Anyone else having problems with the thatsdax GT 50 R motor???

Discussion in 'Motorized Bicycle General Discussion' started by donutguy, Aug 8, 2011.

  1. donutguy

    donutguy New Member

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    This thread is NOT to bash the guys at thatsdax, but is anyone else having issues with the GT50 R motors? I realize that they advertise on this message board and to be honest.....every dealing I have had with them has been pleasant and professional

    I've had 2 of these motors and both of them have had issues with head sealing and loss of compression.

    Right now Duane has one of my motors because he repaired it, but I can't get it to start.....so I sent it back.

    The second motor? The second motor lasted less then 20 miles before completely losing all compression.

    To say I am dismayed would be somewhat of a understatement. I have a call and an email into them, but my plan is to send the second motor back and ask for a refund for both motors.

    I'm sure that won't be a problem.....if for some reason it would be...I don't even want to go there right now.

    Like I said at the beginning of this thread- I'm not bashing the guys at thatsdax, things happen and I'm not upset-just extremely disappointed.

    I'm just curious if anyone else is having issues or am I the only guy. I'm not a kid who beats on his equipment, I've been running both motors at 30/1 oil gas and I take care of my stuff.
     
  2. kallsop

    kallsop New Member

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    I have one GT50R. Similar issues with one head bolt stripping, now repaired, and head bolts loosening after every ride. The low torque on the head bolts, about 7.5 lb.ft., does make me wonder how this high hp engine can reliably stay together. The block and threads are typically cheesy pot metal and there needs to be be deeper holes with more thread engagement with the head bolts so they can be torqued up more. IMO. Possibly the original engine design used tougher steel and the threads then were adequate? If I had one of these engines out of warranty, I'd be looking to install helicoils and larger diameter head bolts. With reliable head bolts, this will be a great engine.

    Keep us posted.
     
  3. donutguy

    donutguy New Member

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    Just got off the phone with Duane......super, super nice guy. He's going to refund me my money and let me keep the experimental motor he sent me. I just wanted to put something out there in case someone else was having issues.

    He did ask me about my jetting.......I just ran with whatever the carb came set up with.....my understanding is that it is set up with the middle jet out of 3 choices.

    If you have one of these motors....maybe that is something to look at.

    At any rate- I won't hesitate to continue to buy products from him-he runs a good and honest business......that means more to me then price.
     
  4. Mike B

    Mike B New Member

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    Nah, the problem is not DAX, the problem is Chinese 2 stroke engines.

    But I hear the 4 strokes are good.
     
  5. donutguy

    donutguy New Member

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    Absolutely Mike.....Duane has my business for as long as I am buying bike parts.

    He sent me a new improved motor (at no charge to me) for me to try. I will post up pics of the old version and the new version so everyone can see the major differences.

    The head is now a one piece unit....pretty much impossible to have head sealing problems as there is no separate head now.
     
  6. mapbike

    mapbike Active Member

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    Does the NEW version look anything like the stock version Head/Jug combo?


    Sounds like there was a good reason for these engines being designed this way originaly.

    Peace, map


     

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  7. donutguy

    donutguy New Member

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    Yup.....that's pretty close to what the new head looks like.
     
  8. gera229

    gera229 New Member

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    @donutguy
    "issues with head sealing and loss of compression"
    By head sealing you mean bolt stripping? Bolt loosening? (Is bolt stripping and bolt loosening the same thing?) Which or the problems did you have?

    Thats the original design of the motor and not improved.
    The stage 2 motor is an upgrade from this one and has more power and low end torque. A few high quality cheap things done will fix your problems, since you still have the motor, you can get longer head bolts(with red locktite), quality spark plug, and copper head gaskets (Get 2 of them to put on head to reduce compression).

    I plan to get the stage 2 one and see how it is. Ive owned one of these 1 piece motors in 47cc, no problems other than clutch springs blowing. I sold that Go kart that I had this engine on and plan on trying again with a heavy duty clutch and clutch pads since not many people seem to have problems with those springs.
     
    #8 gera229, Sep 18, 2011
    Last edited: Sep 18, 2011
  9. GEJoe

    GEJoe New Member

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