Fun Wheel Drive - The DRMX 441

Discussion in 'Some Assembly Required' started by Friedom, Apr 11, 2017.

  1. Friedom

    Friedom Onward and upward!

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    Fair enough. So stock intake setup with an opened exhaust seems to be the way to go. I think I like the idea of sticking with the BST as well, as long as I can get it dialed in properly.



    - Fun Wheel Drive -
    #41
  2. Friedom

    Friedom Onward and upward!

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    Got the front end buttoned up today.
    Had a set of conversion bearings from all balls to mount the rmx stem and triples to the dr frame.
    Managed to press the wrong bearing onto the stem. Oops. Flip the stem over, press it the other way until the bearing is loose, put new bearing on, press stem and bearing back into place.
    I love having a press. Didn't get pictures of the process though, sorry.
    Also, was able to put a 10mm chunk of 5/16 drill bit (the base of the bit) into vice grips, drop them in between the cranks, and test if it would fit into the balancer pin hole. If it fits, then it's bad news and there's potential that your balancer pin can drift out of place and engine literally explode as the balancer and crank halves go out of sync.

    It did not fit.

    Sweet.

    [​IMG]

    - Fun Wheel Drive -
    #42
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  3. tatt2mike

    tatt2mike Been here awhile

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    Man that makes me nervous just seeing that little piece of drill bit hanging there. Glad it didn't fall in there. Good to hear it was drilled properly.
    #43
  4. tHEtREV

    tHEtREV Encouragement award recipient. tEAM iDIOT.

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    I looked at the pic before reading the description, so I thought he had dropped something in there, and then when I started reading, I was wondering how he dropped part of a drill bit in there.:lol3
    #44
  5. Friedom

    Friedom Onward and upward!

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    It's actually not a big deal if you drop it. It would just go down to the bottom of the case and you could pull it out from the clutch side with a magnet or grabbers.
    I learned this from fishing out broken gear teeth, shift drum bolt, washer and other stuff on my 1st DR.


    - Fun Wheel Drive -
    #45
  6. Friedom

    Friedom Onward and upward!

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    Got to test my own theory tonight. I was installing the second circlip for the wrist pin and sure enough it went down into the rabbit hole. Fished a magnet down and pulled it right back out. Crisis averted, but I did stuff some paper towel in there to prevent repeats.

    Coming along!

    [​IMG]

    - Fun Wheel Drive -
    #46
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  7. Friedom

    Friedom Onward and upward!

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    So do you think the bst33 will be up to the task of feeding the larger displacement?

    - Fun Wheel Drive -
    #47
  8. motolab

    motolab Long timer

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    I suppose the depends on how you define "up to the task". Can you clarify the question?

    Regards,

    Derek
    #48
  9. plugeye

    plugeye dreamer

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    why not? there are no head nor cam changes
    #49
  10. Friedom

    Friedom Onward and upward!

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    I've noticed that larger displacement engines tend to have larger bore carbs. There are probably other factors involved, but will my bst33 be sufficient?

    - Fun Wheel Drive -
    #50
  11. Friedom

    Friedom Onward and upward!

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    Thinking about a p&p while the head is at the shop.

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    #51
  12. plugeye

    plugeye dreamer

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    much easier, economical & non-regretful to leave it stock
    #52
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  13. Friedom

    Friedom Onward and upward!

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    Thanks. Excellent point. Think I'll eat instead.
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  14. motolab

    motolab Long timer

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    You could do the exhaust but not the intake if you want to improve detonation resistance.

    Regards,

    Derek
    #54
  15. motolab

    motolab Long timer

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    What constitutes sufficient?

    There's really not a carburetor that is too small for an application except that it may prevent the full power potential from being realized. On the other end of the spectrum a carburetor can be too large if it is capable of flowing more than the engine can use. Normally one would test this on the dynamometer by seeing if there is a sufficient difference in power between wide open and 75-80% opening. If not, then the carburetor is too big. Also, the bigger the carburetor, the more likely the engine is to fall on its face when opening the throttle rapidly (accelerator pump can help and CV can eliminate the problem). And keep in mind that the better the cylinder filling, the more critical ignition timing, compression, squish clearance, octane and exhaust flow (in no particular order) become in order to prevent detonation.

    Regards,

    Derek
    #55
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  16. Friedom

    Friedom Onward and upward!

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    Thanks Derek, I'd like to point out that this is an entirely separate bike and engine than the one that I had detonation issues on.

    - Fun Wheel Drive -
    #56
  17. motolab

    motolab Long timer

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    For what purpose?

    Regards,

    Derek
    #57
  18. Friedom

    Friedom Onward and upward!

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    Since you've pointed out detonation issues in my past on numerous occasions, I figured I'd point out that I only had said issues on 1 out of 8 dr350s that I've had.

    - Fun Wheel Drive -
    #58
  19. motolab

    motolab Long timer

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    To what end (i.e. what should my takeaway be?)?

    Regards,

    Derek
    #59
  20. CFH6604

    CFH6604 That's what she said.

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    Update(s)? Pics?
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