Huasheng Questions

Discussion in '4-Stroke Engines' started by flashstar, Jul 6, 2010.

  1. flashstar

    flashstar Member

    I recently purchased and installed a 4g kit from bicycle-engines on my 1992 Spectra bicycle. I ran it 40 miles today without any show-stopping issues and changed the oil (it was filled with metal shavings... I'm guessing from break in). Overall, I'm really impressed with the performance of this engine. The only downside is the weight and width of the entire 4G setup. I have a few questions however.

    1. There are two wires coming from the engine that end in a plug. Do these connect with the two wires leading to the kill switch in the throttle grip? If so, does the order matter?

    2. The engine runs really well with minimal vibrations with throttle but the idle is fairly erratic. The engine speed changes by a couple hundred rpm every second at idle. I made sure that the engine is getting a good flow of gas and that the choke was off. Should I make sure that the spark plug is gapped properly (I never checked)? Is it worth setting the A/F ratio?

    3. I can't get the rear sprocket to stay centered after riding the bike for a few miles. It will stay true side to side but not vertically (on the y axis). I was thinking about getting it trued and then applying a couple of drops of JB weld. Is this a good idea? I'm also running a 44 tooth sprocket and it doesn't seem to have any issues with any of the hills in my area. Do you think it's worth going with an even smaller sprocket? (Before break-in the engine's max crusing speed seems to be around 27 mph).

    4. Are half links usable at all to get the drive chain length correct without using a tensioner? I tried before on my 2 stroke but the chain kept popping off the rear sprocket.

    Also, I asked these questions on the other major motor bicycling forum and one of the members there said that metal shavings are never a good thing. I then stopped and listened to the engine idle carefully and heard what sounds like whining bearings (a high pitched metallic noise). Also, I cannot get the engine to run smoothly at idle even though I adjusted the carburetor according to the guide, made sure the plug was gapped properly, and cleaned out the jet on the top of the carburetor. Should I look at getting a replacement engine?


  2. KilroyCD

    KilroyCD Active Member

    Let me address some of your concerns.
    Metal shavings are definitely not a good thing. I haven't had any with my Hua Sheng engine. I suspect there is some internal mayhem going on there.
    Regarding the wires, if I remember correctly the plug hooks up to the kill switch. The order didn't matter when I hooked up mine.
    If you aren't able to keep the sprocket centered, I suspect that the bolts are not tight enough. One good way to eliminate the problem is to get Creative Engineering's sprocket adaptor, provided your rear hub is one of the types he makes the adaptor for.
    Going to a smaller sprocket will certainly help the top end, but will not help you climb hills. Keep in mind that once the engine is broken in it can rev to 8500rpm, and depending on your final drive ratio I would expect higher speeds than the 27mph you are experiencing.
    Half links have not been a problem for me (yet). It may depend on your chain size and drive type. Mine is currently on an EZM Silent Drive unit.
    Regarding the idle, this engine is supposed to idle around 2000rpm. Much below that could result in a rough or uneven idle. Also, I wouldn't rule out a bad float. I had one in my carb. When I removed it, it looked like someone had stepped on it.
    I hope this has been of help to you.
  3. Irish John

    Irish John Guest

    Hi Flashstar,
    I cannot find out what a 1992 Spectra bike looks like but your rear sprocket problem could well be caused by either one of the following:
    1. Your frame is too lightly built to withstand deflection caused by the pull from the chain. A lot of rear axle lugs deflect on the cheap cruiser models I find.
    2. Sprockets & chain rings are seldom perfectly round but it helps if you can spin the wheel fast when centering the sprocket to minimise up and down movement and eliminate sideways wobble. Slowly checking while tightening the sprocket clamps really helps to get the best drive train alignment. I find it helps if I drill out the centre hole of the sprocket to make a larger hole that allows for better alignment on the hub. A clamshell sprocket is the best answer but they don't make them to fit internal multi-geared hubs which seem to come on most cruisers.
    Re the wiring the kill switch I hope the attached picture helps you - you are basically spot on anyway in what you wrote.
    Re the metallic stuff in the first oil change - are you talking metallic dust or metallic shards? The latter is really serious and is indicative of something I have long expected - deliberate quality fade in the manufacturing process. If the latter is true you should try for a replacement under warranty. Metallic dust is standard on the first oil change.
    If you go to a smaller sprocket than a 44T (presumably 36T or maybe 40T) on the rear hub it can cause problems with interference with the rear brake arm if you have a coaster brake. I am interested to know if you have a Mark 2 4G kit or a Mark1 because I found the reduction ratio on the Mark1 really hopeless and if I hadn't given up on it as I did i would probably have ended up with a 40T rear sprocket and that would have made the problem of the torque pulling the freewheel drive sprocket apart even worse because the strain on the drive sprocket would increase. Maybe your sprocket is rigid and not a freewheel. Is it an 11T freewheel drive sprocket or a 10T rigid one?
    Lastly AF mixture often needs adjusting on the HuaSheng and if you find it hard to do ask a mechanic to do it for you. You shouldn't need to do the valve clearances but if you do there is a thread on that on this forum.
    Likewise with the spark plug gap but I doubt it is your problem.
    Hope this is of some help.

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