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About RocketScientist

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  1. RocketScientist

    new rebuild and start shaft whining...

    I just had the exact problem with my 08 YZ450F. I had one of my motors torn apart and sitting in the shop for about a year. It got dirty from sitting out and I parts washed everything and put it back together. After hearing the massive noise from the kicker when it was running, I took kicker gears out and didn't see anything wrong. I put it back together and the same thing happened. Then I searched for the noisy kicker on thumpertalk and found this thread. Thanks to rmx, I took my kicker parts out and soaked them in oil. Put it back in and problem solved. Runs like budda. It was just dry from the parts. I just wanted to say thanks to rmx and this forum for saving me the headache.
  2. RocketScientist

    what would you do ....

    It will be a gas guzzler, and dealing with premix. I would still go 500 2-smoke cause I'm sick. I'd opt for a larger tank for the street.
  3. RocketScientist

    Tardin out the 06 450 and need advice

    Oh I forgot. I suggest getting an aftermarket stator that will drive lights. As far as headlights, I like the UFO headlight assembly. I got the one that uses the 12v indoor lights that you can get from a hardware store. You can get an hydraulic switch that connects to your break master cylinder to operate the brake light.
  4. RocketScientist

    Tardin out the 06 450 and need advice

    For low budget conversion, check out cyclegear.com and search for supermoto. click the warp 9 wheel kit. It comes with a large front rotor and the bracket to offset your front caliper. You can buy the large caliper if you want, but I have the large caliper and think the front break is too grabby. Get some tubes and tires and maybe a large front sprocket and you're done. For large budget, you will want to check out Talon hubs, Excel wheels, heavy duty spokes. You can get both your front and rear suspension lowered for quicker transition in the turnes. Tires will typically be a 120/17 front and a 150/17 rear.
  5. RocketScientist


    I wear the Joe Rocket Supermoto jacket. I don't wear it because it says supermoto on it. It just happens to be the most comfortable jacket I own (I have 8 jackets and two of them are the Joe Rocket Supermoto). It is perferated and stays very cool in the summer. It is pricy, but the best in comfort and a great warm weather jacket. I never ride without a jacket helmet and gloves.
  6. RocketScientist

    Valve Gaps - whats normal?

    I take it that you are missing a hand or leg from a catastrophic engine explosion from your worn valves. LOL. Sorry, couldn't help myself.
  7. RocketScientist

    Rekluse and starting issues?

    This thread is hilarious. I have a YZ450F with a rekluse and was running a high compression piston. Oh, by the way, I welded up the neutral detent so it is always in gear. It for sure is harder to kick, but I can start it. Ok, I’m done laughing. Now here is the trick. Most 450's regardless of the make will only spin the crank shaft 2 turns with every full kick. This means that the engine goes through only 1 complete four stroke cycle with 1 kick. If you start the kick on the compression cycle (where the kicker feels stiff), you must rely on the engine's inertia to get through the next compression cycle. The resistance from the compression cycle combined with the drag from the rekluse can slow the engine down enough to prevent it from starting. The solution is to push the kicker until you get just past the compression stroke (right where you feel the kicker go soft). Raise the kicker up and give a full kick. The bike should start right up, because you are forcing the engine through the compression stroke when your foot reaches the bottom of the kick.
  8. RocketScientist

    YZ top end gearing?

    I get a little more power. I had high compression with stock bore and it was very difficult to start. I went through two sets of boots and one broken kick lever before changing to Athena big bore. The Athena is a 2 ring design. I went to Total Seal and had a top ring built for the piston. It is a two part top ring in which the gaps overlap each other. So far it is working good. My 04 has port and polish. Ceramic coating on the exhaust port, combustion chamber and piston crown. E-Line stator for lights. Rekluse clutch that I have modified to fit a steel plate against the clutch hub. This reduces wear. Hinson clutch hub. Few tungsten carbide bearings in the Rekluse to make it grabbier. 5-speed WR tranny. I have an 08 that I am building with a stroker crank and the big bore cylinder. I just put the crank in this morning. This combinaton will make the bike around 500cc. The Hot-Rods stroker crank costs about half of what the Athena big bore kit does, but Hot-Rods doesen't make a stroker crank for the 03-05 YZ450. If they did, my 04 would be 500cc.
  9. RocketScientist


    Ok, if it is dumping that much out, check the radiator cap. The cap has 2 seals on it. The smaller inner seal should not be damaged in any way. The inner seal is spring loaded and should be able to get contact with the surface inside the radiator fill hole. The radiator cap is designed to hold pressure on the coolant system. The extra pressure raises the boiling point of the coolant. If the coolant does not pressurize, it is guaranteed that the coolant will boil and dump out. Most MX bikes have the same size and pressure rated radiator caps. Try borrowing one from another bike.
  10. RocketScientist


    Don't worry, it's normal. When the coolant heats up, it expands and takes up more room. If you fill it up full when it's cold, the bike will spit out the excess as it gets warm. Most vehicles have a tank to catch the excess (called an overflow tank). When the engine cools, the coolant gets sucked back into the radiator. MX bikes don't have an overflow tank and will spit out the excess. The rediator doesn't have to be 100% full but you should be able to see coolant as you look in. Just check it every once in a while. Remember, the bike doesn't have a radiator fan. This means if you stop and let it idle for long periods of time, the engine will overheat. You must keep moving to keep airflow through the radiator.
  11. RocketScientist

    08 YZ450F - How much did you pay?

    6K OTD at a Tucson Dealership. Told them that I wouldn't pay a penny more.
  12. RocketScientist

    YZ top end gearing?

    I said, my 04 is a 5-speed.
  13. RocketScientist

    YZ top end gearing?

    I have an '04 yz450 5-speed over bored to 478. I run 16-45. No speedo and no idea how fast it goes. Don't care either. I could only find one company to make a 16 tooth front (SunStar). The sprocket is so big, I can't fit a sprocket guard. If I loose the chain, the case would be trash.
  14. RocketScientist

    06' YZ450F cutting out!

    Valve clearance ok, but did you check the valve timing?
  15. RocketScientist

    06' YZ450F cutting out!

    If this happened right after the top end was rebuilt, I would take off the valve cover and double check the valve train. Double check valve clearance and cam timing. If you are 100% it is correct, then it is most likely the carb. If you have ever taken the needle out of the carb, you may want to check it for damage. They are pretty easy to bend and scratch.