1982 YZ490 trail machine

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

  1. mudmantra

    mudmantra Been here awhile

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    Thanks Kevin.
    I've got a lot of details to complete to get these machines ready. Plus I'm collecting a lot of good idea's to follow up on and try. I'm closer to getting the YZ465 in the woods first. I might do that when I have the motor a part on yz490.
  2. mudmantra

    mudmantra Been here awhile

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    When I first got the bike it had a Baja design lighting kit on it. Plus a lighting coil. I don't know for sure, but I was told that the lighting coil was from Ricky stator. Might be an old product they don't make any more. At first this bike wouldn't rev, so I reconditioned and rewired another stator. I might use the lighting coil in the future, but for now I'm going lightless. I believe the 1982 YZ490 uses the same stator base as the IT465/490, so I'm pretty sure a lighting coil from the IT465 or 490 would work also. Picture of YZ490 stator with lighting coil.
    [​IMG]
  3. Mr. Carts

    Mr. Carts Been here awhile

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    I installed the 75watt lighting from Ricky Stator in my IT465.

    They said it was a new product when I bought it last month.
  4. mudmantra

    mudmantra Been here awhile

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    Good to know. I didn't see it on their web site. Must be an item you need to call for. From cross checking part numbers, the IT 465/490, YZ465/ 1982 YZ490 and some IT175's all use the same rotor and stator base. So the same lighting coil should work on all of them. In 1983 the CDI magneto was changed on the YZ490. It then remained the same design through the WR500.
  5. mudmantra

    mudmantra Been here awhile

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    Removed engine from frame. Time to get it ready to send. Need to paint the frame and motor. Remove cylinder head, bore at 87mm.
    [​IMG]
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  6. anotherguy

    anotherguy unsympathetic

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    For the YZ you'll need an L31 lighting coil. There's a few places that stock 'em. Stealhy and Electrex are two off the top of my head. $70-80 or so.
  7. mudmantra

    mudmantra Been here awhile

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    Thanks. Always good to know there's electrical parts available for an older bike. Looks like Electrex has almost all the parts to rebuild a stator. Rex's speedshop also has the CDI's for the YZ465/490 and even the newer YZ490/WR500, at a good price. Pretty sure they can rebuild the stator too. I had some problems with the CDI on my YZ490. First it wouldn't consistently spark, then it wouldn't advance. I completely rewired it and it ran great. Then the coil went out. So I replaced it with a low dollar coil, and it's working fine. :1drink When I removed the motor all the bolts look this way. It may mean nothing But I checked them with my multimeter , and the corrosion has them completely insulated. Just to make sure they don't cause a problem, I'll clean all the motor mount holes and replace the bolts.
    [​IMG]
  8. Mr. Carts

    Mr. Carts Been here awhile

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    Yes I called Ricky Stator for a L 31 and the fellow told me that they had a new 75watt lighting coil that was not on there website.

    I also bought the voltage regulator as he said I may burnout bulbs without it.

    Just call them.
  9. mudmantra

    mudmantra Been here awhile

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    I sent the cylinder, cylinder head and new Wiseco piston to Forward Motion. I was told that the wider smoother more better powerband, was the best running for the YZ490. I couldn't find any reviews on big bore 2 strokes with this porting. But I found a lot of 250 and 300's, with the Mo betta porting. Sounded like it added some grunt down lower, with smoother power up to, or past were the old power band ended. The 490 already had loads of grunt, so this sounded like the way to go. I might not need so much low end grunt, that I loop the bike every time I touch the throttle. :evil
  10. anotherguy

    anotherguy unsympathetic

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    lemme know when ya get it back. I'm curious if he's doing the same thing he's always done or are there changes. I'm considering sending my 465 cylinder/head out.
  11. mudmantra

    mudmantra Been here awhile

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    Yeah I'll let you how YZ490 turns out. My YZ465 has a 1980 cylinder, and I had the head done, but I think the ports are stock. below the pipe, it well torque up and over just about anything. 0n the pipe, I have to stay 100 percent focused. All I have to do is blink at the wrong time, and bad things can happen in a hurry. I hear that the 1981 YZ465 porting is a little more controllable, but I haven't tried it. If getting it ported would retain the low end it has, smooth out the mid range hit, and keep the same top end, it would be awesome. Smoothing out the mid range would at least give you a warning that your about to hit warp speed. :evil
  12. Reverend12

    Reverend12 Well there it is..

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    You aren't going to smooth out a YZ490. I had one when they were new. It'll throw a grapefruit size rock a half a mile... <G>:lol3
  13. mudmantra

    mudmantra Been here awhile

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    Well even just a little smoother on the YZ490 would be OK. It's also supposed to run better and be easier to get the jetting sorted out. But I'll find out when my parts come back. I got the jetting sorted out on my YZ465 and it runs great, throttle response is right there. But in a way, it dose kind of feel like I shortened the fuse to the TNT. :eek1 :lol3
  14. anotherguy

    anotherguy unsympathetic

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    You think the 490 has an abrupt delivery you should ride one of these. That is if there are any left in one piece.

    [​IMG]
  15. KX50002

    KX50002 NooB, my ass

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    My dad used to ride one of those. I wish I still had it

    Sent from my SAMSUNG-SGH-I847 using Tapatalk 2
  16. mudmantra

    mudmantra Been here awhile

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    I know where one's at. I think it's still for sale too. The story I got about these things being so dangerous, was the CDI was unstable. It would go to full advance at the odd times, like starting, halfway into a slide, or any other time it could do the most damage to the rider. :eek1
    [​IMG]
  17. anotherguy

    anotherguy unsympathetic

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  18. KX50002

    KX50002 NooB, my ass

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    OK, my dad's was a 75, I also had a 75 TM 100 I think it had like 10 hp at 70,000 prm it was very pipey and hard to ride, I loved it.
    I wish I still had both of them.
  19. mudmantra

    mudmantra Been here awhile

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    Interesting. :bmwrider Have you ordered anything from them? If it's all legit, then they might be the answer for another machine I have.
  20. anotherguy

    anotherguy unsympathetic

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    Yeah I built a supercharged Valkyrie for a guy and at 9.8:1 compression and 7 pounds of boost the advance curve needed adjustment to say the least. They built me a custom plug and play adjustable ignition w/boost sensor (scary drilling a big hole in that plenum) that accessed 10 separate curves depending on manifold pressure. Took some sorting on the dyno but it did a great job. Customer service is good but slow sometimes due to English being a second language on the other end but they helped me sort out a few bugs easily. Oh and delivered from the Czech Republic it cost under $300 w/software. And it did plug right in.

    In fact I'm thinking about one on my RZ350 with a programmable powervalve set-up. Buy with confidence.