4-stroke engines quieter?

Discussion in '4-Stroke Engines' started by How2, Jun 18, 2008.

  1. How2

    How2 New Member

    hello all... noob here.

    i've been told that 4-stroke engines are quieter than 2-stroke, but that they require more maintenance (ie. oil changes, etc)

    In your opinion, which is the quietest motor and why? Are mufflers effective and what is your experience with them, if you choose to answer with mufflers as a component in your answer.


  2. HoughMade

    HoughMade Guest

    4 strokes are quieter than 2 strokes- no doubt. Mufflers help, but all of these engines require some sort of back pressure to run correctly so running without one is not a good idea. I suppose a guy could run a straight pipe, but it would just be loud and performance would not really be better.

    There is not more maintenance with 4 strokes, but the type of maintenance will be different. No oil changes with 2 strokes, but plenty of other things to mess with...of course there is the mixing oil in the gas every time you fuel up.
  3. How2

    How2 New Member

    Thanks for the response Houghmade.

    Initially, the oil mixing on the 2-stroke seemed like a bother to me. But everything i've been reading seems to indicate that overall, they are easier to maintain.

    I currently have an electric bike, but i've run cost comparisons and find that a gas motorized bike is a better way to go. Battery costs are killing me!!! Even if gas goes to $30/gallon, it will still cost less to run a gas motor bicycle than an electric bike due to battery prices.

    Sooo... I am going to motorize my other mountain bike and use it for longer distance trips, and keep the electric for the "close to home" trips.

    I have much research to do to figure out what motor kit is best for me.

    Thanks again!
  4. Mountainman

    Mountainman Active Member

    From the old guy --- 2-stroke - fast on the top end - wind them up - louder for sure - less torque on bottom end - very fast on top end - high revs ------------- 4-stroke - quiet - more torque bottom end - no mixing of oil with gas - more moving parts - valves, push rods, timing chain ect.
    Happy Riding from - Mountainman
  5. HoughMade

    HoughMade Guest

    It really depends on what kind of 2 stroke you are talking about.

    These cheap chinese 2 strokes- fun and many people enjoy them, but they are maintenance intensive. You are always messing with some sort of adjustment and tweaking something.

    A higher quality 2 stroke, like for instance, the Tanakas will likely be less maintenance. There are more moving parts in a 4 stroke- but look at what we are talking about- in the case of my Honda, after the first 10 hours (oil change and adjust valves) maintenance is very infrequent- beyond just keeping an eye on things. In any event- with quality 4 strokes or 2 strokes, we aren't talking about weekly adjustments, or even monthly adjustments (engine wise at least, bike likely will need adjustments) once everything is running right, there is little to worry about either way....but the 2 stroke will always be louder.
  6. eljefino

    eljefino Member

    4-strokes emit a lower frequency noise that blends better with one's surroundings. People go deaf on lower frequencies first so 2-strokes seem louder yet.

    Lacking a gas gauge, it is often difficult to know how much fuel one has remaining when they buy fuel... which makes mixing 2-stroke oil to the right ratio a challenge when one is off touring. If they exclusively use a premixed can from home this isn't such an issue.

    If both were the same price, reliability, and power output I'd go for a 4-stroke instantly!
  7. ZnsaneRyder

    ZnsaneRyder Member

    I notice that 2 strokes have to be adjusted a lot. Another thing is they bog a lot until they are hot. For that reason I want to go with a 4 stroke. I'm about to get a 3.5HP Horizontal-Shaft Briggs&Straton engine for a bike trailer. I've never had much trouble keeping a lawnmower running good, so that's why I decided this engine, it's similar, but has the shaft like a go-kart engine. The engine is from an edger, and has a small pulley already on it. I'm making a clutch using an idler pulley, and a cloth woven riding mower belt so it can slip some when clutching. The axle has a 6-inch pulley and small 10 inch tires, so hopefully my ratio is low enough.

    I'm hoping a cheap muffer from a tractor or car can quiet the engine down a bit though, but it's still much quieter than a weedwacker or chainsaw engine.
    Last edited: Jun 19, 2008
  8. I like the 4 stroke because it's quieter than my 2 stroke. It also runs cleaner so you can muffle it better. I tend to over oil my 2 stroke Happy Time so that black oil drips from the exhaust so I opened it up making it louder because I got a serious clog before I did.
    On the 4 stroke since the oil is in a bath the emissions is alot cleaner so you can get away with an exhaust that's quieter with no real worries that it will clog up.
    I also like that you simply pull up to the gas pumps to get your gas without worrying about mixing. That to me rules.
  9. ZnsaneRyder

    ZnsaneRyder Member

    I agree. I'd hate to mix oil if I had to fuel away from home.

