The Lifan engine thread

Discussion in 'Battle Scooters' started by hugemoth, Feb 22, 2011.

  1. pnw

    pnw Long timer

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    I got around to checking valve lash on my Lifan 1p52FMI with very low operating hours. I couldn't find manufacturer's recommendation. The original Honda CT90 motor had .002" (.05mm) listed for both intake and exhaust. Various unofficial recommendations for the Lifan seemed to be .003 to .005". The intake was at .002, exhaust had no measurable or palpable clearance. I set them at what ended up being .0025 intake and .003 exhaust. It had been taking two or three kicks cold to start along with choke, now it starts first kick every time with no choke (Mikuni VM22 clone carb).
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  2. WECSOG

    WECSOG Dirt Road Denizen

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    I just ordered another China clone engine; a Piranha 90 (actually 86cc). 49.5mm stroke.
    This is my second Piranha 90. I put one on my CT70 a few years ago and like it so much that I decided to get another one for my XL70. I might put the Jialing 125 that is currently in the XL70, in my CT90.
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  3. tylerjb

    tylerjb n00b

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    PNW, your bike looks great and well thought out. Couple questions on the overall refresh (I'm about to embark on a similar project with a 140cc engine):

    How do the those LED aux lights work for you, and does the stator keep up? Did you wire them off the battery or straight from the engine?

    Which rear shocks are those, and do you like them?

    What front/rear sprocket sizes did you go with?

    Did you update the front forks with heavier duty springs? If so, where from?

    Thanks for your thoughts!
  4. pnw

    pnw Long timer

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    PNW, your bike looks great and well thought out. Couple questions on the overall refresh (I'm about to embark on a similar project with a 140cc engine):

    Thanks, I think I have it where I want it. The lifan 125 (120) feels like it could run circles around the stock 90 and 110s that I have had, the 140 should be even better.


    How do the those LED aux lights work for you, and does the stator keep up? Did you wire them off the battery or straight from the engine?

    As a caveat: most of the things I put on this bike were left overs from prior bikes/projects so I just tried to make what I already had work even though it might not have been the best choice.
    The LEDs were for a Moto Guzzi that I sold when I found out I didn't have the skill or desire to ride a real motorcycle. They are 10W each, are really bright and I'm happy with them but they do tax the stator when all lights are lit. The stator on the 125 is a two pole unit with minimal output. Hugemoth felt that the 6 pole stators that fit on the 140s would fit the 125 also but the sellers on Amazon that I found for the 6 pole stators have stated that they don't fit on the 125s. They might be wrong but I don't want another unused part sitting on a shelf in the garage so I'm sticking with the stock stator. I replaced all of the lights including indicator lights with LEDs to minimize draw/maximize brightness and I run capacitors instead of a battery so the stator doesn't have to charge a battery and that probably saves something. At idle if I light the aux lights the LED headlight will cut out but the aux lights stay bright. Headlight has an operating voltage of 8-80v and the lighting circuit voltage drops from 14v to 6v when I turn on the aux lights (even though the aux lights are on the battery/charging circuit and the headlight is on the lighting circuit). Everything works with rpm just above idle (headlight turns back on by itself). I have some lower draw aux lights that work great also and might not cause the headlight to cut out (used them on a TW200 on a trip to Alaska), but they have a different mounting (on mirror stem base) that I didn't prefer for the CT. I still used the lighting circuit (yellow wire on the half wave stator) to power the headlight circuit, which also powers the tail running light but not the stop light. It is regulated by T connection with the regulator/rectifier but it is not rectified so I put a diode followed by a some capacitors in that circuit so it is also DC now and the capacitors smooth the current for the LEDs. I have read (but don't know for sure) that you can wire both the charging and lighting (white and yellow) stator wires into the regulator/rectifier and just run everything off of the charging circuit - the wiring harness wires are small gauge so I decided to use both circuits individually instead.

    With the 140 none of this should be an issue for you, if your motor doesn't come with the higher output 6 pole stator you should be able to upgrade your stator for not much money.


    Which rear shocks are those, and do you like them?

    For me the shocks were a must do, they seem just right to me for this bike,. I had them on a previous CT90 that I had returned to stock when I sold it. No more bottoming out the rear suspension and they provide a little needed lift. I got them from DrATV, on his website he stated 30% stiffer than stock, same looking shock on Ebay he stated 20% stiffer, i bought them from him on Ebay. DrATV is great but know that he sells a lot of his stuff on Ebay, often for a lower price and usually with free shipping. If you buy from his web site the shipping can be expensive.

