Should I get a 50cc motorbike?

Discussion in 'Off Topic' started by Ollie, Dec 13, 2013.

  1. Ollie

    Ollie Member

    Hello all,

    After some disappointment with the poor quality of local bicycles and components here in Brazil, I've started looking into a 50cc motorbike for daily use (I'll still have a couple of 2-stroke MBs for my hobby). Vehicles with 50cc or less fall into the same category as motorized bikes and therefore require no license, insurance or registration. I've only recently started familiarizing myself with petrol engines and I have sparse knowledge of motorbikes in general. Here are the specifications for the bike I'm looking at, does anyone have any wisdom to share about whether this sounds OK?

    Single cylinder, 4-stroke, OHC, air-cooled
    Displacement - 49.5 cm ³
    Max Power - 3.2 hp at 7,500 rpm
    Maximum torque - 3.1 Nm at 4,600 rpm
    Bore x stroke - 39 x 41.4 mm
    Transmission - Semi-Automatic (4 speeds)
    Dry weight - 85.65 kg
    Electric start and pedal system
    Fuel tank capacity - 10.4 liters
    Engine oil capacity (after draining) 0.8 liters
    Ignition Capacitive Discharge Ignition (CDI)

    Attached Files:

    Last edited by a moderator: Dec 18, 2015

  2. grinningremlin

    grinningremlin Active Member

    I can't see any pedals, but it looks like a nice little motorcycle.
  3. darwin

    darwin Well-Known Member

    If I were to get such a beast I don't think 50cc would be adequate enough for driving in traffic. For me a 150cc or at a minimum a Yamaha 125cc would be the minimum size. 50cc bikes/scooters just don't have the oomph to drive in traffic, plus if you weigh 200lbs or so it's even worse. Anyways just my 2 cents. Next year a 250cc bike or a 125/150 scooter is on my list.
  4. Ollie

    Ollie Member

    @grinningremlin - No pedals, sacrilege I know, but I desperately want something strong enough to support a passenger.

    @darwin - I've been using an MB in city traffic and it's able to keep up most of the time (congestion is common here, which suits me, and traffic rarely goes above 30mph). If the laws were different I'd get an 80-100cc, but I don't want the additional cost (and horrendous bureaucratic process) that comes with the registration and insurance of a bigger engine.
  5. grinningremlin

    grinningremlin Active Member

    No sacrilege, I just saw "pedal start" in your description, the pic was loading slow (dial-up luddite) and I was saying to myself "come on modern moped!" and it turned out to be a motorcycle.A man hast to do what a man has to do, and I fully understand the want for passengers, you live in Rio, the women,... THE WOMEN!A moto is going to be much nicer in that regard, shocks, gears.If you have the income I say go for it.
  6. Ollie

    Ollie Member

    I translated the description directly from Portuguese; a better translation would be 'kick start'. I saw a cool little moped the other day, but an internet search of the name came up with nothing. It might have been a custom one or an old one that was refurbished. In hindsight I should've taken a photo. I'm newly married with a Brazilian wife, so although I'm not on the prowl it's nice to be able to take her places. I went to the showroom today to check out the motorcycle, liked it a lot and made the first payment; it should be ready to collect on Friday! :D
  7. wheelbender6

    wheelbender6 Well-Known Member

    A 50cc machine works good in areas with speed limits around 30-40 mph. That's about the best looking 50cc machine I've ever seen too!
    On roads with speed limits of 45mph and above, my 50cc bike wasn't fast enough to make me feel safe.
    I have a 125cc scooter now and it feels safe on roads with speed limits up to 50mph. The 125 is not really fast enough for speed limits over 50 mph.
    ***I did have a thought. You could buy that great looking 50cc bike and replace the Honda clone motor with a 110cc Loncin or 125cc Lifan motor.
    Should be a bolt-on or near bolt-on job.
  8. Ollie

    Ollie Member

    I've found a route to work where the speed limit never goes above 60km/h (37mp/h) so that should work nicely. I agree, it's a beaut! It's the new 2014 version; the old one looked really basic. I'm keen to keep it fully legal, so I'll stick with the original engine for now. Is it really that easy to swap out engines? I didn't think they were that standardized.
  9. wheelbender6

    wheelbender6 Well-Known Member

    For roads with a 37 mph speed limits, I would stick with the 50cc mill and enjoy the fuel savings.
    I was restoring a Honda S90 a few years ago (same type of engine with horizontal cylinder). I joined a Yahoo
    group that explained how to upgrade to a larger, similar engine. Upgrading from a genuine Honda engine to a Loncin
    or Lifan required drilling new holes in the frame or slotting some existing holes and rewiring. Upgrading from one Chinese
    horiz engine to another Chinese horiz engine should be far easier. Many have done that swap on a Sachs Madass (50cc to 125cc).
    There are some pocket rocket forums that should have some info on that swap.
    It's good to know what is involved in that engine swap in case you take a different job and need to drive on roads with higher
    speed limits.
  10. Ollie

    Ollie Member

    Cool, thanks for the info. I've got a distant plan to make a dirt bike out of it. I'd like to strip it down to bear essentials to reduce the weight, get some longer suspension and fit some knobbly tyres. A larger engine at that point might be cool too. I imagine it looking something like this afterwards, but with lights and a motocross front fender:

