That's Right, This Thread is About a PW50

Discussion in 'Thumpers' started by brentde3, May 15, 2010.

  1. brentde3

    brentde3 Should be outside

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    Hey folks,

    I read with great interest all of the various and sundry "I got this sweet old/new bike, now look what I'm going to do with it!" threads, and I wish I had one to contribute. Money and a slightly more important trip to plan has my 76 R90/6 project on hold, and the KLR is running fine.

    And then along comes this:
    [​IMG]
    It's a 1993 Yamaha PW50. A friend of ours had it lying around and offered it to us for $100. You just can't say no to that! It runs and rides just fine:
    [​IMG]
    Even fun for big kids too:
    [​IMG]:D
    But anyone with tools knows that it's hard to resist working on a bike. After all, it did take ten kicks to get her going. Might as well try to get that number down, right?
    [​IMG]
    My son is five and this will eventually be his bike. My daughter is officially fifteen-days-old today :clap:D:clapand I'm pretty sure that she'll want to ride it too. I've told my son that he can't ride a motorcycle until he learns to ride his bicycle without training wheels. So, in the meantime, we're going to "work on the bike." He's decided that he wants to "take it down to the frame." I think this is an awesome summer project (cheap too), so, here we go.

    Hey, a PW50 is a thumper too, right?
    #1
  2. Mr. C

    Mr. C I need more bike time!!

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    Cool way to spend some time with your son. That time together will be invaluable.

    Can't wait to see that bike all done up with ape hangers (and your subsequent 'round the world trip report on it)!!! :clap
    #2
  3. brentde3

    brentde3 Should be outside

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    We've decided that we're going to replace the plastics, so away with those:
    [​IMG]

    And we suddenly realized just how dirty this bike is. I doubt it's had a bath for years. The plug was all but destroyed (hence the paper towel plugging up the plug hole). The fork seals are shot. The exhaust pipe (especially the header) is just about rusted away. And, though I couldn't really get a picture of it, the oil bottle and the triples were just caked with awful black goo. Here's a pic of the carb to illustrate the black goo:

    [​IMG]

    The first order of business, then, was to clean the damn thing so I could actually see what I was doing. I'll probably regret it later, but I gave it a liberal coating of degreaser, loaded it up in the trunk of the Ford Focus (ah, the shit I've done to that poor car over the years) and took it down to the local car wash for a bit of high pressure fun. Here's what the carb looks like after:

    [​IMG]

    Holy crap! There's some silver in there! And the rest of the bike looks better too:

    [​IMG]

    But the exhaust still looks terrible. Probably just need to replace that (if I can get the bolts free).

    [​IMG]

    That was enough work for today. It's hard to justify garage time with a newborn in the house. Can't tell you how much fun this is. Got me thinking about my first bike (also a Yamaha, a YS50. That was one hell of a sweet bike. I wish I had it back. Street-legal 50cc full-fairing sport bike). Also got me thinking that this "restoration" is just about the most stress-free thing I've worked on. We can always rig some sort of solution on this thing. No inspection stickers to worry about.

    It'll be a wicked first bike when we're finished.
    #3
  4. LILBIT

    LILBIT Ride you must.

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    The training wheel bicycle rule did wonders for my boy. He was really lazy about learning to ride without them until a PW came home. Learned in a hurry then.
    #4
  5. High-Side

    High-Side Highly Adventurous

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    Cool - below is my seven year old son on his Honda CRF50F. He loves to rip around on it at the ranch. :D


    [​IMG]

    [​IMG]
    #5
  6. dirthauler

    dirthauler rolling rototiller

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    sweet guy!! i got my step daughter started on a pw!! it's now gone through four kids and still hasn't had any real work done to it
    here's a pic of my kiddo on her ttr 125l
    [​IMG]

    [​IMG]
    #6
  7. rufus

    rufus We're burning daylight...

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    The best mod you can do to the pw50 is the clutch mod. In stock condition, by the time the clutch quits slipping and gets hooked up completely it is going way too fast for most beginners. The clutch is just a set of brake shoes inside a drum. The mod is to cut off about half the shoe lengthwise. I did mine on the grinder. It puts the same pressure on a smaller area and makes the clutch hook up at a lower rpm. Softer springs will make the clutch hook up even a little better. This makes it lots easier for a kid to ride. Don't worry about the clutch wearing out. I know guys who raced a pw for years with the same set of cut down shoes/pads. Once you take it apart you will see how simple it is.
    You can also get the gears from a yamaha moped (qt50 IIRC). This gears it lower and makes it easier to ride slow.BUT, it will accelerate faster. You will need a different length driveshaft. I don't remember if it was longer or shorter. I bought one ready to go. But lots of people made a new drives shaft from a socket extension. 1/2 inch drive I think. It is all simple to do. I bet there you can find all of this info somewhere on the internet.
    #7
  8. Reposado1800

    Reposado1800 Juicy J fan!