    And for a 4-stroke, oil changes are no problem, being they take less than a quart of oil!
  10. kymics

    kymics New Member

    I thought I read somewhere that you're not supposed to fit external mufflers to 4-stroke engines like the EHO35 because it can hurt the engine.

    But I do notice that when it comes to frame-mounts, the HuaShang and Honda 50cc 4-strokes have a similar muffler used on the HT kits.

    The built-in muffler on the rack-mount kits seems pretty small, so am I right to assume that a frame-mount Honda would be quieter than a rack-mount Robin Subaru?
  11. HoughMade

    HoughMade Guest

    No, I don't think a frame mount is any quieter due to the muffler. The external size of the muffler does not mean much. The amount of restriction in the muffler is what affects the sound. I ran my Honda with the stock muffler before I mounted it on the bike and if anything, it is a big louder with the larger muffler attached.
  12. darwin

    darwin Well-Known Member

    My honda gx50 is quiet as a whisper at idle and at 3/4 its still quiet. As to a 2 stroke do you ever want to throw rocks at the landscape guys doing lawns cuzz they make so much noise? That should answer your question.
  13. Zev0

    Zev0 Member

    I have 3 engines. 2 2-strokes and the RS EHO35. I prefer my tanaka 33cc 2stroke over the other 2. Louder? Yes. And the out and about problem of mixing oil and gas is taken care of by just carrying 1 or 2 bottles of pre-volumed oil to put in gas tank when refueling. I can run the 2 stroke ALL day long. Can't do that with the 4 stroke. Neither can the 4 stroke be run at full throttle for long periods of time. I guess it's just really a matter of what floats your boat. Mine is floated by the Tanaka 2 Stroke.
  14. duivendyk

    duivendyk Guest

    2 strokes have twice as many explosions than 4 strokes for the same rpm,so the exhaust note is more high pitched that's why they sound "louder",more "piercing" is prob. the right way to describe it.They are also sensitive to the exhaust system,esp. when high-end performence is concerned.With
    proper intake &exhaust tuning they are capable of astonishly high performance.All records in motorcycle racing were held by 2 strokes.Ignition is also critical, the plug fires at twice the rate.It's like comparing a finely tuned but temperamental race horse to a more reliable but plodding Clydesdale.I have allways ridden 2 stroke cycles, ( DKW,Suzuki Yamaha Kawasaki)because of that nice combination of low weight&high power,only the Kawsaki Ninjas are in that class.
    A 4 stroke engine is not hurt by the exhaust system but a clogged one (unlikely) can cause overheating which can burn your exhaust valve.But if you have none at all you may warp the E valve upon shutdown due to rapid cooling.Low quality 2 strokes like the HT engines are not worth messing with in my opinion,unless you are a glutton for punishment but the Japanese ones Tanaka,Mitsu. are nice light simple and reliable engines.The Mitsubishi TLE 43 engine has a clever scavenging system that reduces emissions significantly while improving gas consumption
  15. astring

    astring Member

    by full throttle do you mean above 20mph:grin:?

    what happens when you try to run the eho35 all day?what does it do?
  16. Zev0

    Zev0 Member

    I mean FULL throttle. Try and run it full throttle for quite awhile. See what happens. As for running it all day, can you say dead horse.
  17. HoughMade

    HoughMade Guest

    My Honda 4 stroke carries me close to 40 mph at full throttle....Do that for too long and it'll blow, but I can run "all day" at 25-30.
  18. duivendyk

    duivendyk Guest

    Most engines are simply not designed to be run at full throttle or very high rpm for extended periods.The inertional forces go up with the speed squared.This produces high stresses and much accelerated wear on the crankshaft and con. rod bearings.Cooling may also become inadequate,resulting in piston failure.There the forced-air cooled engines have a significant advantage.Lean mictures are a death sentence,extra alcohol with it high heat of evaporation helps cooling things down inside.Synthetic oils that don't break down at elevated temp. are essential.Because of the limited power availability, it's easy to overstress these small displacement engines.Two strokes tend to be more robust because of their inherent design simplicity (as long as they don't overheat).Lower quality engines should be treated gently, that means, look for larger displacement one and ride conservately.It will make them last a lot longer.
  19. I can change my Titan engine 4 times from one quart of oil. So with that I got Racing Mobile One Synthetic 10-40 at $9.50 a quart.
    I like that it's 10-40.
    This gives me peace of mind that I can make a small investment for reliability.
    It's overkill but so what.
  20. Mountainman

    Mountainman Active Member

    Forgot to mention that if we are truly trying to save in regards to gas cost -- I believe that 4-strokes are MORE GAS EFFICIENT... Happy Riding from Mountainman