Reliability...2 vs. 4 cycle engines

Discussion in 'General Questions' started by Capitol Motorbikes, Jan 22, 2008.

  1. Hi All,

    I have been running a 70cc 2-stroke kit motor from ebay for the past month or so. These are a lot of fun, but need lots of TLC. This morning, the rear wheel locked up suddenly and caused some serious road rash. Can any of you tell me which motors (2 or 4 stroke) are the most reliable?:?:

  2. Alaskavan

    Alaskavan Guest

    Just my opinion: I think 4-strokes are more reliable, I also think Japanese manufacturing is superior to Chinese.

    P.S. I think there is already a thread comparing 2-stroke and 4.
    Last edited by a moderator: Jan 22, 2008
  3. fetor56

    fetor56 Guest

    I gotta agree with van...if u take everything into concideration 4-strokes are superior, it's just that 2-strokes are more compact and hence lighter.
    Just about any country is better at manufacturing than the Chinese.I don't blame them...i blame our Western manufacturers who go overthere and say "how cheap can u make this".Their own "non-branded" items are also inferior(but cheap)
    As for 2 or 4 it's a pretty personal decision...i love my HT 2-stroke,it's never let me down but i'll be swapping over to a 4 just as soon as i can get the parts........that's my personal decision.
  4. capitol how did the back wheel lock? did the drive chain fail, or engine sieze? hope your road rash heals quik
  5. Other than initial install problems and loosening bolts (which have since been taken care of)
    my HT engine seems fine.....I haven't experienced too much with the 4 strokes but I hear
    they are possibly more reliable then the 2 stroke HTs.....I like look of the center mounted HT better than the 4 strokers tho.

  6. Jim H

    Jim H Guest

    4 stroke = more moving parts...maintenance of valves, frequent oil changes; no biggie to me as I like them both equally well.
  7. iron_monkey

    iron_monkey Guest

    The 2 stroke engines dont need tlc, they break because people abuse them by running them at speeds/rpms well above what the engines can take.

    Although the manufacturers are also to blame as the stock sprocket is simply too big which simply makes widespread abuse unevitable.
  8. chuck1980

    chuck1980 Member

    Sure wish you would have explained what caused the wheel to lock up. For someone like me considering either a 2 stroke or a 4 stroke, it's a real setback to make a quickie post like that and run off.
  9. fetor56

    fetor56 Guest

    Unusual isn't it....perhaps he went away on hols or is sick.
    I can only speculate it's something to do with his chain tensioner,causing the chain to jump off the rear sprocket then the chain wrapping itself around the countershaft sprocket, causing the engine to stop suddenly.
    I guess we'll never know this mystery...this who done it.....this MBc own Bermuda Traingle.
  10. kerf

    kerf Guest

    My opinion:

    Two stroke vs four stroke:

    A quality two stroke engine is as reliable and rugged as a quality four stroke. There are differences in weight, power curve and torque curve but those things taken into account, little difference. It's not unusual to find 50 year old two stroke outboards still running with no rebuild.

    Chinese engines:

    Don't blame them or the western manufactures for poor quality, when we're buying all they can import. The marketplace is the final judge on what quality is produced. If a US manufacturer built and offered a high quality bike motor kit for $1500, how many of us would be in line to buy one?

    Thoughts of a grumpy old man.


    My aim is to make the strongest bike motor on the planet, you could get on it and ride fifty miles in under two hours, no disrespect to the two stroke guys.

  12. kerf

    kerf Guest

    I have a two stroke that will do that and more without a trailer. So what?
  13. Sorry to bolt on you guys. The rear wheel locking up had nothing to do with the engine, just a fender malfunction (it got bound up between the wheel and frame).

    Any advice on keeping the fender mounts from breaking?
  14. azbill

    azbill Active Member

    change the fender mounts to "L" brackets from the hardware store
    grind the rivets off and use bolts/locknuts
    (a trick I learnd from SrDavo :D)
  15. Why didn't I think of that?

    Brilliant and sage advice. Thanks for the tip!
  16. twinkiex

    twinkiex Guest

    i think the most relyable bike is the 2 stroke Spooky Tooth. I have put thousands of miles on mine, my Cat Eye says over 600 since December when I finally bought an odometer/speedometer.
    I have no engine problems whatsoever. I just tighten all those little bolts every weekened and carry the oil in a little glass jar and I have no worries.
    I love the custom built bikes I see here but for me I need the relyability of a a Spooky Tooth.
    Last edited by a moderator: Jan 29, 2008
  17. fetor56

    fetor56 Guest

    "oil in a little glass jar"....fuel oil is this?
    What's the setup there please IF it is fuel u tip the oil into the tank at a garage then fill it up with gas then shake the tank?
  18. twinkiex

    twinkiex Guest

    I carry 3 oz of Motol 600 2 stroke oil in a jr baby food jar in the side mesh pocket of my backpack. The jars are strong, air tight and cheap to replace. I buy $1.50 of premium gas, I put in half the gas, add the oil, shake, then add the rest of the gas and shake shake shake! I gave up mixing gas in a gas can months ago.
  19. fetor56

    fetor56 Guest

    I thought of doing that but didn't know how realiable it would be for mixing the fuel properly....i WOULD use it in an emergency for very long trips,but for everyday commuting it seemed unnecessary.
    Handy to know though.

    BTW...Motol is great,use it myself.
  20. twinkiex

    twinkiex Guest

    I ride so much and never know when my tank is low so I have to carry oil. I just do the math at the gas station. If a gallon of permium is 3.19 I pay for exactly half that and the 20:1 ration is 31/2 ozs. I am always within a couple blocks of a gas station so I can let my tank get pretty low.