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    I had one of those for my kids to learn on. I sold it 1st day in the paper.
    Remember they are pretty damn fast with a 30lb kid on them!!! The older ones like the red one don't have governors so be careful. One handful of throttle and you will be running behind a kid screaming as he goes toward t-boning a parked vehicle. DAMHIK!!
    These are great bikes and worth passing on down to friends and family.
    I upgraded to a pair of SSR110B pit bikes and first thing had to restrict the throttle.
    #8
  9. dbarale

    dbarale Squiddly slow

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    Pretty cool bike the little guy looks like he will love it but, before you replace the fork seals, you may want to take a closer look at that right fork tube. From the pics it looks like it could be bent which would make seal replacement pointless...
    #9
    ruckusracing likes this.
  10. High-Side

    High-Side Highly Adventurous

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    The Honda CRF50F's have a set screw on the throttle that you can adjust to control the speed. I had it adjusted to a walking pace on my son's first day, but had it opened all the up by lunch. I didn't tell him it had three gears until it wasn't fast enough in first. :D
    #10
  11. Reposado1800

    Reposado1800 Juicy J fan!

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    I had the great pleasure of teaching my kids to ride in the infield of a horse track in Del Rio, TX. It was probably one of the best moments in my life just riding along side them for the 1st time.:1drink
    The real name for the red ones is Yamaha YZinger.
    #11
  12. Cervelorod

    Cervelorod n00b

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    IIRC the forks do not have seals in the real sense. They are just springs with grease on them to "damp" the action.

    Also whilst you have it apart check under the head tube for cracking. If your center stand seems like it doesn't work correctly, that is a sure sign the headtube is cracked. I welded mine with oxy/act but any method would work.

    Excellent advice on the clutch mod

    rod
    #12
  13. brentde3

    brentde3 Should be outside

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    Thanks guys for all the insight, especially the info regarding the gearbox and forks. I told myself I wasn't going to buy a Clymer's for this bike, but I think I'll go ahead and take the plunge. I've got two degrees in English and I teach literature. That makes me the shade-tree mechanic that needs a book :1drink.

    The fork looks bent in the picture, but not so much in real-life. The action seems fine. The center-stand also works beautifully, but, again, thanks for the tips.

    All these pictures of kids on bikes are wonderful! Makes me think there's hope for the future :freaky.
    #13
  14. scarysharkface

    scarysharkface Truffle

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    Cool! Great dad! Frame-up restore on what may well be the most valuable thing you'll ever purchase! :clap
    #14
  15. brentde3

    brentde3 Should be outside

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    Well, a beautiful Sunday and an hour out in the garage. What with the five-year-old steering things and all, this will be a bit of a schizophrenic tear down. But, nothing like starting at the front and working one's way back...

    [​IMG]

    Yes, that's a little hand reaching for the PB Blaster. Here's a good chance to plug that stuff. It works! Get some! We used a good bit of it in order to get the exhaust off.

    [​IMG]

    I realize now, looking at these pictures, just how dirty my garage is. :puke1 The exhaust is extremely rusted. In fact, there are little pits and holes throughout the header.

    [​IMG]

    We might spend some time on fleabay and see what we can't come up with for a replacement. After that we got the airbox off and started looking at the carb. Everything on this bike is tiny!

    That was enough for this Sunday. One of these days, when school gets out, we'll speed up the process.
    #15
  16. motoxer667

    motoxer667 Been here awhile

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    By the colors on this PW it looks like it is a '86 or '87. Look on the throttle (front side) for a threaded hole for a throttle limiter.

    90149-05161-00 for the screw (special shape)
    95316-05700-00 for the nut

    Yamaha has all its parts cartalogs on-line. :clap

    My youngest son started on one. They are great. You should be able to make some money on it when you are ready to sell it. My son rode it for two years and it cost me $50 bucks (bought for $600 and sold for $550).
    #16
  17. Oly

    Oly Deadlines whooshing by

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    :clap Great pic.

    The look on his face says volumes and makes this all worth it. :thumb


    I get the same grin to this day. :ricky
    #17
  18. wavygravy87

    wavygravy87 Been here awhile

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    Abalabama
    Dude I rode one just like from bout age 6 till I was 18!! :super That is the toughest bike I have ever came across. My little cousin is still givin it hell and Im 22 now. You will have it forever.:D
    #18
  19. tdreyer

    tdreyer KTiM

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    Used to live in Crestview FL, now ????
    Subscribd!! If I get time tomorrow I'll post tomorrow some of the things I did to my boys PW. Without the throttle restrictor it'll do 30+ with me on it.
    #19
  20. Wings

    Wings marmaduked

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    Colorado Springs, CO
    Very cool-fantastic pic!!

    [​IMG]
    #20