Best way about going from 2 stroke to 4 stroke

Discussion in '4-Stroke Engines' started by davidtuerk, Jul 8, 2014.

  1. davidtuerk

    davidtuerk New Member

    I have a 2 stroke kit currently installed on my bike, But the engine keeps blowing up, So I want to change it over to a 4 stroke. I should only need a Engine, Mount and a gear box correct? What would be the best way of getting these parts. I am in Ontario so closer is better in terms of shipping.

    Thanks in advance!

  2. darwin

    darwin Well-Known Member

    1st decide what motor/kit you want, then check out vendors/ebay to see where you want to buy. Seems a 49cc HS kit is what you need. Then deciding on the transmission is important too.
  3. davidtuerk

    davidtuerk New Member

    What transmission would you recommend?
  4. darwin

    darwin Well-Known Member

    No one can decide for you, You need to decide..............good luck!
  5. darwin

    darwin Well-Known Member

    After thinking about your ? folks have nothing but good things to say about the Qmatic transmission. Use search a lot of info should pop up.
  6. Fabian

    Fabian Well-Known Member

    A 2-stroke engine is weighs less and is easier to work on and is just as reliable as a 4-stroke if fitted with a Jaguar CDI and the carburettor is jetted correctly.
    My last 2-stroke engine ran for 10,000 kilometers (6,000 miles) on the bottom end. I typically get 4,000 kilometers (2,500 miles) out of a cylinder, of which the piston can be reused.
  7. KCvale

    KCvale Motorized Bicycle Vendor

    The 49cc HS 142F with 20T/80TFW/12T Grubee 4G belt drive transfer case is pretty solid.

    Unfortunately it is only like $15 cheaper to just buy the engine and 4G transfer kit than the whole $350 4-stroke it, but you do end up with a lot of spare parts which is always handy, around here anyway.

  8. seanshonda

    seanshonda New Member

    ??? what 4 stroke are you comparing w/? I've been running a Honda gxh50 since '07, 6000+ mi, aside from oil changes & cleaning air filter, I've done nothing to it. well, I did have to disconnect the oversensitive low oil shutdown, im oldschool, so I check oil anyways.
    if you buy a clone, you get what you pay for. its just like a Honda, but different. theres a reason Honda doesn't contract them to build their engines.
    from what I've heard about 2 strokes (rawlyold), tanaka purefire engines are tough & trouble-free.
    the Honda 50 & tanakas cost $350-400 new, but they last at least twice as long, so the cost compared to a clone??? I like to know that the only thing that's gonna stop me is a flat or running out of gas---that'll stop a clone too.
  9. davidtuerk

    davidtuerk New Member

    I've only had/seen one 4 stroke blow up ever, and It was my Yamaha Apex 1000CC Snowmachine, tossed a connecting rod cap through the crank case. And that was a stupid high revving engine (10,500RPM+). I'd like to get a actual honda but they are just so damn expensive and really I will be only driving my bike for another year or two then I will have my G2 Drivers licence. I could just replace my entire 2 stroke engine for about $145 but I'm not sure if I should do that because it might just be another lemon.

  10. seanshonda

    seanshonda New Member

    10,500rpm? I doubt they had the motor rebalanced after the mods.
    how many miles do you get for $145? Honda 50s were $330 shipped in '07, almost $400 now.
    how often did you have to adjust the carb, etc.? I never took my Honda to shop for adjustments after break-in even. clutch pads & drums, oil change, clean air filter, that's all ive done in 7yrs w/ a Honda, need a new friction roller-getting bald, but that and clutch parts aren't Honda.
    im sure you could resell a Honda for good money, I buy for reliability. I don't want to be 50 mi from home and have a break down, bum knee wouldn't let me pedal nor push bike back in under 3 days!
  11. HeadSmess

    HeadSmess Well-Known Member

    i dont like the huasheng 50 anymore. seen three die. my first post here was to see if anyone knew what was up with the stinking thing, cus even after swapping carb to a mikuni slide, i couldnt get one to run nicely. a year left to rot out in the rain, and it changed its mind!!! still required a new carb but.

    but i does like my li honda 25 on my brushcutter. faultless :)

    i also like my huasheng 25's which are mere copies of the fuji robin.

    i liked my hyosung 650 until...i just sold it today :( 120,000km + :) not bad for korean :)

    but, my only, and really, its my ONLY gripe with any 4 stroke...they just arent designed for fitting to bicycles. not a definite, this is SOLELY for bicycle motorisation engine exists, other than the 2 stroke HT, or other similar type engines. they have been around since the 30's. 20's even.

    oh. except for the whizzer 4 stroke engine! that WAS designed for bicycles!

    but i shant discuss them, having never seen one in real life, therefore absolutely no experience with them.

    someone needs to design one with DOHC, 50cc that will tear the pants off of ANYTHING else available :) a lil engine like that, if honda designed it, could sit at 16000 all day long!

    it will also be expensive :( the whizzer is...
  12. Fabian

    Fabian Well-Known Member


    If only Honda would make a replica 2-stroke Chinese motorized bicycle engine but manufacture it as a 4-stroke using a super sexy RCV sleeve valve gear reduction design:banana:

    As compact as a 2-stroke with almost the simplicity of a 2-stroke, yet having the reduced noise and reduced exhaust sensitivity of a 4-stroke.

