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Project 1976 Yamaha YZ400

Discussion in '2 smokers' started by craydds, Feb 22, 2013.

  1. craydds

    craydds Long timer

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    So, should I just sand and repaint the old tank, or should I try to strip it and do some metal work? I have some ideas about how to pop out the dents, etc. But, it's just an old dirt bike, and I am going to RIDE it, that means I will crash it, too. If I make that tank too purdy, I'll be afraid to put a scratch on it. Need opinions from the faithful.
  2. anonny

    anonny What could go wrong?

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    Id be trying to get as much penetrating fluid in there as possible and put a rattle gun on it, if that doesn't work tighten the puller up then smack the head of the pusher bolt with a brass hammer.
  3. Scootern29

    Scootern29 Long timer

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    Depends on how good you want it. I am concerned with your "metal work". That tank should be aluminum. Get something plastic and keep the stock tank in the rafters. I have a desert tank if you want it.....cheap. It may be an old dirt bike but it is a one year bike........keep that in mind.
  4. craydds

    craydds Long timer

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    I am going to give it another try later on today. Will post results.
  5. craydds

    craydds Long timer

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    I may take you up on that desert tank. I found a source for tanks, they had everything except a 1976 YZ400 tank, I'll try to find the link. Got pics of your tank? Price? PM me if you like.
    edit: Found this at Clarke - http://clarkemfg.com/yz250125-7476-stock-capacity-p-244.html , says YZ250 but it might fit the 400 (?).
  6. craydds

    craydds Long timer

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    Do you doubt my abilities? :lol3
    Or, are you afraid of a massive explosion when I put a torch to it? :yikes
  7. Scootern29

    Scootern29 Long timer

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    Naw Ray, I was more concerned if it was a steel tank rather than aluminum. It should have an aluminum tank, that's all. It just didn't come out right in text after I reread it.
  8. craydds

    craydds Long timer

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    Yes, it is aluminum. Any tips on popping out some dents? One area around the gas cap is bashed in pretty badly, had bondo all over. I have an idea to put a little water in the tank, put the gas cap on - sealed well, close the petcock, and apply heat with a heat gun (no torch) to a dent, dent side down. Get it hot enough to boil the water and generate some steam pressure and pop out the dent. What could possibly go wrong? :(:
  9. Foot dragger

    Foot dragger singletracker

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    I have ground down cheap claw pullers to get them to fit in those slots,then had to take the puller apart and get things lined up then bolt the puller back together, and then heat the flywheel up,get good tension pulling on the hot flywheel then RAP it like you mean it on the end of the puller then smack the flywheel. Not pretty but I have most always gotten them off.
  10. ADK

    ADK *********************

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  11. Scootern29

    Scootern29 Long timer

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    Yes............but no.
  12. craydds

    craydds Long timer

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    Several good updates on the '76 YZ400 over the '75 MX. I sent Scootern29 a few links to some old articles on the '76 YZ - check 'em out, post #77 - posted them on Scooter's thread. I think it is going to be a FUN bike to RIDE !!!
  13. craydds

    craydds Long timer

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    Great tips! Thank you, dragger. I took the motor over to O'Reilly's and tried several pullers, found one that might work if I can take my angle grinder to the forks to get it to grab the slots, as you have done. I will go buy that puller tomorrow, take the grinder to it and give it a go.
  14. Foot dragger

    Foot dragger singletracker

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    Aluminum tanks will puff up or split a lot easier then one would think,I found out the hard way with a TT500 tank 1 day,its yard art now instead of a 300.00 tank. They are soft.
  15. craydds

    craydds Long timer

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    I tried my puller one more time today, tried all the tricks in the book... NO LUCK. Next step - cutting torch. :rofl
  16. craydds

    craydds Long timer

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    Do you think my crazy idea with the heat gun might work if I proceed cautiously?
    p.s. I have never worked aluminum, only car sheet metal.
  17. Foot dragger

    Foot dragger singletracker

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    If there's room around the outside of the flywheel its way better usually to grab and pull there,it doesnt look like there's room on the YZ400 between case and flywheel.
    I think if the puller gets ground too thin it would break,also when the flywheel comes loose from getting smacked it might become a hot flying object,Ive had em bounce off the wall behind me.
    Could be dangerous.
  18. Foot dragger

    Foot dragger singletracker

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    Im no bodywork guy. I know there was an old guy around here who used to make these odd shaped spoon things to fit inside gas tanks and then push/pull dents out with those.
    He had done it alot and Ive never tried it. Probably a bodywork guy would have some ideas.
  19. craydds

    craydds Long timer

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    That is the problem - NO room around the outside. Might be easier to grab the slots, can grind down the forks to fit, may have sufficient strength? Wish I had the tools to make my own puller, have several good ideas.
  20. craydds

    craydds Long timer

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    I heard once that some guys would fill the tank with water, put it in the freezer, and the expansion would pop out all the dents. Sounds kinda crazy, but... who knows?