Expansion Pipe question for 2 stroke 48cc.

Discussion in '2-Stroke Engines' started by geebt48cc, Mar 19, 2010.

  1. geebt48cc

    geebt48cc Member

    So, I wonder if an expansion pipe would really give my 48cc grubee a little more torque up hills? Up small grades, I can average around 20mph, but not the best on good sized hills. Any ideas.................:cool2:

  2. professor

    professor Active Member

    Everything I read here indicates a definite improvement on overall power. Go for it, but use one that has a good silencer on the end of it.
  3. geebt48cc

    geebt48cc Member

    TY, where would you suggest that would work well, but not to loud?
  4. professor

    professor Active Member

    One of the other guys will have to chime in on which one. SBP ? (one of the advertisers on the lower left)
  5. retromike3

    retromike3 Member

    I got one and I like it :grin5:

    I have a S.B.P. pipe and it makes a huge difference in the power and usefulness of my M.B. I can get around the suburbs quite well here with my little bike. Its a 65/80cc Zoom cycle and with this pipe the horsepower effectively doubled.

    I do have problems with the motor though. It seems to want to have any part I bolt to the frame rattle off and I am constantly retorcking the head bolts. but it seems to work pretty well.

    Mike Frye
  6. arkives1

    arkives1 Member

    Expansion pipe question for 2 stroke 48cc

    I'm running two of the same engines Mike, and I know there's a lot of vibration but I think that's true with any of the two strokes. Rubber padding on the engine mounts helped a little and I use blue locktite and lock washers on everything sometimes double nutting to be sure. Nylock nuts seem to work well too but I wonder about the heat on the engine.
    Now if I could only find a way to seriously reduce the vibration to ME. Bone shakers is what I'd call em.
  7. Apachekid

    Apachekid Member

    Expansion chamber great addition...you will notice the difference inmmediately in low and midrange power...But, like the Professor says..DO NOT FORGET THE SILENCER..SBP has got a good kit! Ive taken mine off temporarily to give my neighborhood a break.....until I figure out a better muffler!
  8. retromike3

    retromike3 Member

    how loud is loud?

    Grated these little engines make a bit of noise but I have not noticed that much of an increase in the db rate with the expansion pipe. I do remember when my old exhaust pipe rattled off about three blocks from home and I got quite a few complaints, man was that loud. For me personally it does not seem as loud because the end of the pipe is farther away from me than the stock pipe and I kind of like that noise.:cool:

    Mike Frye
  9. geebt48cc

    geebt48cc Member

    Mike, yes I understand....................So, would you go with the expansion chamber pipe from (SBP)?
  10. motorpsycho

    motorpsycho Active Member

    I'm using the spooky tooth expansion chamber because of clearance issues on my 20 " frame. i did notice quite a difference in power, but more on the top end than the bottom end. i modified the inside and outside of my stock muffler and used it on the end of the expansion chamber. with no muffler / baffle the s.t. expanson chamber is VERY LOUD and really doesn't make much difference by itself. but, with a high flow muffler /baffle on the end, it make a huge difference. I actually took my stock muffler apart, gutted it, cut a 45 degree slash in the end and put it back together. i drilled holes in the baffle plate that's inside of it one at a time. i tried the muffler after i drilled each hole and when i got to the point where there was no performance increase and a noise increase, i welded one hole shut. as it is, i have 3 holes drilled in the baffle plate on the side furthest away from the exhaust outlet. the exhaist flows through those holes, but it still has to go through the baffle before it exits the pipe. it's almost as quiet as it was with the stock muffler & pipe, but it has a ton more power. it has a nice healthy / raspy sound but it isn't annoying.
  11. Apachekid

    Apachekid Member

    Say psycho, Ive got the spooky x chamber also. Im running it right off the block. It is very LOUD even with cheap lawnmower muffler. I managed to weld a 3/4" thread fitting onto the stinger but Im still looking for quieter muffler. Havent got any clearance for xchamber anywhere else unless I really do some mods...That 66 Triumph is cherry! I want it, give me, give me....Seriously, I had a crappy old Ducati back in the sixties and I always wanted a Triumph. I just love the sound of a Triumph....Cheers, Apache
  12. geebt48cc

    geebt48cc Member

    Wild man!!!!!!!!!!!!~ Go with a Concours ZG1000.........................................

