Honda 49cc 4 stroke maximum speed

Discussion in 'Performance Mods' started by sexwaxsurfer15, Apr 10, 2008.

  1. Im new so please bear with me. I am going to put a 49cc Honda on a beach cruiser. What tooth count do I need to get the max amount of speed. Does it work by the less teeth, more top speed and vice versa? Also, is 35-40 mph a realistic speed for this engine and application. Thanks

  2. kawasaki999

    kawasaki999 Member

    smaller on the wheel increases speed.
  3. Demosthenese

    Demosthenese Guest

    do some home work friend, all your answers are here and there is a search function now that you are a member.

    35-40 is attainable, but not necessarily advisable or legal. The less teeth on your rear sprocket, the faster you will go. You will see about a 1 mph increase per tooth lost apparently, so from the stock 44 tooth that ships with most kits down to the 36 tooth that is generally the smallest sprocket most people run, you will see about an 8 mph increase in top speed, but a probable decrease in acceleration. A stock 49cc may not be able to go quite that fast without things like a tuned muffler or an aftermarket carb, but there are lots of people who have gotten pretty fast using a variety of techniques; look arround the site and you'll find lots of options.
  4. sparky

    sparky Active Member

    I assume you mean smaller sprocket on the wheel increases speed... because that'd be true.

    A smaller wheel decreases top speed as each rotation has less circumference to touch the ground.
  5. HoughMade

    HoughMade Guest

    A smaller sprocket on the wheel gives a theoretical increase in speed, but you need to keep the engine in its power band. You could end up putting on a sprocket that is so small that due to weight, friction and wind resistence, you could not coax the engine to run where it makes power.

    With a Honda GXH50- I'd give a 48 tooth a shot if top speed is what you are looking for and see where that gets you (depending on the gearbox reduction).
  6. I like my 44 tooth sprocket cause to me what's most important is the crowd lol when I pedal ever so slowly then when I release my clutch my engine starts ever so gracefully and I pull away ever so cooly. :cool:
    If you want to go faster than 20 mph on a bicycle it can be done. Turbo does this on a daily basis. But you'll be just as cool going down the beach just for the fact that you're not pedaling.
    Get a motorcycle if you want speed. You want cool? Cruise.
    I say put on whatever sprocket your kit comes with. It's usually a 44 tooth. Some suppliers come with a 50. That may be too steep.
    Try out the 44 for a while then ask yourself if your willing to compromise torque for speed. Then get a 36 tooth.
    Last edited by a moderator: Apr 11, 2008
  7. sparky

    sparky Active Member

    I would also start with 44t & slowly work my way down.

    You might also consider a gearbox or a NuVinci hub. Whenever I get a new engine, I'll be getting the NuVinci hub, too. You can find a video on it w/ other useful information here:
  8. HoughMade

    HoughMade Guest

    Remember, guys, this is about a Honda 49cc- a 4 stroke- the power band and the gear reduction (depending on what box is used) is not the same as a 2 stroke- In my view, a 44 tooth would be the smallest I would ever want with the Honda and Grubee Skyhawk II- which is what I have. I get over 35 mph with a 56 tooth and with a 48 tooth, 40 mph should not be a problem. A sprocket below 44 may take the Honda right out of its power band and prevent it from revving to where it is happy.

    However, as I said, it's dependent on the gear reduction- with a different ratio, a different sprocket may be required.
  9. Oh my bad. I was just assuming a Happy time. I see that little part in that post now.
  10. bicycle ron

