Very Successful Lifan 125cc swap into 1981 Honda C70 Passport

Discussion in 'Battle Scooters' started by DRconvertible, Dec 16, 2015.

  1. DRconvertible

    DRconvertible Lurking in SoCal

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    Because the 90 based motors and 50 based motors use different bolt patterns on the bottom of the engine, you either need to use the DrATV adapter plate and widen your footpeg bar on the right side to fit the Lifan motor, or use a 50 based (50,70cc) bar widened to fit the Lifan motor, or...the Dr has a footpeg bar from a European C70 derivative that will bolt right onto the Lifan and is wide enough in stock form. It is available new at: http://dratv.com/thwoforliwil.html . The current price is $45.95. It is a genuine Honda part that is brand new and fit without modification to the bottom of my 125 Lifan and cleared my aftermarket exhaust. Not cheap, but a decent set on Ebay that will require work cost almost as much. It is wider than stock so the relationship between the rider's feet and the controls are a little different. Not a ton, but a little adjustment is necessary that you won't notice after a ride or two.
    #41
  2. DRconvertible

    DRconvertible Lurking in SoCal

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    They are very similar but vary in a number of dimensions. The C70/Passport frame uses the Honda 50 based bolt pattern that is used in the pitbike motors. The CT90/CT110 uses the Honda 90 bolt pattern (a little further spread between mounts and slightly different sprocket alignment) so the pitbike motors do not directly bolt in. The adapters available at DrATV are simple to work with and allow for a near bolt-in experience.

    Because they share so many common parts, one can built a "Frankenbike" very easily. I would like to build a CT90 style bike using a Passport frame and tank, swingarm and rear wheel, and a CT90 front end, dual sport tires and high pitbike exhaust. Some minor mods would be needed, but for the most part a bike like this would just kinda fall together.
    #42
  3. DRconvertible

    DRconvertible Lurking in SoCal

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    Good deal. Looking forward to your pics and to hear about your first ride.
    #43
  4. INTERNETRACECAR

    INTERNETRACECAR livin' la vida lifan

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    That's exactly what I was looking for, thanks! I picked up that very same pipe (and it sounds boss even with the 70) so I'll be damn near cloning your setup, and will report back on how it all goes.
    #44
  5. fullmetalscooter

    fullmetalscooter Let me take this duck off

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    It would be doable if you lived near a old motorcycle graveyard. I know that ct 90/ 110 frames / backets cases seem common on clist . passport don't seem as common. It would be a neat project .
    #45
  6. CA_Strom

    CA_Strom Cunning Linguist Supporter

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    After just doing the Lifan 125cc into a Honda CT200, I'd highly recommend that frame for a swap. Lots of old CT200 frames out there in basket case condition. All that the ct200 frame requires is 5 minutes with a grinder to clearance a couple of areas on the sheet metal frame to allow the entire to fit. Both mounting bolts line up perfectly after this grinding.
    #46
  7. DRconvertible

    DRconvertible Lurking in SoCal

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    Very true. Most Passports seem to have survived in a garage and are at least in reasonably good shape with low miles and sellers usually ask between $1K and $2K, even for non-runners. It's crazy to think that a fifty year old CT is in greater supply than a 30 year old, but it seems to be true.

    Agree. Easier starting point but the adapters make the job almost as easy for CT90/110 frames and those seem to be in even greater numbers.
    #47
  8. hugemoth

    hugemoth Big Brother is watching you!

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    No need for adapters on the CT frame if you have a welder, grinder, and drill.
    #48
  9. fullmetalscooter

    fullmetalscooter Let me take this duck off

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    Your right about the passports a 81 just pop up for 400 bucks were I live, which 300 bucks USA cash. Sat in a garage for 15 years. I would guess 2 days to make it run again if it's as good as it looks . Battery , oil , check everyone over and 5 kick starts latter if your lucky it runs. i don't have room for another scooter or I would consider it.
    #49
  10. CA_Strom

    CA_Strom Cunning Linguist Supporter

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    Well I got my 1965 ct200/Lifan 125 conversion all buttoned up and ready for a test ride.... I had to cut a small notch out of the left timing cover to get it to clear my OEM pegs; not a big deal since that area of the cover is purely cosmetic. You can't see the notch once the pegs are mounted.

