1982 YZ490 trail machine

Discussion in '2 smokers' started by mudmantra, Sep 28, 2013.

  1. mudmantra

    mudmantra Been here awhile

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    That's wild. Where do you get those monsters? Might be just the thing, when the rain gets here. :evil
  2. dhallilama

    dhallilama Long timer

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    i had a plated KX500 that i rode/commuted with daily for about a year, and occasionally for a few years after that. in Los Angeles traffic, it was a pretty damn good bike. way fun, easy to ride and dead reliable with the 60 mile round trip. the fuel consumption wasn't even half bad. with flat track tires it was damn near spectacular for my use.

    my current daily driver Harley vibrates significantly more than the KX did... the YZ490 i had was somewhere in between (also had a plate for a while, though if that plate were run it may have come back as a honda spree... think there'd have been some hot water).

    if vibes are really bad, there are some spiffy composite bars now... hear great things about 'em, though i've never tried them.


    one thing that's been mentioned but i don't feel emphasized enough: an open class 2T can let you relax a bit without having to wring the motor for all its worth and without having to shift much. the YZ490 i had was still one of the best/easiest "trail bikes" i've had to climb hills. just lug on up them without issue (the tread lightly group would like that)... or rip it up and roost. i'm pretty sure that's why i was passed so rarely on my YZ... it wasn't my sick riding skills, it was the rain storm of rocks in my roost that'd knock other riders off :D
  3. Rot Box

    Rot Box Been here awhile

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    Those Terraflex tires are as meaty as it gets! A friend of mine bought one for his DRZ400 a few months ago. What he didn't account for was weight. It's a steel belted radial for crying out loud :eek1 Not a good combo for bikes without a lot of power to begin with imo. That said I'm not sure if a 490 would even notice it back there.
  4. anotherguy

    anotherguy Long timer

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    If ya wanna see how smooth a single can be try House of Balance. It'll never be glass smooth but there is a significant improvement. They've been doing my stuff for decades. Awesome results and service.
  5. dhallilama

    dhallilama Long timer

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    what are their prices like? i had a local guy that used to do balancing for me, but he up and died a few years back... something about being in his 90s.
  6. anotherguy

    anotherguy Long timer

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    For a single you'll need to remove the rod assembly and reassemble the crank w/o rod. Send them everything from big end of the rod up to rings. Have it balanced and reassemble for install. 'Bout $100 or so if you do the dis/reassemble yourself.
  7. KX50002

    KX50002 NooB, my ass

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    I trail ride a KX500 with FMF Gold series pipe, I wouldn't want anything else, definitely not a KDX 200 or similar. I'm a big guy, ride a lot of hills and mud where more power is better, I can always ride up a gear in the tight woods to tame the power a bit. Having enough torque available to spin the earth backwards just feels GOOD to ME :D. As far as what mods to make to the YZ, I'd say a full tank of 32:1 blendzall and a place to ride is all you need!
  8. dynodave

    dynodave Been here awhile

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    32:1 is no good...before it explodes, you'd better get some advice from twin-pooper on the proper ratio for YOUR KX500.

    Also, ask him if you should should be using a KDX auto lube system...due to your trail riding.
  9. anotherguy

    anotherguy Long timer

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    You must be lying or Valentino Rossi's cousin. 'Cause normal people are unable to ride open class bikes in the woods without severe injury or death. TwinSucker will be by to back me up soon.
  10. dynodave

    dynodave Been here awhile

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  11. mudmantra

    mudmantra Been here awhile

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    Cool Machines! :bmwrider What type carburetor do you have on them? Another owner of a 1982 YZ490 said he had good luck with a PJ38, off a Honda CR500. He said it really improved his low end and mid range throttle response. So I started checking out what CR500 owners were doing with their bike. Sounded like a lot of liked the PWK39 better. Although one guy was using a 38PWK airstriker. He said it was perfect for the type of offroad riding he was doing. I don't know if it's true or not, but there was also something said about Service Honda using the 38pwk Airstriker on their CR500. I called Sudco, but couldn't really get any info on how a PWK would work on a YZ490.
  12. anotherguy

    anotherguy Long timer

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    I have experience with the PWK-AS carb. Granted it wasn't on a 490 but the carb has exceptional partial throttle response and fuel metering as well as WFO performance. Took some time to get it right but that's the case with any carb. Sudco should be able to give you a carb close enough to run OK and you fine tune.
  13. mudmantra

    mudmantra Been here awhile

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    Thanks.:beer Just collecting info on the PWK-as carb now, but I think it might be a good future mod. I have the VM38 on the 490 runs just acceptable right now. But It might run better now that I've changed the crankshaft seals. I think it was sipping some gear side oil. It seemed to be running rich, but ran better once it was hot. Normally rich would run worst when hot, but I think once it was hot enough, it was burning the oil from the gear case. This is from my last set of jetting notes. 6F8 Needle R-0 needle jet, 42.5 pilot, 440 Main, 3.5 cutaway, airscrew 1 and 3/4 out. fuel 92 mixed 32:1, needle clip #3 middle runs good.
    Now I tried the clip in #2 and it ran better until 1/2 throttle then worst.
    So I tried the clip in #4 and the motor loaded up and ran bad everywhere.:bluduh So I put the clip back to # 3 and I'll check it again, now that the seal is changed. Any Idea's?
  14. dynodave

    dynodave Been here awhile

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    One is bone stock. One is 38pwk Airstriker. It would work on your YZ (jetted).
  15. dynodave

    dynodave Been here awhile

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    This X 100!
  16. dynodave

    dynodave Been here awhile

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    Ahhhhh!!! Hit right on the nose dhallilama! Your explanation made me go back and read a section of my Super Hunky article:

    [FONT=Arial, Helvetica, sans-serif]FOCUS ON THE GOOD STUFF
    How about this; Compared to a smaller bike, your 500 is:

    [/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Faster[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Properly tuned, has buckets of smooth power[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Has lots more torque[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Is more versatile,[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Is close to or is the same weight[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Is MUCH more durable[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Has more longevity (won't get thrashed as fast)[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Requires a less maintenance[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Initial purchase cost is less[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Cost less to operate on a yearly basis (less parts replacement - more rear tires though)[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Top ends last WAY LONGER[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Holds it's resale value better[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Requires very little clutch use[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Requires very little shifting[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]And can "cover up" your sloppy riding mistakes[/FONT]
    • [FONT=Arial, Helvetica, sans-serif]And, if ridden correctly, it could be more efficient and might cause you to expend less energy riding in the tight than a smaller bike![/FONT]
  17. stainlesscycle

    stainlesscycle Long timer

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    of all the ridiculous posts you've made, this one surprised me the most, and really proves your ignorance.. it seems you are insinuating that achieving land speed records on a bsa bantam is somehow significantly less of a task than say setting a record on a gsxr1000. whether it's a briggs and stratton or the bub streamliner, the difficulty of making ANY combination the fastest is in theory the same. you do realize that right? that's like saying the fastest guy in the 125cc class is somehow less than the guy running the 500cc class. the top speed is significantly different, but the means to the end is the same. it's all relative. by far the most competitive classes in land speed are smaller cc. ....
  18. mudmantra

    mudmantra Been here awhile

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    Thanks :bmwrider. That's good to know. Which carburetor do you think has the smoothest throttle response?
  19. dynodave

    dynodave Been here awhile

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    You're welcome. 38pwk Airstriker.
  20. dynodave

    dynodave Been here awhile

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    Twin-sucker is not ignorant...it's that he knows so much that just isn't so.
    (stolen from Ronald Reagan.)