    Last edited by a moderator: Dec 15, 2015
  13. seanshonda

    seanshonda New Member

    I keep getting replies about people having good luck w/ clones, usually after modification and usually silently tweeking their set-up w/ a new carb and cdi, not considering the time they spend adjusting---read on here.
    aside from marine engines, my experience w/ 2stroker was a '02 Yamaha vino (2), also had '05 vino(4 stroke), the '02 had its exhaust deregulated, at red lights I would gun it (watching cross traffic signal I would time when to go) and vehicle next to me would have to floor it to keep from having a scooter out accelerate them, very funny to see. but when it came to hills, the stock 4 stroker would hold speed a lot better. from my experience on those scooters, one 2stroke (oil injected, no mixing) the other a unmodified 4stroke, I still opt for the 4stroke.
    as far as I know, there are no reliable engines that were built for bikes. a 16k rpm 4stroker would need an intercooler like a turbo engine. yeah, big$$$, I'm getting flak for recommending a super reliable $400 Honda!
    tanaka used to make a 47r 2stroke that spun @12 or 14,000rpm, hard to find now though. w/ my setup, that would be 55-60mph!
    btw, I do love the smell of 2stroke exhaust, not as much as gunpowder, but close.
  14. HeadSmess

    HeadSmess Well-Known Member

    ahhhh, youve finally found out about the RCV? is a beautiful design. especially the SP with its already reduced output shaft :)

    so much nicer than the napier sleeve valve design, which is a rather strange system, but was reliable enough to feature on many early aircraft engines.

    they themselves started a 125cc prototype, based on the honda cub, aka ct110 type engine.

    when i emailed them several years ago, the response was...

    damn. no matches found! musta deleted it! i recall deleting the main contact just the other day too! getting rid of all these one time contacts. grrr.

    anyway. they told me they had sold most of the rights to the military, for UAV/drone engines. that the prototype was no longer being considered as viable.

    but then last time i checked their website it appeared i had been lied to?

    have go at contacting them. maybe theyll tell the truth this time...

    hope you got a lot of financial backing ;)
    Last edited: Jul 24, 2014
  15. HeadSmess

    HeadSmess Well-Known Member

    mmmm, gunpowder :) real, oldschool blackpowder or the modern alternative?

    when i had a pitbike/thumpster road registered and capable of doing 120km/h on the flats due to a lifan 140 and some cams... i was ALWAYS beating ANY bike at the lights....simply because they was so busy laughing!

    then, 100 metres later, just as i was hitting 4th...they would fly past on the rear wheel, still in first, hoping i wouldnt see their red faces :jester:

    i really really want a nsr 150-250 so i can make it some pipes. never had a 2 stroke road bike :( or that old yamaha twin 200 a friend had.

    stupidest thing i ever saw was some idiot that had strapped an AMR300 supercharger to a scooter... (AMR? the tiny ones!) what a waste of supercharger! his pod had been half scraped off on the road, and...just...what a waste :(
  16. Fabian

    Fabian Well-Known Member

    I just love the sleeve valve design and it's the logical method of operation.
    Poppet valve design is an utterly stupid concept when compared to a sleeve valve system, and imagine where piston engine design would be if the sleeve valve method had 70 years of mechanical and materials development, particularly an electronically controlled and operated double sleeve valve system - ohh la la :drool5: i want some of that.
  17. darwin

    darwin Well-Known Member

    You guys are not mentioning the EPA factor in deciding which motors can be sold here, they're like gods.
  18. HeadSmess

    HeadSmess Well-Known Member

    oh yeah...nasty b***ards... unfortunately with 7 billion of us happily breeeding away with no thought of the consequences...the EPA is just a small blip on the radar. no concern to most... we're all doomed regardless. but we have to start somewhere.

    the whole topic deserves its own thread, maybe the mods can do something about that... "sleeve valve options" would be a nice name, i guess.

    fabians post was rather a case of thread hijacking after all, and was as much help in this situation as mine was...


    ^^^ the RCV 35cc 1.8kw answer to the gx35. ^^^

    meets EU2 regs. 2.5 horsies!

    can rev faster than any standard gx35, with no fear of destructive piston to valve contact, no possibility of valve bounce, no excess power consumed by compressing springs. is extremely simple, with a minimum of parts. higher compression with lower octane fuels. lightweight. not yet in production :(

    maybe, with a new thread, outlining the requirements desired in our area of (sadly overlooked) motive power, filled with enough responses...a petition if you will... a company such as RCV and, say...huasheng, could get together and work on a high-production-volume-so-relatively-cheap, FOUR STROKE engine specifically for motorised bicycles.

    just a thought? ;) sleeve valves were good enough for rolls royce' last piston engine they developed(the eagle II i believe, just before the turbine took over, not too mention the hundreds of variants used in other aircraft at around the same time...), and are renowned for simplicity and why are they no good for other applications?