Jump to content


  • Content count

  • Joined

  • Last visited

Community Reputation

214 Excellent

About SoCalMX70

  • Rank
    TT Silver Member

Profile Information

  • Gender
  • Location
  • Interests
    Riding, Guitar

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. SoCalMX70

    Should I replace my top end?

    True story... Today I counted up my orders for this year (maintenance parts, oil, etc) because I've been racing. 41 orders so far... FORTY ONE! I do go a bit overkill with maintenance and keeping things "perfect", but my bike hasn't let me down yet!
  2. SoCalMX70

    Should I replace my top end?

    As long as you're confident in your/your mechanic's work there's nothing to "make sure" of. It's either going to run right or blow up... Just put a new piston in and not worry about taking it apart for another 25-50 hours. Putting this one back in then an hour later replacing it is an unnecessary hassle.
  3. SoCalMX70

    Should I replace my top end?

    After seeing my buddy's piston in an unknown hours YZ that had good compression, just replace it. His was cracked and looked like it would let go any ride, so he got lucky that he did the tear down. Don't let the fatigue get to the point where a crack starts forming... Replace it and get an hour meter. Replace every 25-30 if you race, 50 if you dont. Sound conservative? Probably is, but I'd rather be throwing pistons at my bike every season rather than rebuilding the entire motor. Edit: And I now see your reply about the bottom end. I know it might suck, but just put the extra $100-130 into a new piston and rings and say you have a brand new motor.
  4. SoCalMX70

    YZ250 How's My Idle?

    42 pilot is too small for sea level. fatten that up to a 45 (at LEAST), 1 turn out on AS, set the idle. Shouldn't hang.
  5. SoCalMX70

    YZ250 rear tire choice?

  6. SoCalMX70

    Power Jet #40

    Rainy weekend? It took me 20 minutes. Get in there and do it!
  7. SoCalMX70

    YZ250 2nd to 1st neutral issue?

    Mine does it. I ride moto though so if I hit neutral it was a mistake on my part. Normally the lowest gear I hit is 2nd for inside ruts... Never intentionally go for 1st.
  8. SoCalMX70

    YZ250X Chain Slap Issue.

    Get a TM slider and guide. It'll get a lot quieter.
  9. SoCalMX70

    Pressure plate rubbing? YZ250x

    Exactly how mine looks. Nothing is rubbing.
  10. SoCalMX70

    Power Jet #40

    Raced at Cahuilla Creek MX this weekend. 90 degrees F at 3700'... Didn't touch anything except turning the air screw out another .25. Ran sooooo good! Per my previous post: -50/50 VP110 and Premium pump (91) -48 Pilot (1.25 1.5 turn on air screw), 175 Main, N3CW-3 I must say, I legitimately had smile on my face while I was warming up on the starting line. Every crack of the throttle was SUPER crisp.
  11. SoCalMX70

    YZ250 build and X comparison

  12. SoCalMX70

    Power Jet #40

    Just wanted to confirm my bike was deadly spot on today. First day out with the 40 PJ as well as a needle change and it's easily the best it's ever been. I don't plan on touching a thing. -2800 Feet -70 degrees -Full on moto -50/50 VP110 and Premium pump (91) -48 Pilot (1.25 turn on air screw), 175 Main, N3CW-3
  13. SoCalMX70

    YZ250 build and X comparison

    I can confirm your theory on the 250 head with X CDI... When I purchased my 2016 YZ250X my intentions were off-road/desert only. That quickly changed when a buddy of mine dragged me back out to the track, where I hadnt been in 6 years. Now I've been at an MX track nearly every weekend since late last year. Here are the mods I've done so far: -YZ gearing. 4th and 5th are just bad on the X if all you do is moto. Went to the regular close ratio 3rd through 5th setup. 14/51 final drive. -2010 YZ head. Yamaha slightly decreased compression from 2011 onward on the YZ250 to be better compatible with (shitty) fuels. I decided to go ahead and start with the original pre 2011 design because I'm running 50/50 race gas anyway. It definitely gave the bike a bit more bark and pull. -Powervalve mod. 1 washer removed. This probably made the biggest difference in power delivery, for me. Woke the bike right up! Powervalve opens fully much more immediate and when you expect it to as you're coming off of corners and trying to clear obstacles. -V Force Reed cage. Why not. -Full Bill's Pipes exhaust system. Light, sounds bitchin, and yes, has great power... especially mid range. -Spot on jetting. As of today I had my first ride out with a 40 Power Jet (check out the thread if you haven't). Eliminated a weird rich spot I had a 3/4 throttle. Bike is crisp bottom to top now. I will be watching your progress and taking note of your findings. I'm always down to dig into my bike and experiment more!
  14. SoCalMX70

    How smart does Yamaha look now?

    Their big bikes still need updates. Im guessing 2020. New YZ65 just came out, new YZ85 coming in 2019, 125 and 250 to follow?
  15. SoCalMX70

    YZ250 Timing Thread

    Excellent information! Question for you since we have the same bike... At stock setting, does the stator line/indentation (located approx 7 o'clock) align with the line that is on the CASE? I know this isn't something to be heavily relied on for accuracy. I am still going to do the real measurement (stator vs fww) when the dial gauge comes in. Just curious.