Yamaha PW80 YZinger

Discussion in 'Pit Bikes & Mini's' started by stpolo, Sep 14, 2005.



  1. stpolo

    stpolo Rookie DRN Member

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    I have a 1990+ (don't remember exact year) Yamaha PW80 Yzinger bike. It was a starter bike when I was a kid. I'm 25 now and have a 7 month old son. (I know a little to young yet!) The problem that I'm having is the bike has been sitting for about 5 years without being run. There has been winterizer in the gas. I'm going to drain the oil and the gas. But I thought that I would just give her a kick to see if it starts. And it did! The only problem that I have is that gas seems to continue to run out of the over flow hose at the bottom of the engine. Even when I shut the bike off. It does stop after a while. I'm just wondering where to start? Any ideas are greatly appreciated. Thank for reading.........

  2. stpolo

    stpolo Rookie DRN Member

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    Wow this site is great. I'm such a noob to dirtbikes, but I love to mod my car. So I think that this should come easy? Sorry for creating this thread without searching. But these are some of the things that I found. Please tell me if I'm going in the correct direction? I also have to change the back tire? Also the muffler fell off when I was a kid and we never replaced it. Will that effect performance? It didn't seem too. Any helpful advise would be greatly appreciated. Found some mods to do on it too!

    "A possibility may be that the rubber needle tip on the needle and seat assembly is old, hard, and will not seat properly. I'd clean up the seat with carb cleaner and a Q tip, replace the needle, reset the float level (the float isn't somehow logged with gas and sinking is it?) and clean the carb real good with carb cleaner. If your bike is like the PW80 then it's jetted too rich from the factory. I had no top end RPMs at all until I went down 1 size on the main, raised the needle clip 1 position and opened up the air box a little. It was a whole new bike after that. It's still too rich on the main jet, but I haven't found a leaner size to try yet."

    "I have a PW50 that was having the same problem with the gas spitting out the overflow while kicking it, it would also bog down when the choke was not on when you let off the throttle. I put a new float needle in it and seemed to fix the problem. Hope this helps."

    "The float may be stuck. Give the base of the carby a solid tap with a hammer or pick up the back end of the bike and drop it to try and free it up. If that fails, pulling the bottom of the carby off and reinstalling usuall works for me."

    "I have done a few things to my nephew's PW80 to help the performance. Most are inexpensive and you can do them yourself.

    1) Remove the rubber snorkel on the airbox, this allows it to rev much better.

    2) Raise the clip on the needle in the carburetor on notch.

    3) Remove the exhaust silencer and cut off the restrictive cone piece on the end of it.

    4) Redrill a new rear shock mounting hole 1" further back on the frame, this will raise the back of the bike up and improve handling.

    5) Raise the fork oil height to 6.5" from the top of the tube. Make sure the forks are compressed and springs are removed when doing this.

    6) Add a 1/2" preload spacer to the top of the fork spring. (PVC tubing works well).

    7) Remove some of the steel balls in the centrifugal clutch to raise the engagement rpm. (Leave an open space in between each one and distribute them evenly).

    8) Change the gearing (We are in the process of finding the right setup)."


    "I'll try opening up the air box, raising the clip 1 notch (to #2), installing a 14 tooth countershaft sprocket (from a 15), and dropping the main 2 sizes to a 115 (for a start). I think I'll keep the autolube for the time being, unless you think it makes a significant difference in how it runs to go with premix. Does any one make a sock type air filter that will fit the carb? Thank alot for the tips."
  3. Culprit

    Culprit Rookie DRN Member

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    Just clean the carb and replace the muffler. After sitting that long it does not matter what fuel stabilizer you use, that carb is full of dung.... that is why it is coming out the overflow tubes!
  4. stpolo

    stpolo Rookie DRN Member

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    Thanks Culprit!!! That will be the first thing that I do!!!

    Would it be a problem if I didn't put a muffler on? Just curious.
  5. GhostRider32

    GhostRider32 Rookie DRN Member

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    I have always heard that the bike is tuned to run with the muffler on when the engineers are designing it. If it was me, I'd put the muffler back on it.
  6. kneeboardpro9

    kneeboardpro9 Rookie DRN Member

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    Need help!!!

    About 1 year ago, i got my cousins old pw and fixed it up. I have tuned the carb, raised suspension, and recently bored out cylinder for a 48mm wiseco piston. I am running NGK Iridium spark plugs and Synthetic racin 2-stroke oil. After not even a week of having the cylinder bored, The bike just stopped running. It is afterfiring in the exhaust as soon as I start it and will not stop(even after beeing warmed up). I have been through 5 spark plugs in 1 hour and have no clue what is the problem. I have not messed with the carburator since it has started running. It was running fine with everything And I have not done amy changing since. Isince it quit running, i have tried running with silencer tip and even standard plugs. I dont know why it will not burn all of fuel. I think I have ruled out timing since the timing is preset in the flywheel and can not move. If anybody knows what can help, please let me know!

    Thanks,
    Ken Folsom
  7. shawn3189

    shawn3189 Rookie DRN Member

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    i heard the oil injectors jet clogged so you might want to check that
  8. kneeboardpro9

    kneeboardpro9 Rookie DRN Member

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    I only wish i had read this earlier! I have now been having trouble with my carb so i decided to do a complete overhaul on it. When I was on My way to the hardware store, I noticed the bike acting sluggish. I thought it was a plug foulin g so i turned and stoped at my fire station. I looked to see, by my surprise, the oiler hose had come disconeected. I ran it for a bout a mile before i noticed this. I scalded the rings and ruined a gasket. I am hoping to have all this done before thanksgiving. After that I am selling the bike. (any intersested on a 1996 pw80??) I am lloking to get a 2003 or newer Yamaha ttr 125 LE. (anyone have one they want to sell??) Thanks for all your help and i will post whatever info I do with mine.
  9. X-Rider

    X-Rider Rookie DRN Member

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    Hey stpolo... I'm pretty sure I know exactly why the gas keeps flowing out your tube...same thing happened to me. If you take it to a repair shop they'll probably tell you that you need a new float (part of the carburator), so at the same time just ask for a general tune-up, they're cheap. So, thats the solution to your problem. Hope I helped:)
  10. IndyMX

    IndyMX Subscriber

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    Wow, talk about dragging one out of the grave...

    That was a 2 year old post you just replied to, and the dude you replied to hasn't been on the site in over a year.

    I doubt he'll get your message.
  11. flyingfuzzball

    flyingfuzzball Rookie DRN Member

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    LOL

    ya never know he might go

    hey maybe i should go back on DRN and see this thread and go HEY i should get a new bike and resurrect my love of riding just like some one resurrected my dead thread

    :D
  12. stpolo

    stpolo Rookie DRN Member

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    Haha, I got it guys! Thank you so much. My son is two and a half so I have some time to tinker with it. I'm working on our go kart and dirt bike. Still haven't worked on either of them yet. But will. Thanks for the replies!!!!!!!!!
  13. 96 YZ 125

    96 YZ 125 Rookie DRN Member

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    ken, you might need to adjust the jetting if your fouling plugs. i had the same problem with my pw but once it was jetted properly it runs fine and havent fouled a plug since
  14. Spencer99

    Spencer99 Rookie DRN Member

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