performance four stoke wanted or a clue as to where to buy

Discussion in 'For Sale' started by mikeag, Jul 19, 2015.

  1. mikeag

    mikeag New Member

    Hi All

    I am having a very hard time finding a Good carb for the 49cc 4G T-Belt four stroke engine. All places I have looked are out of stock. So barring a carb and performance muffler what can I do to add some power to the bike for under $60?


  2. The_Aleman

    The_Aleman Active Member

    AGK sells a performance cam, but it doesn't do much for the price and trouble and AGK has terrible service IMO. I don't recommend doing business with them.

    The GXH50/Huasheng/Titan engine doesn't have a removable cylinder head, so there's really nothing else that can be done to substantially increase performance.

    It would be nice if someone could produce a 1MM longer con rod. That would boost compression to ~9:1 and the engine would make ~3HP with cam, carb, and exhaust.

    Until then, jet your carb properly, adjust valves, run a decent exhaust pipe and you're pretty much maxed. Accept it for what it is, a low-power high-revving engine.
  3. mikeag

    mikeag New Member


    I was going to buy it but they are out of stock!

    Could I have a con rod made at a machine shop? How much would that be roughly? By Con rod do you mean connecting rod?
  4. The_Aleman

    The_Aleman Active Member

    It'll cost more than it's worth, probably. If you really want more performance, think of the old adage: "There's no replacement for displacement".

    Harbor Freight/Predator engines like the 79/99CC will make 3+HP and also have twice the torque of your engine while costing ~$100-150.

    They also have more performance parts available.
  5. KCvale

    KCvale Motorized Bicycle Vendor

    Adjust your HS 142F valves to .04 intake, .06 exhaust and get an NGK 7544 (CR7HIX) Iridium plug, it makes a big difference.
    You can run an NT carb on these engines, and RT I imagine as well, you just need a different intake to account for the angle.
    And a good open exhaust.

    Well, the 79cc is $100but a build costs way more than that.
    A Q-matic transfer case is another $300.

    You also need wider cranks, a throttle & cable, gas tank, back wheel sprocket, chain and tensioner.
    Then you need to make a base, exhaust and design your own throttle linkage.

    Just wrapping up this build today.


    It just needs the throttle kill button hooked up and speedo.
    Joe my shop guy has test rode to and from work a couple times, he says it feels like 50mph but we'll know for sure today.
    Fast sure, but not the least bit friendly to build.
  6. The_Aleman

    The_Aleman Active Member

    When _doesn't_ a build cost more than the engine? :rolleyes7:

    And one isn't forced to use a Q-Matic. There are transmissions for half the cost that bolt up to those motors.
  7. KCvale

    KCvale Motorized Bicycle Vendor

    Got a link? Because this 79cc build has been a nightmare.
  8. The_Aleman

    The_Aleman Active Member

    ProMod jackshaft, can bolt to 79, 99, 212 as well as the Honda GX series


    it's extremely customizeable. I've had one for several years purchased from AGK.


    The clutch can be mounted on engine shaft or mounted on rearward shaft and underdriven like a Q-Matic's. It's a little wider than a Q-Matic, especially with optional aluminum cover.
  9. KCvale

    KCvale Motorized Bicycle Vendor

    That looks like a good solution for cheap custom high HP motorcycles, but wider than a Q?
    Jezz, that thing is already twice as wide as say a 4G, but those are meant for much lower power engines, and on a bicycle with pedals ya know?

    At 1/3 the price of a Q though, a good option for the DIY crowd just looking for a box of parts that play nice together.
    This is so overlooked by so many I think...

    A 'box of Parts' that play nice together even if you don't use them as intended, and usually not all the parts in the box, is the life blood of innovation.

    Piece Meal part buying is fine, but buying most of what need in one box saves a bunch of money just in shipping, and what you don't use today you may need tomorrow.

    That's how I do it anyway ;-}