4 stroke vs 2 stroke

Discussion in 'General Questions' started by paintvalleymusic, May 25, 2007.

  1. My concern over the smaller engines is the db level...especially the 2 strokes. I really don't want a giant mosquito following me everywhere....which is what some of the smaller engines sound like. Maybe the technology is out there that makes these little engines quiet, but I haven't really seen it. Noise levels are a concern to me, since I'm trying to advance the cause of small engines in my area. If they are loud and annoying, we won't get the average person to buy into the technology. Any pointers out there? Thanks

  2. azbill

    azbill Active Member

    I found the stock exhaust to be pretty quiet
    I heard the engine and gears over exhaust
    even after cutting baffle, It is still hard to hear anything from pipe over the purr and whine of bike
  3. gone_fishin

    gone_fishin Guest

    i constantly ask for opinions...concensus around here is it's pretty much the quietest functional motor vehicle going 8)
  4. RandyL

    RandyL Guest

    I bought a 4-stroke GEBE engine because of their reputation for being quiet. It is fairly quiet but I would prefer it to be quieter because I ride through my neighbor hood at 5:30am and part of my commute is on a greenway trail system (No Motorized Vehicles Allowed). I called GEBE and purchased an add-on muffler that is said to be so quiet it creates problems with pedestrians hearing the bike coming. I'll post again once I have it installed but it sounds like it will probably work well for me.
  5. OldPete

    OldPete Guest

    I am at the same crossroads OP. The choice for me from Golden Eagle is between the Robin EHO 35cc or the Tanaka 32cc. In his ad copy, Dennis states the Tanaka 32 is 2dBA quieter than the 35cc Robin when both are at 27~28mph. I want to order this Wendsday...*sigh*
    I guess I'll email GEBE and inquior...about the aux muffle too. I want to ride the flood control channels here w/o scaring the sea birds or waterfowl or alerting "the man".
  6. Fearing "the man" myself.....which is why I thought of putting a small 4 stroke in a trailer (hidden) and having the trailer push me. Out of sight, out of mind.....plus you can unhook it if you want to, plus use it to haul your lunch and briefcase, etc. Some of these small 4 stroke Honda's are $200. Of course, they are too big to mount on a bicycle.....but a trailer or tagalong would work great. What does everyone think?
  7. OldPete

    OldPete Guest

    No one needs/wants a trailer pushing them, that's why many trailers have a surge brake master cyclinder built into their hitch. It only applies the trailer brakes when the unit wants to get ahead of the towing vehical.

    I MUST be legal with my motored bike because it will be used for real transportation. Here in CA the operator must be > 16yo, I'm 60. Operator must have a M-2 CDL cert, that will be done. Motor must be under 50cc and < 2hp. That can be done with the Tanaka 33 or the Robin 35. Exhaust MUST NOT be modified. I hate noise, I had enough riding real motorcycles for many years. New micro-motors sold here MUST meet the C.A.R.B. II cert, both the above comply.
    Our rivers here are paved with concrete, we call them flood control channels. The bank tops offer wide bike paths that are nearly deserted on week days :cool: :grin: . THAT is why I need extra quiet.

    Read your State and local laws carefully. Make copies to carry with you. Cal DMV 406 A&B and 4020 are already in my printer tray. :smile: [/b]
  8. thatsdax

    thatsdax Guest

    2 VS 4

    Both 2 and 4 strokes are very quite for sure. Very... You talk over the motors at idle with ease. Under load, the 4 stoke transmission becomes a loud noise maker for sure !! That is one of the biggest draw backs to my 4 stroke. After the noise comes the size and weight. so..If you can get over the loud trannie noise, the large size and weight..then..Go with a 4 stroke. If you want power, light weight, and more quite, then the 2 stroke is the way to go for now..Thanks..Enjoy the ride..
  9. Which two engines are you comparing?

    I still think a little pusher of some type is worth a try. Doesn't have to be complicated and could help carry loads. Yes, for sheer maneuverability's sake, go for the mounted engine, but where hauling groceries or anything of size is concerned......this pusher might work for us country folk.

    Keep the tips coming.........pro and con.

