to the flywheel and exhaust, has changed the brutal 50 horsepower machine into a cooperative racer. The powerband in long, flowing and gradual-but it still retains a lot of muscle. As you might suspect, the abundance of low-end torque seems to have no basement level. You can almost snap your neck by dropping the clutch at slightly above idle. In one enduro, while plonking at a snail’s pace through a water-melon size rock section, we realized that the bike was going less than 10 mph, yet was content to stay in third gear and still pull strongly. The majority of enduro riding, the “tight stuff” requires precision and control to get through it quickly. The IT465, thanks to its great power-plant, allows you to select lines and directions with the throttle. By keeping the motor in the sub-5000 rpm range, the bike reacts and responds as though it’s driven by an electric motor. Engine response is smooth, strong and never lacking in horsepower. It wasn’t until we’d ridden the IT465H over 400 miles that we realized just how often the bike was ridden at or near half throttle. A friend questioned us about the top end power. We had to admit that we really didn’t know. Not because we weren’t going fast enough to find out-it was just that the bike was so cooperative in low end power that we never really tapped whatever lies at wide open throttle. The only problem we had adapting to the engine was in tight corners. The heavy flywheel carries a lot of weight and enertia, and one gets used to depending on the engine to be always running. But sometimes, especially during hard braking, the engine will die. Pulling the clutch in for tight corners solved the problem for us, but it was still a little while before we stopped relying on the engine always being there and constantly pumping out the torque. It seems as reliable as the sun-but on occasion the rider gets so confident that the motor will always be there that it comes as a surprise when it dies. If the gearbox ratios have any flaws in progression or spacing, you’d be hard pressed to find them. The engine pumps so strongly that it could easily cover any blemishes in gear ratios. Although on a few occasions we found ourselves slipping the clutch when moving from a near dead stop in second or third gear, for the most part you could pick a gear and stay in it-for miles. The handling of the machine isn’t superb-but it isn’t bad either. The bike handles well, but it never lets you forget about the weight. Yamaha’s spec chart claims a dry weight (minus any oils or gasoline) of 248 pounds, a hefty bit more than the IT250. When you add in fork oil, gearbox oil and gasoline, the bike will tip the scales at over 270 pounds. That’s a weight to respect, and it becomes evident in extremely tight sections when the rider is throwing the bike around-or picking it up after a mistake. While it’s a small price to pay for the horsepower advantage, you’d better be strong if your going to muscle this Yamaha around. Fortunately it has brakes that are very capable of stopping the weight. The front wheel has a dual leading shoe system-almost twice as effective as traditional drum brakes. It’s hard to adapt to that much brake-we went over the bars a couple of times because we squeezed too hard on the front brake. Once it gets slightly glazed and the rider adapts, you’ll forever disdain any other brake. It’s more than adequate when it comes to hauling down to a crawl. The front brake’s flawless performance compensates for the rear brake. Because of the rear wheel quick change system (requiring only 5 seconds to remove) the back brake is not a floating brake system and uses the swingarm as a backing plate. The brake is interrupted by suspension movement, and will chatter and lock when you’re looking for the same precision that the front offers. You can adapt, but it would be nice if the rear worked as well as the front. Yamaha has used its adjustable suspension on the IT465H. The front forks are air/oil and spring units which allow great versatility in presure and oil levels. The rear shock has 24 different damping settings and a large range of spring preload adjustment. The suspension, depending on where and how fast you ride, can be good or “almost good.” Woods riders will find the suspension very close to being dialed in. A little extra oil and air in the forks will keep most “A” riders happy about the front. Seeting the adjustable monoshock damper in one of the light settings, and using the Yamaha accessory firm shock spring will reward most woods riders with good suspension. The shock’s 24 position damping adjuster can be dialed in with a little seat of the pants tuning and a couple hours of fiddling. Most riders who use the bike for weekend fun will most likely be very satisfied with the standard suspension. Desert enduro racers, or the ultrafast woods racers who prefer Its will want a little more from the 465’s suspension. We found a very good suspension system offered by White Brother Cycle Specialties. Their fork kit and shock modification will upgrade and refine the IT465H to put it on par with any other National Enduro winning mount. With suspension increased from 10.6 to 11.8 inches travel the bike is a little tall and can be a handful in tight sections where you’re always putting your foot out to steady yourself. It’s a small compromise considering how well the suspension works on other portions of race courses. The modified shock is tamed down, through the use of different damping washers in the internal shock body, and a unique cross-over dual spring system. The front forks received a complete damper rod and spring fork kit, which increased travel (again to 11.8 inches), speeded up the reaction of the forks and eliminated the harsh bottoming-out feeling. The only other change we made to our test mount was the addition of different handlebars. These were a personal preference. We felt the stock bars were too “sweepy” and too high. Even still, our total investment of $270 in accessories resulted in a big bore enduro machine capable of winning any enduro in the country. Towards the end of our tests we realized that many of these Its will never see an enduro event. They’ll be ridden out in the back hills by weekend trailriders. It’s going to be “the bike” of big bore enthusiasts. The world is getting around about the IT465H. People are discovering that it climbs any hill you can find, regardless of the presence or absence of a trail. It stops well, handles handsomely despite it’s weight and for most people has enough adjustments in its suspension system to make for a plush day’s ride. The IT465H is going to be a very successful enduro machine and even more popular weekend playbike. The combination of abundant horsepower, good all around suspension, nice handling and Yamaha reliability will result in brisk IT465 sales. And why not? It’s a great racing mount and an even better weekend warrior.
  12. tk421

    Changing cam timing to a YZF spec

    Watch out for the bearing retainers (they can easily fall into the engine) , and be careful not to over tighten the camshaft caps. I used these illustrations when I changed mine to YZ timing.
  13. tk421

    WR400F Starting/Jetting Problems

    This procedure is similar to a prime button on a lawn mower or snow blower: When the bike is cold, try giving the throttle one or two full turns before going through “The starting drill”. Be careful not to get too throttle happy or it will flood. And only do this when the bike is cold.
  14. tk421

    Need help after Mod's

    I noticed my accelerator pump is somewhat prone to fail if the bike is stored for a period of time. You may want to check yours.