1978 750 XS Special

Discussion in 'Old's Cool' started by Krantz, Oct 19, 2013.

  1. Krantz

    Krantz OMG aka WTF

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    Had a little time to work today-removed carbs,airbox,tried to pull out battery box- not without taking rear wheel off.
    One of the carbs has traces of water damage inside by the butterfly.


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    Then i found that the middle slider moves ok, the ones on each side are stuck.

    [​IMG]

    And a little mistery inside the airbox- what happened that melted it like that?

    [​IMG]
    #21
  2. Krantz

    Krantz OMG aka WTF

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    Interesting. PO told me that at some point the engine has been rebuilt.It certainly looks very clean.I took valve cover off- pristine!

    [​IMG]

    Can't see any wear on cam lobes. So if this is so good- do you think i should take the head off to see why it was seized? Or try to fire it up like that?

    [​IMG]
    #22
  3. concours

    concours WFO for 41 years

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    " So if this is so good- do you think i should take the head off to see why it was seized? Or try to fire it up like that?"

    I already chimed in... :deal not just some armchair mechanic, decades of professional mechanic experience counseling you. :freaky
    If you don't listen to me :buellerthen later you will :2cry :eek1

    Keep up the photos, story please!
    #23
  4. manxkipper

    manxkipper Fishpistel

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    I would strip and do the necessary inspections prior to running the bike. You do not know what is rusted or corroded internally. Gas contamination removes the oil film. BTW that cam is very dry.

    Given the corrosion on the motor on the outside it would be wise to do a proper investigation prior to any startups. If there is rust or corrosion in the motor your eventual bill will be Large if you try a startup now. Find out why the motor is seized first!
    #24
  5. NJ-Brett

    NJ-Brett Brett

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    I guess it depends.
    If you really like a bike, for whatever reason, it is worth it to fix it up.
    If you are looking to get off easy money wise, old bikes in bad shape are not a good bet.

    You can also fix something up just good enough to ride, and not make it look good, which saves a boat load of cash, but many can not resist spending money to make a bike look better.
    You find that brand new front fender on ebay for $75.00, or whatever and before you know it the bike looks like new, you spent as much as a new bike costs, and its value is 1/4 of what you have into it.

    That works if you like old bikes, they do not make them any more, now you get plastic covers liquid cooled things with bad seats.

    I got an old bike cheap, and am not worried about looks as its a dual sport.
    They do not make anything like it now, a 220 pound bike with good suspension in an air cooled 4 stroke full size bike version.

    I have about $1000.00 into it over time so far, and its been great fun to play with in the garage.

    I will likely not make money on the bike, but I have a 220 pound full size bike with good suspension to ride in the dirt...which is what I want.
    #25
  6. Krantz

    Krantz OMG aka WTF

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    Concours- if by listening to you means run away fast- while i appreciate it- already a little too late.Today went to lic. bureau and made a transfer- this baby is officially mine.So we have to get along somehow.But thank you all the same-any info is valuable.Mechanics are pretty straightforward on it,but still i'm careful to apply any force- anything broken is hard to replace. So far the only thing that bothers me is the oil filter- i cannot remove it.The bolt is seized solid. Maybe i will grind it off just to take the cover off, to see what is inside.
    #26
  7. NJ-Brett

    NJ-Brett Brett

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    Yes, any water that gets in the carbs will run into the motor, but will not get to the cams.
    Besides, new gaskets and seals on the top end would be a real good idea.
    #27
  8. concours

    concours WFO for 41 years

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    NP, don't mean to offend, just trying to get the point across. Do as you see fit, I'll be here watching the progress. ALL those oil filter bolts locked up, people evertightened them. I always took a large nut and TIG welded it on the head of it in situ.. A proper six point socket could also work if it's not too bitched up to start with.
    #28
  9. Krantz

    Krantz OMG aka WTF

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    No offense at all! I'm flattered you read it(holy crap, someone is interested!) For a moment i was going to stop-no one posted reply.Get your beer,popcorn, whatever you like!
    Here is where it gets nasty:
    [​IMG]

    What is the best way to clean the carb? All i have at the moment is break parts cleaner. It is good for many things,but not this.And those floats- do you think they are salvageable?
    #29
  10. Krantz