    Thee **** with this ("""") stuff.........................
  13. motorpsycho

    motorpsycho Active Member

    i too tried a lawnmower muffler at first and all it seemed to do was collect oil and drip it all over the place.
    i also was going to try to use a baffle from an 80c.c. honda dirt bike, but it was way too big to fit on my bike.
    That's another solution if you have the room. try to find an older baffle from like an 80 c.c. or 125 c.c. 2 stroke dirt bike. look for an older one (like from the mid-late 70's) because they are smaller than the newer ones are. you can find them failry cheap on e-bay from time to time. the one i have is from an early 90's honda cr 80, but it's way too big for my bike and it's rectangular rather than tubular. i have a 20" frame and my bike is a lowrider, so don't have a lot of ground clearance or frame clearance. if you want to give it a shot, i will sell it to you cheap or trade you something for it if you want...i have no use for it.
    here's what my modified stock muffler looks like on the s.t. chamber.

    I hide the end of the muffler that has the small outlet hole in it, up inside the muffler tube, so you can't see it. with the slash cut on the end, it looks like it's just an open pipe.


    If your stock muffler is not welded together, you can take it apart and modify it like i did. if it isn;t welded together, there will be 3 screws on the outside holding the whole thing together. once you get the screws out, you will have to put a bar or something in the end that comes from the engine (you will have to cut the pipe off for it to fit on the expansion chamber anyway) and pound on the bar to knock the guts out. you will have to put the bar against the peice (see pic below) and pound it, but pound it carefully. it is a very tight fit, but it will come apart. you will probably find that there is a peice inside the stock muffler that looks like this:
    take this peice out and leave it out. it's supposed to be a cateletic converter of sorts for emissions, but in reality all it does is block the flow of exhaust collect oil and clog up the muffler over time.
    if you want to try and do this, let me know..i can walk you through it more of you want. if you look close at the pic. you can see where my bar was at when i was pounding the muffler guts out of it.
    Last edited: Mar 20, 2010
  14. Apachekid

    Apachekid Member

    My stock muffler is welded together..Im going to run it for a while until I find something to stick on end of my s.t. xchamber...You're really getting too complicated for me there, psycho, but you exhaust turned out great and it even looks quiet! Ive got a couple of ideas on how to get my pipe back on. I'll post a pix when I get er done......Cheers!
  15. 210061741

    210061741 Guest

    Ok ok ill let you guys in on a secret.

    If you use the proper STINGER and set it right things will quiet dow.

    I recomend around a 3/4 diameter pipe 6 to 7 inches long.

    you can adjust it by cutting little pcs off the end if you need to.

    Now if you take such a stinger and insert it into the pipe so that the end inside the chamber is past the mean point of reflection of the baffel cone.

    It will be quieter than a chamber with a glass packed silencer.

    If you add a silencer to it .... even more quiet.

    So get some pipe and stick it 2 to 3 inches inside the chamber and give it a whirl.

    It works
  16. biketec

    biketec Member

    Back in the day I used to use steel wool and beer cans in my stinger on my old VDub in CA. and when I felt the need to be harassed (or the harasser) or I was in the desert I would just pull it out. It really does work nice, or you could rig up a side pipe with the quick straight on the header? just some old tricks handed down to me along the way.
  17. motorpsycho

    motorpsycho Active Member

    i am not concerned about the noise level to be honest.
    but an open expansion chamber is actually too loud...annoying loud.
    right now, my bike sounds like an 80 c.c. 2 stroke dirt bike.
    it has the pop, and ratt-a-tatt-tatt sound which sounds good to me.
  18. 210061741

    210061741 Guest

    What im trying to say is if you put the stinger up in the chamber you can run it open.

    It will still sound nice the way you want it too.

    But it will be no where near as loud.
  19. motorpsycho

    motorpsycho Active Member

    yeah i understand that, and i know what you mean.
    But I personally, don't care too much about the noise.
  20. gothicguy64

    gothicguy64 Member

    just thought i say my 20 cents worth

    im riding a shaft driven real wheel inrtral gear 3 spd 26 inch
    with factory 44 tooth rear
    but motor is a RSE hp1 upgraded to 50 hp2
    billet head
    billet clutch cover/ inlet
    ehaust was up dated to poo poo long street pipe
    my low an mid is awesum from a cheep exhaust
    i top at 65 kmh ummm 40 mph
    im goin to get my exhaust upgrade from pirate cycles
    just thought i let there are diff exhaust motor setups out there
    motor prob close to 1800 watts from 50 cc