    bicycle ron Member

    I know you guy's like the 2 stroke engines, but I cruise to the beach every weekend on my bikes with freinds on 4 stroke stretch cruisers w/ no problems! I agree with LARGE FILIPINO! Enjoy the ride! Relax, have fun, no matter what you ride! I have 5 cruiser's w/Subaru 33 cc engines and they run about 32 MPH! I love them. I have never had problems, except minor adjustments! I really use a turkey baster to pump out my oil! Not really, It was a thought! I unscrew my cap and turn my big *** bike upside down and drain into a old kitty litter box and take to jiffy lube, and they despose for me! Buy the way, my 33,cc engine goes 30,to 33 on friction drive, and I have done some custom drive mount displacement,and observation, and adjustments here and there,and I have never been pulled over,[thank god], But they're is someone I always see with a mid mounted 2 cycle engine at the store that has already had 4 tickets for riding this bike on Florida roadways! My engine is not mounted mid frame, and is mounted on the left rear side in cognito! Even with that, I have been at red lights with the man [not Sam The Man] and the look and wave!!! Ya think maybe because I'm NOT trying to make it look like a real motorcycle???, or Like the Large Filipino say's: Enjoy your ride!!!! It's a bicycle! When I can afford a Harley, I'll still do bikes!!!
  11. stude13

    stude13 Active Member

    gears-sprockets-chains OH MY try a gebe kit, kevlar belt, plastic drive ring. im 250 and get 28-30mph and 200mpg with a honda 35. rideon stude13
  12. sparky

    sparky Active Member

    wise decision...
  13. mholder

    mholder New Member

    new 2 this

    i have ebay kit i put it on genessis onyx bike w 29" wheels, i weigh about 250 and get about 29mph on my bike is that good for 49cc 4 stroke
  14. sparky

    sparky Active Member

    Sounds about right to me.

    Only missing variable is the drivetrain, which I'm assuming is chain-driven. Soo... what's your gear reduction like?

    Gear reduction is the number one way to affect acceleration and top speed... by a very, very wide margin.
  15. Ricky 2316

    Ricky 2316 Guest

    What's faster a 2 or 4 stroke?
  16. 5-7HEAVEN

    5-7HEAVEN Active Member

    4 stroke.

    4 is bigger than 2.
  17. Carlos motors

    Carlos motors Member

  18. Steve Best

    Steve Best Well-Known Member

    Sheesh. I think 5-7HEAVEN it trying to be funny.

    2 strokes fire twice as often as 4 strokes, so all other things being equal (rpm, size, state of tune), they usually make more power.

    Things are rarely equal.
    A 50cc 4 stroke (especially Honda) is good starting, reliable and torquey but is not known for great power and speed.
    Honda rates their 50cc utility motor as making 2.1 HP:
    The Honda 50cc Cub motorcycle engine could make as much as 4.5 HP, but it is a completely different )OHV design running at high rpm (9500).

    To make more HP with a 4 stroke is a complicated and expensive task. It generally starts with a camshaft purchase and due to rpm limitations (from basic crank and connecting rod design) it is very hard to get more than a 50% increase in power.

    HP = speed (all other things being equal) if you have the right gearing and conditions to use it.
    A stock 48cc Chinese 2 stroke puts out about 1.95 HP according various sales sources. Roughly the same as the Honda 50.
    I'd say this is is accurate. If anything, the 48cc Chinese 2 strokes are de-rated to fit with many countries max HP laws.
    Fitting a tuned exhaust pipe and different cylinder head will usually see a 50% increase in power. A 150% increase in power (3-4HP) is easily and cheaply attainable with porting and pipe work. I was able to get this much HP with only porting, head work (on the stock head) and a $20 stock (but non-catalytic) muffler.

    2 strokes are not for everybody. While a 2 stroke is typically smaller, lighter and cheaper to purchase, they typically require care with the fuel/oil mix, are smokey and often drip oil, and require mechanical and tuning ability to properly jet them for best performance without having them self-destruct. 4 strokes burn clean and are not as dependent on tuning ability for good performance as delivered.

    Long answer to a simple question. I hope it puts things into better perspective.
    Last edited: Jul 26, 2017
  19. 5-7HEAVEN

    5-7HEAVEN Active Member


    Steve explained it very well
  20. CrazyDan

    CrazyDan Active Member

    Jeez how do these guests always revive ancient threads lol?