    The new Lifan fires up on an easy 1/2 kick and purrs like a kitten.... Until I try to ride it and realize it's woefully under-jetted. The Chineeze 22mm "racing carb" that came with my kit has an 83 main and a 32 idle jet the best I can tell. It idled, but it would bog and stutter as soon as you tried to open the throttle past 1/4. I took the air cleaner off and that only made it worse. The needle came in the highest clip setting from the factory. Based on looking at the plug, it's running really really lean.

    Thanks to DRconvertibles informative post, I ordered up some Jets from Jets-r-Us yesterday and immediately got a shipping confirmation back. I should have an assortment of larger jets in a few days and hopefully that's my last issue. Thanks again for all the information in this thread. The Lifan conversion was an enjoyable project and I'd highly recommend it for anyone. Pictures will come once I get a chance....
    #50
  11. CA_Strom

    CA_Strom Cunning Linguist Supporter

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  12. DRconvertible

    DRconvertible Lurking in SoCal

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    Been a few months since I updated this thread but the 125 powered Passport is doing well. Power is good. Shifting is good. Lights are bright.

    As a Father's Day present, my daughter asked to take me for a ride this morning -- her on the Passport, me on my Royal Enfield.

    We covered about 60 miles of coastal Orange County roads, went to the top of the world, had breakfast at the Orange Inn and at one point went 62 mph indicated between Laguna and Newport.

    [​IMG]



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    #52
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  13. DRconvertible

    DRconvertible Lurking in SoCal

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    The Passport is for sale in the Flea Market. If you're in the market for a little hot rod vintage scooter, this might be your next bike.
    #53
  14. Vangruver

    Vangruver CubAllStar

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    Question regarding the bike's electrical.

    I know you used parts to pull down the voltage from 12 to 6, to charge the battery and the rest of the bike electrical; so i'm curious if you still have a point after the engine where you can utilize 12volts DC [for various electrical accessories]

    Or is the voltage coming from the stater too dirty to utilize to power 12v accessories.
    #54
  15. YamaGeek

    YamaGeek Skeletor sparklemuffin.

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    I adapted a magneto/CDI powered non Lifan clone 125 to a Honda C102, using the stock, 3 position key/ignition. You have to set up a small Radio Shack 12 volt DTSP relay to ground out the CDI terminal 'kill switch' terminal when the key power is off. When the key is on, the relay draws a tiny amount of 12 volt power to energize the relay open. Since my bike uses the replaceable bulbs, I've gone all 12 volt bulbs, brighter and better conductivity in a marine air environment.
    #55
  16. YamaGeek

    YamaGeek Skeletor sparklemuffin.

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    You could make a 12 volt regulator using Radio Shack TTR regulator, * if * you're good with electronics scratch building. You would have to completely isolate the 12 volt DC output circuit from the bike frame and ground circuit of the 6 volt regulator. You'd also be a bit power limited, about 1.2 amps max.
    #56
  17. YamaGeek

    YamaGeek Skeletor sparklemuffin.

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    [​IMG]
    #57
  18. Vangruver

    Vangruver CubAllStar

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    I am decent with electronics, but I would need to study the schematics and proof read the output details. I suppose I "could" do it.....

    I'm just after a means to put in a 12v motor to my 81 passport, and install some accessories that are for more modern motorcycles. I guess I have all winter to figure that out.
    #58
  19. CA_Strom

    CA_Strom Cunning Linguist Supporter

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    I did the Lifan 125 swap in my 1965 ct200 using a four wire switch from Dr ATV. It works perfectly with two wires to power the Cdi and electrics and two for the kill circuit. It was a direct bolt on and fits perfectly under the stock side cover. $19.95 and a bargain to solve the issue.
    #59
  20. DRconvertible

    DRconvertible Lurking in SoCal

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    To keep things simple, the answer is no. The voltage from the stator is AC and varies in voltage up to 45 volts or so depending upon RPM. It must be regulated in some way to keep from killing bulbs and rectified to keep from killing other 12v DC accessories. You will need to choose between a six or 12 volt lighting and charging system. The Lifan is designed to power a 12 volt system so converting to 12 volt is as easy as using a 12V reg/rec and replacing bulbs with 12 volt bulbs.

    Yes, as demonstrated above, there are other ways to do it, but the reg/rec units available for $20 or so do a good job and do it very simply.

    And CA_Strom is correct, the Passport style ignition switch will greatly simplify the key switch circuit when it comes to the wiring and while it can be modified using a separate relay to keep from killing the CDI, it's going to cost just as much and be more complicated in the end.
    #60
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