  10. DougC

    DougC Guest

    I have a 4-cycle 35cc Robin-Subaru engine, and the noise is more than I care for as well. The engine is a small garden-equipment type, and to keep the overall package compact there's not much room for a muffler on it. The exhaust now sticks straight out the right side, and when I go by a building or vehicle I can hear the engine really well.

    I had begun making a giant muffler for it--but When I get it fitted to the destination bike, I may just try clamping a short bent piece of tubing onto the exhaust pipe, aiming upwards at the sky and tilted back at an angle (20 deg from vertical or so). Most of the exhaust noise that's annoying is the higher-frequencies, and those only radiate in one direction.
  11. gmanning66

    gmanning66 Guest

    anyone tried the "quiet" Mitsubishi engine?

    I have the same problems/concerns as you guys, noise ! I keep reading how quiet the 43cc Mitsu engine is. Anyone try/buy it and can comment? thx
  12. Cowled_Wolfe

    Cowled_Wolfe Guest

    I've got the GEBE R/S 35 as well. Right now, I'm contemplating various ways to use up a propane cylinder without wasting it, so that I can make a DIY muffler.

    If it works, I'll be posting pics / a how-to... Come to think of it, I've got a dozen and one pic / how-to articles that I need to do. (My GEBE is rather heavily modified.)

  13. tfhudson

    tfhudson Guest

    My 2-cycle chinese happytime kit from kings was really quiet before I modified the muffler. It was easily on par with most motor scooters.

    If I ever needed it to be any quieter, I would've just temporarily disengaged the clutch and let it idle, or even killed the engine, till I passed through the sensitive area. But that was really never needed with the muffler as shipped.
  14. Ca Law concerning displacement

    Ol Pete, CA law does NOT call for under 50cc's, it calls for:

    less then 30mph on level ground
    Capable of Human Propulsion ie. Pedals
    single cylinder
    no transmission more than a 2-speed fully automatic
    Less than 2 Gross Brake HP

    This is why Whizzer is a legal Moped

    we need to be sure this is well understood.

  15. JosephGarcia

    JosephGarcia Guest

    riding those channels are FUN! I have the san gabriel river here and i wish i still have my motorized bike, cant go into those with a harley. haha
  16. Alaskavan

    Alaskavan Guest

    Gmanning66, I have a Mitsu TLE 43 on my Trek. It made a little more noise than I cared for, so I installed a pipe to redirect the sound down and behind me. It's pretty quiet.
    P.S. Who are you?
  17. OldPete

    OldPete Guest


    Many modern 2 strokes that are 40~50cc produce > 2 gross brake horsepower. IIRC the Tanaka 40 is speced at 2.2hp.
  18. Douglas65

    Douglas65 Guest

    In my experience, all engines both 2 and 4 stroke are extremely loud. It is the mufflers that make them quiet, and it is the type and style and construction of those mufflers that should be compared to achieve a quiet running bike.

    I agree that we need quiet bikes. Almost so quiet to be dangerous on the sidewalk, and any engine can be make quiet if muffled correctly.

    Another idea, some styles of pipe/mufflers, especially for 2 strokes can improve HP, but I would prefer a 4 stroke with a large enough exhaust pipe and muffler to keep it quiet and not effect (lower) engine power. Easy to do, it will probably take up a little more room though.

    Hopefully I am not just stating the obvious, but I think that if we really want quiet, we need to focus on the muffler, not the engine.
  19. Douglas65

    Douglas65 Guest

    I also wanted to add to the above idea.

    When listening to engines, the engines that produce the most complaints are the higher pitched 2 cycle engines. This comes from personal experience and many years flying remote controlled airplanes. The high pitched noise (like a mosquito or baby crying) tends to be the most annoying while a lower pitched engine sound (like a 4 cycle lawn mower engine) tends to blend in with the background if not too loud. Think about it, lawn mowers are running all the time in the summer and I almost never even notice them, but if someone blocks away starts a chainsaw, I notice it.

    So it isn't just the decibel level, but the pitch that we need to be concered about in order to not attract negative attention.
  20. Mountainman

    Mountainman Active Member

    Yes, I have seen a trailer mounted small engine a few years back here in San Diego.. I talked with the owner many times.. He seemed to be pretty darn happy with it -- said that his cruising speed was between 20 to 25 mph. Had a larger Briggs and Stration type of engine.. I think that a smaller engine (could be hidden fairly well) Have a blessed day, Mountainman