  11. HeadSmess

    HeadSmess Well-Known Member

    all these china 50's share the same engine bolt pattern as the larger sizes...

    so,,,you get a 50 frame. and then find either... a lifan 140 (IP55), 150 or a YX/jailing 150/160...

    the lifan 140 is about the best bet. needs at least a small jumper on the oil cooler lines. sticking an oil cooler on does look cool :)

    really, youre best off to try and find a second hand C or SL 50 or 70. much more common and free of import duties if its already in the country... preferably the C if you gunna chop it, the SL is a collectors piece!

    the honda 90 and 110 do NOT share the same bolt pattern as the 50, 70, or any china motors. dont get fooled!

    theres also plenty of upgrades on the china stuff...hi lift cams, hi compression pistons, over sized valve heads, twin cam heads if you got the money... and a 5 or 6 speed box for the 150 size... once again, money for having more gears than standard :)
  12. Ollie

    Ollie Member

    Thanks for the info, are these engines or bikes you're referring to? And what's the name of the company that makes them?

    Edit: I found out what you were referring to, the SL70 is exactly what I hope to make out of this 50cc. Here's a beautiful example:
    Picture 2.jpg
    Last edited: Dec 16, 2013
  13. HeadSmess

    HeadSmess Well-Known Member

    something like that. note that it has the yx 150 engine ;) or 160 even?

    no way its a daytona 125...the only other option with that type case!

    honda! sorry...yes. erm, ok...but.

    what i was saying, is that any HONDA C50 or 70 type frame (xr50 and 70 even...) will readily accommodate a "china" style engine, even if it is a daytona with a $1500 price tag! (thats AU).

    the standard lifan 140 can be bought for $300... then again, finding them in brazil maynt be so easy?
  14. Ollie

    Ollie Member

    Nothing is easy in Brazil! I'll stick with the 50cc for now and try and make it more suited to off-road. I'll keep an eye out for a larger Chinese engine though, I like that fact that it won't need any welding or major structural modifications to fit. I'd be cool if I was able to swap the engines in a relatively short time so I could have the 50cc for legal commuting and then take it out to the country in the back of a van with the bigger engine for some scrambling.
  15. Ollie

    Ollie Member

    I collected my motorcycle yesterday and I've been riding it at every opportunity; offering to run errands and pick up shopping just for an excuse to ride it. It's really smooth compared to my 2-stroke MB thanks to the suspension, but the acceleration is much lower due to both the weight and the fact that it's a 4-stroke. I think the engine has been restricted to 30mph, because after that it starts to lag even though the engine sounds like it could rev higher. I may look into de-restricting it in the future, but I'll wait until the 1-year warranty has run out before I start tinkering with it.
  16. wheelbender6

    wheelbender6 Well-Known Member

    Great looking bike. They would sell more 50cc bikes if they looked that good. Keep it locked to something strong with a cable so it will not wander off.
  17. Ollie

    Ollie Member

    Thanks, yeah, I'm using a bicycle cable lock right now but I'll invest in a proper motorcycle one soon.
  18. darwin

    darwin Well-Known Member

    Hard to see what kind of breather setup you have on that, but if I'm correct from the looks of it it's restricted. Try running it unhooked and see if it improves performance. If it does get one like a K&N setup to improve the airflow. I wouldn't ride it too long w/o a filter on it but just to test it.........there's a lot of steel in that bike for a 50cc, nice bike though.
  19. Ollie

    Ollie Member

    Hi Darwin, thanks for the response, but I'm unfamiliar with the terms you're using. What's a breather, and how do you unhook it? I agree there's a lot of steel, the thing weighs a ton. Here's a close-up if it helps your analysis:

    Picture 2.jpg
  20. HeadSmess

    HeadSmess Well-Known Member

    that silly thing stuck there with all the hoses...they put that on for emission controls... is the "breather". there should ALSO be a hose somewhere near the BACK of the engine...)

    at most, you can just run a hose from the rocker cover (on the engine where that hose starts) to the airbox (where the other hose ends), or just forget about the hose altogether, they dont put them on when they run on dirt!

    gets into catch cans and so forth, cus they spray a bit of oil...

    its simply a compliance thing for registration and emission standards, directs oil vapour back into the engine, and liquid oil back into the crankcase.

    if you pull apart your intake system, from aircleaner to where the carb bolts to the engine... youll more than likely find several "restrictions".

    from gaskets to spacers to manifolds... its called "port matching".

    change airfilter to a K&N (or unifilter, etc) "pod" type filter, they breath! (dont do it if you ride in the rain a lot)

    the carb should be about right for a 50, but will need rejetting after changing the air cleaner. once again, sort of the wrong forum board now... try anything to do with "pitbikes" "minibikes" "monkeybikes" or "honda 50's", and you will find a wealth of information!

    and then, theres usually a bit of restriction in the exhaust... pop it off, blow through it, if its not like blowing through a hose pipe...find out whats blocking it and pop it out! will be LOUD afterwards. and again, need rejetting at the carb for the extra airflow.

    it will also pop wheelies, and still be 50cc and perfectly legal :) even a little 50cc can get up to 80Mph or more! (144mph is the world record for a 50)

    here, they HAVE to be capable of 50km/h minimum to be compliant. (im in the wrong part of the country to NOT need registration :()

    then you can think about cams... if all that didnt cause a big enough grin of satisfaction ;)
    Last edited: Dec 27, 2013