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Thread: Big bore or big block?

  1. #1
    apriliaforum expert cokoop's Avatar
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    Big bore or big block?

    Got the wife a 2007 LX50. Only 350 miles and we got a good deal but geez it's slow. Tops out at 30mph and takes a week to get there. So I thought I'd work on it over the winter. I'm not looking for fast, just want to keep up with around town traffic. 40-45mph would be fine. Unfortunately the Vespa doesn't seem as tweakable as the SR50. She loves the scoot, doesn't want to get an MC endorsement and likes parking at the bike rack so trading it for a LX150 is off the table. So which way to go?

    Option 1, Big bore kit, cam and variator and rejet. I like this option because it keeps the original low mile engine. I think this should get what i want out of the scoot and is the more practical solution.

    Option 2, Find a wrecked LX150 and swap the engine. I understand the Leader engine will drop right in with a wiring harness and new shock. I know this will get it where I want, I like the big block sleeper concept (but the wife doesn't care) but I don't like not knowing the history of the donor motor.


    Anyone gone down this road or done the swap? Any thoughts on what kind of performance gains will result from option 1?
    2007 Tuono, 2007 SR50, Honda ST1100

  2. #2
    Honest always, feared often Micah / AF1 Racing's Avatar
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    The big block swap would be the best true solution to the slow problem. 70cc kits, well set up and tuned will slowly get you into the 40-45 mph range...but...the 150cc motor would make a night and day difference.
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  3. #3
    apriliaforum expert
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    Depends on local enforcement. Where I grew up they took note of unregisted bikes or bikes with Moped Stickers or Plates that were going over the max speed allowed for them and would really give you a hard time about it. A good friend got stopped on his 1978 Yamaha 49cc scooter and what caused him the most grief was that the speedometer was the same one you got on their 350cc bikes going to well over 100 mph. Got a number of warnings when I had my Mobyette back there and decided getting endorsed and 150cc+ was well worth it. Didn't have a bbk or any tunings done on the Mobyette so each time I got stopped everything checked out and it was more of a hassle than anything else.

    Back then the Mobyette didn't come with turn signals so I may have made myself a target when I put a windshield, turn signals and saddlebags on mine.

  4. #4
    apriliaforum expert cokoop's Avatar
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    Micah, have you ever heard about making a cut in the CDI to disable the rev limiter on one of these things?
    2007 Tuono, 2007 SR50, Honda ST1100

  5. #5
    Honest always, feared often Micah / AF1 Racing's Avatar
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    Yes, supposedly same cdi used on Scarabeo 50cc 4T. We do not sell the 50cc 4t motored bikes because locally they are dangerously slow so I am far from up to date on modding one.
    Diminished expectations is the key to happiness in life.

    Micah Shoemaker
    AF1 Racing
    9900 IH35N
    Austin, TX 78753
    micah@af1racing.com
    @ShoemakerMicah
    @AF1Racingaustin

  6. #6
    apriliaforum Member greg531's Avatar
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    Did you take out the carb restrictor and the washer in the variator? There is a thread on Modern Vespa on putting in the 70cc kit on 4T LX50's....
    http://http://modernvespa.com/forum/...ight=lx50+bore
    ScooterWest sells the kit and the cam..... http://http://www.scooterwest.com/it...o-valves)/3609
    2009 Aprilia Scarabeo 200
    2005 70cc Typhoon
    1963 Vespa GL
    http://www.grscooterclub.com/

  7. #7
    apriliaforum expert cokoop's Avatar
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    linke no worke

    no washer on the variator

    The majority of the vespa boards seem to think there are no restrictions on the North America 4T, which is a shame because any thing that slow without being held back should be furniture.
    2007 Tuono, 2007 SR50, Honda ST1100

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