    What front/rear sprocket sizes did you go with?

    I have the stock size 45 on the rear, I bought a few different fronts to try them out. So far I like 16t front for general use. If I do the WABDR this summer I'll bring the 13t with me, easy switch out and the 13t front makes it feel geared almost like the stock CT motor in the sub-transmission low setting.

    Did you update the front forks with heavier duty springs? If so, where from?

    I'm OK with the stock fork springs, I don't recall which multigrade motor oil I used but it all seems fine to me. Maybe if I installed stiffer springs I would like it more but I don't plan to do that.

    Good luck with your project, post pictures when you get into it.
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  5. Oscarjp

    Oscarjp n00b

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    Hey guys, first post, just finished last winter a 72 ct70 with a lifan 150cc 4up version. so far she is running great, 1 to 2 kicks to get her up running.

    Attached Files:

  6. WECSOG

    WECSOG Dirt Road Denizen

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    Nice! Do you have it plated?
    I have a '72 CT70 too, with a Piranha 90. Not plated, but I've been thinking about it.
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  7. Oscarjp

    Oscarjp n00b

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    yes all legal.
    thanks
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  8. WECSOG

    WECSOG Dirt Road Denizen

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    Welcome to advr btw.
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  9. Oscarjp

    Oscarjp n00b

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    thanks! let see your ct!
  10. WECSOG

    WECSOG Dirt Road Denizen

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    IMG_20160206_134926523.jpg
  11. Oscarjp

    Oscarjp n00b

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    nice, my frame look like that, maybe a little bit more rust when i bought it.

    20190515_180056.jpg
  12. WECSOG

    WECSOG Dirt Road Denizen

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    Nice! I'm thinking about putting one of those LED headlights on mine. I have one on my XL70 rat jalopy.
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  13. ArdenLoneWolf

    ArdenLoneWolf Been here awhile

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    Just got a lifan 125 mounted on my CT70, started right up, need to finish putting back together but super stoked on this thing. IMG_20190520_181721287.jpg
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  14. Oscarjp

    Oscarjp n00b

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    looks great, shiny! i see you got Shinko tires on your other bike, i got em on my triumph. about to put my second tire on the rear after 8K miles!!!
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  15. iatethepeach

    iatethepeach Been here awhile

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    Hey everybody. Although I've read through this excellent thread a couple times, I'm still having trouble selecting an engine for my CT90 restomod. Primarily, I've noticed a few complaints about difficult shifting with the 1-down, 3-up pitbike motors elsewhere on the internets. This is the model I have my eye on right now. Are they really any worse than your average 60's/70's Honda? What's the deal with the proliferation of 4-up horizontals, anyway? My bikes sometimes have a minor hiccup, but it's infrequent enough that I find it more charming than annoying. My gf might be piloting this thing once in a while, as I try to get her into motorized riding; I don't want to frustrate her. Should I just go with the flow and get a 4-up?

    Thanks!
  16. WECSOG

    WECSOG Dirt Road Denizen

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    That's what I thought, too. My advice: go with the flow. I usually had to kill my 1D3U engine to get it into neutral.
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  17. pnw

    pnw Long timer

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    I'm happy with my manual clutch 1 down 3 up Lifan but if I were to do it again I would probably go with the 4 up semi auto which would probably be better in your case with a learner rider. Neutral can be hard to find on the 1 down/3 up. The semi auto also allows you to keep the left hand rear brake lever instead of substituting a clutch, or add a left hand rear brake lever if your CT doesn't have one.
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  18. Oscarjp

    Oscarjp n00b

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    go with the flow, my 4 up is nice! get a 140, you won't regret it, it might sound like too much but keeping up with traffic is nice. ;)
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  19. hugemoth

    hugemoth Big Brother is watching you!

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    I agree with Wescog, my 140 is 1d3u and is usually hard to find neutral. 4 up would be better. The 140 is great though except for requiring a strong leg to kick it over.
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  20. Oscarjp

    Oscarjp n00b

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    if the 140 is hard, then get the lifan150cc 4up, starts up in 1 2 kicks easy, that's what i have and runs great.
    iatethepeach likes this.