• Announcements

    • Bryan Bosch

      JUST IN!   04/24/2018

      HOW TO: 4-STROKE PISTON REPLACEMENT DONE RIGHT!

markbxr400

Members
  • Content count

    170
  • Joined

  • Last visited

Community Reputation

10 Good

About markbxr400

  • Rank
    TT Bronze Member

Profile Information

  • Location
    Texas
  1. Thanks - I'll try going with a leaner pilot jet (Ibelieve stock is a 42, so maybe a 40). I'll also go back and recheck the valves and put in another new plug. One thing I have noticed is gas running out of the float bowl overflow, I am assuming from the million kicks to try to start it, but I'll also pull the float and the make sure it's seating properly. It definitely seems that it is getting way too much gas when kicking it. Sometimes we can drain the float bowl and get it to start. When we pull start it, it also seems like it has to clear the engine of excess fuel.
  2. Oh, and regarding how the bike runs - at first it had a very bad bog, but we kept dropping the needle on the JD jet until we got it leaned back out. Thanks.
  3. We had adjusted the valves about 10 hours prior and had them spot on. It would start fine before he swapped pipes. I had pulled the pilot jet to go get sizes on either side of it. Wasn't able to get a different size from the dealer, but did clean the original (it was actually vey clean when I pulled it out). Any other idaes? Would this pipe tend to cause the bike to pull more, or less fuel on startup (eg., if I were to try and change the pilot jet, should I try larger or smaller)? Thanks again, Mark
  4. My son installed a Yoshimira RS2 pipe with spark arrestor on his 06 YZ250F. We installed the JD main jet and needle, and it runs very well once it's started, however we have to push start the bike now (actually pull it with another bike several hundred feet). It will not start cold with the kick starter. Once warm, he can kick start it all day, so it's just a cold starting problem. It has the stock pilot jet and leak jet. Only thing we've changed is the main. Any ideas? Thank you, Mark
  5. My son just installed a new pipe, and I had the hanging idle issue, even after rejetting. I was very surprised, however, after messing with the fuel screw all day, I went with a richer needle setting (moved the clip down two spots), and it straightened the hanging idle problem right out. Bike still runs great throughout the range. I would have never thought this would have solved it. Thanks! Mark
  6. I just use the Harbor Freight wrenches. Can have all three if you watch for a sale for about $50. They have not let me down in many years of use. JMHO.
  7. My son's 06 has the oil window . . .
  8. Works fine and gives a much better lean angle.
  9. I bought the 05 new early this summer. Have just made 40 hours, with zero issues. Excellent performance, easy to maintain and very reliable.
  10. Would agree, coming off an 96XR250, 03XR400 to the 05KTM450EXC, you get the reliability and durability of the XR, but so much more bike in the way of performance - both power and suspension. Valves are easy to adjust, I change the oil after every 5-10 hours depending on how hard I ride. Many change the oil filters (2) every 2nd or 3rd oil change. I go ahead and change mine with every oil change. E-start is worth it's weight in gold. Good luck.
  11. I'm 47, 6'0", 210lbs. I went from an XR400 to the 450EXC. Great bike. I can ride hard all day, and never feel like I'm fighting the bike. Smooth power delivery, good suspension, very reliable (like your XR). Not for SX, but great in the tight trails.
  12. Join up. I have a very detailed article with pics titled "450EXC Valve Adjustment for Beginners" in the pinned section of Valve Adjustments. Simple job, but takes about 2-3 hours the first time. Other great articles out there as well.
  13. Very simply, valve lash is the clearance between the overhead cams (not on the cam lobe, but the smooth rounded section) and the buckets that hold the shims on top of the valve stem. When the engine is cold, the clearance is set. As the engine heats up, the valve stem grows, so the clearance is needed to accomodate this growth instead of having the valves tighten up. Tight valved don't fully close. Valves transfer heat to the head when they close, because of the metal to metal contact. So, if they don't close all the way, you end up overheating your valves and burning them up (in addition to losing compression). Slightly loose valves are better than slightly tight valves (IMHO), but too loose valves don't open far enough or for the right amount of time, so you don't get full power (not bringing in full fuel/air for compression, or constipating the engine from not enough exhaust. Hope this helps.
  14. I use the PJ1 supertacky. Yes, I spray both sides and the flange face, then work it in with gloves on. I never have dirt inside the intake throat. Whatever works for eachof us works, so probably no wrong answer, except no oil or no filter.