    Krantz OMG aka WTF

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    NJ _Brett
    That's just it- i like old(er) bikes.Modern stuff is fine, but somehow is... well, you probably know.That is why a lot of inmates have more than one.After fiddling with my slash 6 for a while i got a question from my much better half- what modern bike would you like to have(meaning not wrenching but ride)? My first thought "Am i lucky or what?" My second thought was - hm-m-m! What bike indeed? To answer that required a trip to our local Yamaha-Aprilla-Kawa- everything dealer.Just to look and compare.You know,what I'm talking about. So you can enjoyably burn coupla hrs walking around.Forget about time.Daydream a little.
    So the first thing you see-plastic.Lots of it.
    Then you realize- all these bikes are huge-ass machines!Like ford f350 on 2 wheels.Or cute little scooters.Then you go to the second floor. Aha! Moto Guzzi! They have racer.
    Too flashy.Nice,but too much bling to my taste.and G-7 classic.Nice, but something is missing.It's white,and simple- i would rather see it in red.And it requires some modification,don't even know what.If i would like to get something modern,it would be Kawasaki W650.Or you guessed it- TU250.
    I started riding in 7th grade.My first bike was pile of parts that i brought home one summer day. My mom almost had a heart attack.Nobody believed it would ride again. Took me 1 month,i was on the road. So to me,when i look at the bike and seat on it,i smell gas,my hands are dirty,tools clanking under the seat-that gets me excited.Yep! I'm officially old!
    So to return to the idea of this yamaha- no plans to make it showpiece.I just want to bring it to nice,tidy condition and ride it.After all, when you stop at the light,how many of these you see next to you?Chances are it's some HD or crotch rocket(nothing against either one)
    #30
  11. concours

    concours WFO for 41 years

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    The floats.. probably not... mine weren't. BUT clean them up GENTLY, shake, listen for sloshing, and then test by dropping in a bowl of WARM water.. watch for air bubbles... A single TINY hole can be soldered shut, mine were corroded through in several places
    [​IMG]


    [​IMG]
    #31
  12. brucifer

    brucifer Long timer

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    Pine Sol does wonders on that carb varnish. I was skeptical at first but it actually works. Some people water it down but I use it full strength--just keep an eye on it.
    Pour some in the float bowl for starters and let it sit for a while.
    #32
  13. zap2504

    zap2504 Dave E.

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    +1 on the Pine Sol (see the huge thread in Garage IIRC).
    Here's one in the Philly area (a Standard, not a Special but you get the picture): http://www.chinonthetank.com/2013/06/colins-xs750/. They're still fairly common, considering they didn't sell that well when new (at least compared to the competition).
    #33
  14. Krantz

    Krantz OMG aka WTF

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    Yesterday took carburators home.Purchased a bottle of pine sol of weired lavender scent(only one on the shelf) at our Wally.Anyway, after taking them apart as much as i could,and dipping them ,i've been varned of a possible eviction notice from my much better half.But the devil's syrop works- i'm getting movement in floats.
    However-now is the time to gloat and pronounce-I told you so-this is what i fished out of dropped oil pan. Looks like a piece of gear tooth and something unidentifiable.So the engine is coming out of the frame for a possible case splitting.Depending on the gear it is from,i'm hoping i do not have to do it.But i'm rarely that lucky.

    [​IMG]
    #34
  15. Krantz

    Krantz OMG aka WTF

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    And the gearbox

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    And the oil pan

    [​IMG]
    #35
  16. Krantz

    Krantz OMG aka WTF

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    Just to illustrate the point-that's how it looks when tidy.


    [​IMG]
    #36
  17. concours

    concours WFO for 41 years

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    The mystery unravels... maybe a kicker gear tooth?
    #37
  18. NJ-Brett

    NJ-Brett Brett

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    My xt200 had a broken kick start tooth...

    Remove any plastic/rubber parts and soak those carbs in pine sol over night.
    It works wonders.

    Really nice looking bikes they were, that black one is very sharp!

    I like the V7 classic as well, but I think they are cramped for a 6 foot person...

    #38
  19. concours

    concours WFO for 41 years

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    :hmmmmm:dunno:lurk
    #39
  20. CaptainCrunch

    CaptainCrunch Been here awhile

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    I can chime in - the Glorious Church of the Odoriferous Yet Highly Effective PineSol claims that in the holy text only the Original Scent is worthy of the true believers. All others are false idols sent to tempt you with more pleasing aromas and less burnt nose hair.
    #40