73 rt1 360 converted to Mx360 motor help

Discussion in '2 smokers' started by Clayclev, Dec 24, 2013.

  1. Clayclev

    Clayclev Adventurer

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    I've got a 73 Rt1 360 and striped it down to mx. I've been racing it and it's been really enjoyable. But when I go to the bigger tracks it seems like the bike is a turd.. Is the rt1 motor the same as the mx360? The rt1 dt1 and mx bikes all look alike and all have interchangable parts. I just ordered new work shocks and circle f pipe. Trying to figure out how to post some pics of the bike. I'm on the iphone app
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  2. concours

    concours WFO for 44 years

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    Hi Clay, welcome. More info, pics please. What has been done? Plug chops? pics of plug please. These RT's had a different feel, low -end grunt, but fell off on the top. Did you run through the crank seals? GYT pipe on hand?
    #2
  3. Clayclev

    Clayclev Adventurer

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    Im on the iphone app and it only has a URL link for photos. I'm use to clicking the pic icon and just open my library and downloading pic. I'll have to learn something new.. :(. I have put lighter front wheel. Work shocks mx tank. Newer kawi seat and basonni pipe on. I went threw the motor and put new crank and rod in. It does have good low end but doesn't have good rpm rev. And falls on its face.
    <a href="http://s975.photobucket.com/user/clayclev82/media/image_zpsf62cefb6.jpg.html" target="_blank"><img src="http://i975.photobucket.com/albums/ae237/clayclev82/image_zpsf62cefb6.jpg" border="0" alt=" photo image_zpsf62cefb6.jpg"/></a>
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  4. Clayclev

    Clayclev Adventurer

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    <a href="http://s975.photobucket.com/user/clayclev82/media/image_zps15171623.jpg.html" target="_blank"><img src="http://i975.photobucket.com/albums/ae237/clayclev82/image_zps15171623.jpg" border="0" alt=" photo image_zps15171623.jpg"/></a>




    And me racing against post vintage watercooled. I won this race.
    <a href="http://s975.photobucket.com/user/clayclev82/media/image_zps965651d5.jpg.html" target="_blank"><img src="http://i975.photobucket.com/albums/ae237/clayclev82/image_zps965651d5.jpg" border="0" alt=" photo image_zps965651d5.jpg"/></a>

    <a href="http://s975.photobucket.com/user/clayclev82/media/image_zpsb0936776.jpg.html" target="_blank"><img src="http://i975.photobucket.com/albums/ae237/clayclev82/image_zpsb0936776.jpg" border="0" alt=" photo image_zpsb0936776.jpg"/></a>
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  5. concours

    concours WFO for 44 years

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    "Im on the iphone app and it only has a URL link for photos. I'm use to clicking the pic icon and just open my library and downloading pic. I'll have to learn something new.. :(. I have put lighter front wheel. Work shocks mx tank. Newer kawi seat and basonni pipe on. I went threw the motor and put new crank and rod in. It does have good low end but doesn't have good rpm rev. And falls on its face.
    "

    That is, unfortunately, the nature of the beast. The Dt250 would rev and continue to make power way higher in the rev range. If you tune to exploit higher revs, you will lose some bottom/mid (hence power valves). What reeds are you running? That Bassani pipe may not be the best for top end. GYT Kit pipe was good, back in the day. Be careful, sneak up slowly on the power peak, that big piston WILL squeak, I can tell you from experience. The finning is marginal on that cyl. A thinner head gasket can help the squish band that's very wide from OEM.
    #5
  6. concours

    concours WFO for 44 years

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    we'll need a WOT plug chop... if we're too fat, we're giving up TONS of power
    #6
  7. Clayclev

    Clayclev Adventurer

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    I have a dt250 motor I have to redo might throw that in it. I ordered a circle f pipe. People swear by it plush I'm tires of the pipe burning my gear now.. Everything on rt1 motor is stock. I took the oil pump out.
    #7
  8. baloneyskin daddy

    baloneyskin daddy bikaholic

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    I believe the MX ran a single ring piston that was lighter and allowed freer revving and also had a close ratio gearbox.Try taking some weight off the flywheel.
    #8
  9. Clayclev

    Clayclev Adventurer

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    Will an mx360 gearbox fit in the rt1 case?! I'm sure it will cause most everything is interchangeable
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  10. stainlesscycle

    stainlesscycle Long timer

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    rt1 motor is nothing like the mx360 performance wise.... you could spend a fortune to make a rt1 perform like a stock mx360. but i'm assuming you have a rt3, not an rt1 (you said 1973- rt1 is earlier). rt3 is reed valve..

    either way, here are the big differences:
    mx360 has bigger carb, internal rotor flywheel, cylinder/porting, head, transmission, counterbalancer (removable), bigger reed cage, better airflow, etc etc. the mx360 makes gobs more hp.
    #10
  11. Clayclev

    Clayclev Adventurer

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    Thanks for the info. The case says rt1 and was told 73 when I bought bike. That doesn't bother me if it's a different year. I can swap out motors. Before I was gonna do that I wanted to know if the transmission for mx360 would fit in the rt1 case
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  12. Clayclev

    Clayclev Adventurer

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    Was wondering also, will I have to switch to a mx360 head when my circle f pipe comes in? No big deal if nobody knows I'll find out when I get pipe.
    #12
  13. stainlesscycle

    stainlesscycle Long timer

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    i would assume you will at least need to change the head, as the mx360 fins are shaved on right to allow pipe fit.. i'm not familiar with rt3 airbox setup, but mx360 airbox is pretty small to allow pipe crossover to the left. the rt3 pipe didn't crossover so i bet it's got a pretty good sized airbox..
    #13
  14. stainlesscycle

    stainlesscycle Long timer

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    there is a big difference between rt1 and rt3 - does your bike have reeds? - it looks like it does in the pics.

    i don't know if trans will swap. the mx360 cases are way different in the front half, for the counterbalancer setup. i don't know if back half is the same.
    #14
  15. Clayclev

    Clayclev Adventurer

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    I have removed the air box to save weight I have a k&n filter with sock on it now. Also the motor has reeds
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  16. Clayclev

    Clayclev Adventurer

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    I most be confused. The block has Rt1 stamped on it and has reeds so this makes it a 73 rt1 360 correct. What is a rt2 and rt3?
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  17. stainlesscycle

    stainlesscycle Long timer

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  18. Clayclev

    Clayclev Adventurer

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    Ok that's where the confusion is!! Bike is a 73 rt3. Dumb yamaha doesn't make since they mark it a rt1 when it's a rt3. I just bought a pair of 75 mx250 forks.
    #18
  19. stainlesscycle

    stainlesscycle Long timer

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    awesome upgrade. now you have suspension! throw a mx360 top end at it, and a bigger carb(i'm assuming you have a 32 or 34 on there.) /reeds to match that pipe/cylinder and it'll be a rocketship.
    #19
  20. Clayclev

    Clayclev Adventurer

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    What would be a good choice of reeds. Boysen? I've got the circle f pipe coming. I'm sure that will work.
    #20