DT 400 engine identification

Discussion in '2 smokers' started by 2trally, Aug 14, 2012.

  1. 2trally

    2trally Adventurer

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    I'm probably buying a DT400 engine tomorrow from a salvage yard, and as the bikes have no bodywork (or much of anything else) and the tags on the steering stems are completely faded I want to be completely sure its a 400 and not a 360 or a 250. On google images they all appear quite different but I want something more concrete to go on.
    #1
  2. JeffS77

    JeffS77 cheap bastard

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    yamahaenduro.com has a vin# list to identify what it is..you have to register to use their site
    #2
  3. 2trally

    2trally Adventurer

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    I knew I should have written the vin's down. Oh well I can check tomorrow before I get it.

    By the way, is 150 to much for a seized engine?
    #3
  4. Shocktower

    Shocktower Long timer

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    I would pull the jug and see how bad it is that seams a little steep
    #4
  5. 2trally

    2trally Adventurer

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    Ya it seemed a little steep to me to but I got the engine anyways. They tried to turn it over by hand and couldn't, but neither the bottom end or the piston were actually seized. The seals between the tranny and the crankcase were leaking so a whole bunch of oil leaked into the case and gunked up around the crank. If they would have actually tried they could have gotten it to turn over. :D

    The cylinder needs a hone for sure but probably needs to be bored. Piston probably needs to be replaced. Transmission looks pristine, even the sprocket is barely worn. There isn't much rust. Crank bearings and connecting rod bearings seem good, no up and down play and they spin freely. None of the fasteners I've dealt with are stripped or seized, even the stupid screws holding the oil pump on. I think I will find some allen head or hex bolts to replace all the screws on this thing, using screws was a pretty poor way of cost cutting in my opinion.

    I really need to separate the cases and inspect everything to be sure but it seems to be in decent shape considering it came from a salvage yard. The one thing I'm not happy about is the stator was missing. Every DT400 I found there was missing its stator. After about 15 minutes of hunting I found a stator cover hanging off a random engine by one bolt... So at least I have all the covers.

    Oh, by the way its a 1975 DT400B. Are there any significant differences between engine models?
    #5
  6. 2trally

    2trally Adventurer

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    I guess I could have read on the cylinder were it says 397cc's
    #6
  7. Sniper X

    Sniper X De Oppresso Liber

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    yeah, 2 strokes from those times always had the displacement on the base of the cylinder, plus the Yamahas said the model in the first part of the VIN. Like DT400B000023411
    #7
  8. stainlesscycle

    stainlesscycle Long timer

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    not yamaha, that would be too easy. all 3 digit codes:

    http://home.comcast.net/~todwatts/Files/Model_codes.pdf

    i happily paid $200 for a complete but seized 1974 mx175 bottom end. a bit tougher to find than the dt400 though. you pay what ya gotta if you need it..
    #8