1980 yamaha 175cc oil pump not working...

Discussion in '2 smokers' started by clicheche, May 10, 2013.

  1. clicheche

    clicheche Adventurer

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    i've confirmed its not working, initially the light tells you as much, and now i can see that the oil does not come out of the pump and into the front of the carb...

    what goes wrong with these things?

    this 'rod', for lack of better term, moves in and out on the front of the pump. there anything to adjust, or should i just be getting a new one?

    thanks!
    #1
  2. anonny

    anonny What could go wrong?

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    I cant help but would suggest taking it apart and study it, they must be pretty simple. If you don't have a manual look for an online parts fiche.
    #2
  3. Scootern29

    Scootern29 Been here awhile

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    Those pumps are almost bullet proof. There is a guy on Yamaha Enduro.com that rebuilds them, his name is DEET.

    Worst case is block the hoses off and premix at 32:1 and you should be good.
    #3
  4. WRW9751

    WRW9751 7th Day Adventurist

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    They are bullet proof! It is NOT a pump, just a metering device! Find a manual and read. It is totally gravity fed. The only thing you really need to do is bleed it. Simply unscrew the Phillips head manually turn the white disk until no air bubbles. Replace screw. After that unscrew hose from intake do rotate the white disk again until oil appears and button it up. Worked a a Yamaha shop for a long time, never had one fail without someone dick'n with it.
    #4
  5. clicheche

    clicheche Adventurer

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    ya, it definitely appears mostly gravity fed.

    when you mention detach the intake, you mean the hose connecting to the carburetor? there is oil going into the pump assembly, just not coming back out of it. will bleed it and such and see how it goes.

    thanks so far!
    #5
  6. YZEtc

    YZEtc Feel lucky?

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    You not only want to remove the little bleed screw on the pump body and drain out any air bubbles in the oil delivery (tank to pump) line, but you also want to get the pump opened up to what Yamaha Service Manuals call "maximum stroke".

    If I remember, there is a clip holding the oil pump control cable down against the crankcase.
    Remove the clip.
    Start the engine and let it idle or be at slightly above idle speed.
    Pull the oil pump control cable up out of it's resting spot while the engine runs - doing this rotates the pulley on the oil pump that controls how long of a pump stroke the oil pump makes with each stroke, moving it to max stroke.
    If you do this with the supply line from pump to carburetor removed, watch for little spurts of oil without any air bubbles.
    When I've used this technique, less than a minute of running did the trick.

    This will greatly increase the amount of oil pumped toward the carburetor in a much smaller amount of time compared to normal operation of the engine, and is the last step in fully bleeding the Autolube oiling system.

    As for the oil indicator light on a DT-175G, it lights up on two occasions:

    1) While in neutral.
    2) When the oil in the tank falls to a certain level.
    #6
  7. buls4evr

    buls4evr No Marks....

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    This is really bad advice in more ways than 1 OP. Keep that pump and fix it. Try the driving gear system that runs off the crank. They usually have a small nylon like gear set that might need replacing. Like others have said they are ultra reliable and give you the opportunity to run straight pump gas. Also make sure there are no obstructions in the lines... dead spider?
    #7
  8. clicheche

    clicheche Adventurer

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    dead spider what?!

    so from having ZERO oil coming out of the pump to the carb, i now have spurts, albeit small, and for a reason... no air involved after bleeding. saw the clip, will look at it again. not sure HOW the system actually functions, i wish i did.

    the oil light was on while riding it. it then went off. (oil reservoir quite full)
    who knows. thank you for all the advice so far.

    i figure more oil can't hurt. is it normal to hear a pronounced clanking/ticking/ metal clapping with this bike/2 strokes/old 2 strokes? it feels as though it rides much more comfortably. i threw in like the smallest imaginable amount of oil in the tank (1/8 full) just to be safe while i troubleshoot.

    i would really rather use the pump than resorting to the premix hooplah, but worst case scenario you can run the bike with this method.

    i noticed that when i pushed on the large black plastic washer, the spurt of oil exiting the pump was much larger, this i liked, as i'm not sure how much that crankcase has seen 2 stroke oil in the short term past.

    @ idle, how much oil are we talking, being put forth to the carb?

    how dangerous is it to ride the bike with zero oil? YIKES.
    (only ever gone 15km while testing it)

    (will keep posts shorter):D
    #8
  9. clicheche

    clicheche Adventurer

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    is the oil pump control cable clip white by chance? it holds the cable and restricts some other rotational thing. stops it at a certain point.
    #9
  10. YZEtc

    YZEtc Feel lucky?

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    #10
  11. clicheche

    clicheche Adventurer

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    that clip, i believe has one sole purpose, and that is to keep the cable from being pulled out of the oil pump housing.

    not sure how it would allow for more pumping of oil.

    damn. i've read through the manual, and not much else is mentioned. i guess we'll see how it runs. not sure what to do. concerned that i had to essentially pump it by hand by pushing the black plastic against the spring over and over to get spurts of oil through the hose. never any air bubbles though.

    maybe i'm just not reading the instructions on the second/thorough bleed method.
    #11
  12. clicheche

    clicheche Adventurer

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    wait. i think it makes sense. i'll give it a try. i wonder if i managed to do that manually with my hand turning the pulley as far as i could. thanks again!
    #12
  13. clicheche

    clicheche Adventurer

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    so going forward, long term, i don't see how the clip removal alters the amount of oil flow... as the position of the throttle cable doesn't really change. after having manually pulled on it, it rotated further... is that all it takes?
    #13
  14. YZEtc

    YZEtc Feel lucky?

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    You remove the clip, grab ahold of the oil pump cable, and pull it out of the hole where it sits in the crankcase.
    This rotates the pulley on the oil pump.
    This is done while the engine idles.
    #14
  15. clicheche

    clicheche Adventurer

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    thanks!

    so i did that. and that's that? it'll just work continuing forward?

    awesome.
    #15
  16. YZEtc

    YZEtc Feel lucky?

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    That's that.
    #16
  17. clicheche

    clicheche Adventurer

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    ya i think so. will update once i take it to my dad's.

    going to replace those notorious brake shoes.
    #17
  18. clicheche

    clicheche Adventurer

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    when's a good time for a rebuild? how many miles-ish?

    like 15? it has 3 on it right now
    #18
  19. clicheche

    clicheche Adventurer

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    new brakes, feels safe and tight. love it.

    oil pump is definitely working. crazy blue smoke flying out the back whilst climbing a huge inner city hill. what a blast. i love this bike. anyone have an idea where the bike likes to run as far as rpms?

    i was thinking roughly 4500-7000 was it's best pull.

    radical bike. so fun.
    #19
  20. Chillis

    Chillis Long timer

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    It's a two stroke. Get it on the pipe and go. Just don't run max rpm for extended periods.
    #20