Discussion in '4-Stroke Engines' started by jtbarnes89, Oct 3, 2010.

  1. jtbarnes89

    jtbarnes89 Member

    has anybody mounted a crf50 motor on their bike?

  2. jtbarnes89

    jtbarnes89 Member

  3. 5-7HEAVEN

    5-7HEAVEN Guest

    Probably not.

    Can you give more specifics on this engine and the bike it came off of?:detective:

    FWIW, the 2hp 50cc Lifan clone engine/trans weighs 42lbs. There are lighter engine choices, like a 4.2hp GP460 engine, which weighs about 7 lbs.
    Last edited by a moderator: Oct 14, 2010
  4. jtbarnes89

    jtbarnes89 Member

    HONDA 2004 crf70 motor and trans its a four speed with no clutch
  5. HeadSmess

    HeadSmess Well-Known Member

    heavy. illegal. sorta a daft idea.

    what sorta brakes you intend on using?

    frame? wheels? drive system?

    sure... kill a perfectly good feefee, but um...why? you end up with a bigger, flimsier or heavier, crf50...
  6. ccpomea

    ccpomea Member

    Illegal in what way?
  7. HeadSmess

    HeadSmess Well-Known Member

    illegal as in what country are you in, and where are you going to ride this thing?

    here? i wouldnt be getting my license back til 2020 if i got caught riding one of them on the road....

    now if your in india, its different, innit?
  8. ccpomea

    ccpomea Member

    Based on him mentioning a CRF50 I would assume he means the stock engine, which is 49cc - just as legal as any other 49cc.
  9. JunkyardDog

    JunkyardDog Active Member

    First he said a CRF50, then a CRF70. A CRF50 would be legal, as long as you keep your speed down. In AZ, where motorized bicycles are legal, they have a max displacement of 48cc (that's 48cc, not 49cc) I'm riding my 49cc Solex as a motorized bicycle, but if I were ever involved in an accident, and the police or some lawyer started checking, they would find out it is not a legal motorized bicycle. A Solex is fairly well known, and everyone who knows anything about them knows they are 49cc. My guess is a CRF50 is also 49cc.

    As far as making it work, anything can be done, but why? There are so many other engines out there that are far more suitable as a bicycle engine. How and where would you mount it, what kind of drive train would you use, and being a 4 speed, how would you shift it? Also, since a CRF50/CRF70 is an MX engine, they make a lot of power for their size, and tend to be really peaky. You would need a strong heavy bicycle to mount it on. Jerry.
  10. HeadSmess

    HeadSmess Well-Known Member

    yep, here, 49 cc is legal too.

    as long as its registered. which involves VINs.. money...paperwork...

    oh, and you also need a license... unless i move state, then its just the rego.

    and you arent going to get a bicycle with a crf50/z50/xr50 engine strapped onto it registered.
  11. ccpomea

    ccpomea Member

    For reference I'll quote the original comment I was responding to -

    The blanket statement of "illegal" is incorrect, it all depends on his state and his desired use.

    I needed all that (VIN, driver's licence and registration) just to make my "HT" 49cc engine road legal.

    I was also able to register my Motoped DX the same way, which has a 49cc Honda Z-50/XR50/CRF50 clone engine.

    However, even if I wasn't able to register it, I could still drive them on my own property as there is nothing inherently illegal about them as your first quoted post suggests, as even if it isnt able to be registered or make roadworthy there are then just legal and illegal uses.

    I find it odd how people install a 66cc Happy Time style engine and get the advice here... "they wont realize its 66cc, just say its 49cc", but when someone mentions a crf50 engine it's automatically dismissed as illegal without any context being applied to it.
  12. HeadSmess

    HeadSmess Well-Known Member

    ok, ok, context being that the crf50 engine has gears and is intended as a motorcycle engine.

    yes, i feel the same way about the 49/66 issue, and always tell ppl to go small, just for the legal implications.

    while im saying this, in australia, or nsw at least, the rules have relaxed somewhat.

    it is now legal to ride anything with a capacity over 30cc(where there WAS a limit, there is NOTHING NOW!)
    it is now legal to go over 30km/h(once again, nothing!)

    it is all legal as long as you DONT exceed 200 watts... which is about an athletes output...

    so even a HT is highly ILLEGAL here.

    (my dream is to flaunt these rules, and find a way to get, say, a chev 350 restricted down to that output... cus, it WOULD BE LEGAL! as long as its fitted to A BICYCLE DESIGNED AND INTENDED SOLEY FOR HUMAN POWER{mopeds need registration and licenses})

    so, yes, laws are different in every area. thats why you search your local laws.

    but i still think a crf50 engine on a pushie is completely stupid. cus i have several of them and wouldnt ever do that to one!
  13. JunkyardDog

    JunkyardDog Active Member

    In AZ, any motorized bicycle with an engine displacement of 48cc or less is considered a bicycle, no paperwork, registration, nothing. I have noticed that most all the HT engines are 48cc. Mopeds are a whole nother matter, and where things start to get complicated. First of all, a moped must be factory made (like Tomos, Puch, Peugeot, etc. It must have a factory VIN. It must have an engine of no more than 49cc, and be capable of going no faster than 30 mph. It must have factory installed functional pedals. Remove the pedals, and it becomes illegal. Mopeds must be registered, but have no title, like a motorcycle. They must have a plate, which says "moped" on it, and insurance, and the rider must be at least 16 and have a drivers license, but not a motorcycle license. Now this is where it gets a bit crazy. Take the exact same bike (Tomos makes both versions of all their models) with pegs instead of pedals and a kickstart. At that point it becomes a motorcycle, has a title, a motorcycle plate, and the rider must have a motorcycle license. Yet except for the lack of pedals, it is the same as a moped, still 49cc, still has a 30 mph top speed, only now it must be ridden out in traffic, not in the bike lane like a moped. No 30 mph motorcycle is going to be usable in the traffic around here, you would get squashed like a bug. So if you're buying one of these in AZ, make sure you get the one with pedals. Jerry.