Huasheng 4-stroke problems

Discussion in '4-Stroke Engines' started by R31 POWER, Apr 7, 2012.

  1. R31 POWER

    R31 POWER New Member

    I've spent hours today reading posts on here trying to find answers for my problem. Motor is on a stand up scooter.
    Motor starts beautiful with choke on. Turn it off it's still sweet. If i give it to much throttle when i take off it will stumble then come good. I put this down to it being a small engine and i can live with that.

    About half throttle it will surge and if i give it more gas it's fine till just before max revs when it surges again. It has stock air filter and exhaust. Full throttle and holding it there it's fine.

    This is the strange part. Every 10 minutes or so it will just bog down hard, even with full speed. It will idle rough and any throttle will make it want to stall. If i suck on the fuel bowl over flow hose and restart it it's fine:confused: Why is this?
    Another 10 mins or so and it will do it again. This can happen at full speed or going really slow.

    Things i've done to fix it.
    - New ngk CR7HSB plug
    - Full carby clean, like 7 times. Main jet is clean and all holes blown with compressed air and fine wire pushed through them
    - Tried 91 octane and 98 octane fuel
    - Breather hole on gas tank lid enlarged.
    - Fuel hose not restricted.
    - All gaskets between carby and head are gasket glued with original gaskets.

    Could it be float level? main jet size? kill switch faulty?


  2. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Remove air filter element. Sometimes oil [from the oil vent tube] will clog breather.

    Also check muffler to make sure nothing has moved inside and restricted the exhaust flow.

    Have fun,
  3. R31 POWER

    R31 POWER New Member

    Checked both and they are clean/ un blocked.

    Progress from today. Pulled carby apart again and really wanted to check the float level. I noticed sometimes it would stick!! So i lightly sanded the pin and up where it goes. Alot smoother now and didn't stick.

    Reset the idle mixture screw to start fresh. Ended up getting to to run really good. Slight bog down every now and then if i give it to much throttle on take off. Another thing is it wont bog down and die like before! I think that float was getting stuck.

    All good things came to an end when it snapped a clutch bolt :p So it's out of action till thats replaced.
  4. The_Aleman

    The_Aleman Active Member

    Have you adjusted the valves on your HS? They are usually off from the factory. Setting them correctly may remove that slight bog you still have. Did wonders for mine.
  5. Max-M

    Max-M Member


    Do you have the specs on the valve adjustment for the Huasheng 142F? I got the factory in China to email me a copy of the owner's manual, but it neglects to mention that adjustment.


  6. The_Aleman

    The_Aleman Active Member

    I set mine at .004-.005" intake, .005-.006" exhaust. Seems to work well. I check them every oil change, like an aircooled VW.

    Edit: check em cold. NOT like an aircooled VW lol
  7. R31 POWER

    R31 POWER New Member

    Cheers Aleman!! I will check that out tomorrow :)
  8. The_Aleman

    The_Aleman Active Member

    I should mention the GXH50 manual says .008" intake, .011" exhaust.
    The stock plug is a "5" heat range, so you may want to set them closer to the Honda specs if you're running the stock plug or equivalent.

    I run a "7" heat range, a cooler plug, so I can get away with tighter settings. It's totally up to you guys what to set em at. Just set em!

    First time I checked mine, they were .012" intake and .024" exhaust! My engine was sluggish and bogged quite a bit, with a nasty dead spot in acceleration.
    That went away with the valve adjustment and I picked up 4MPH on the top end. :grin5:
  9. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    The clearance is in MM.

    I set mine at .003" intake, and .004" exhaust.

    .011 MM = .0043"
    .008 MM = .0031"

    Have fun,
  10. The_Aleman

    The_Aleman Active Member

    Good call Quenton. I guess I was thinking like AGK, they recommend .008" when their performance cam is used.
  11. R31 POWER

    R31 POWER New Member

    Ok I just set them. They were fairly loose! i will take it out for a ride and report back :D
  12. R31 POWER

    R31 POWER New Member

    Just got back from an hour long scoot. The bog is still there but i can just throttle around it. Mid range seams a little more meaty.

    It still surges on anything but full throttle, strange. Not bad but i can feel it. Induction noise has little pops when it does.

    Hows this plug look? This is from about 3/4 throttle and killing the engine straight away so not to idle.

    Attached Files:

  13. R31 POWER

    R31 POWER New Member

    May have found this low throttle problem and surge. Pilot jet has no o ring........ All that fuel leaking past the jet mustn't be good for it hahaha.

    The guy i bought this scooter off said he pulled the carby apart and i guess he never put that o ring back! I will try and get one from the honda dealer tomorrow and report back.
  14. R31 POWER

    R31 POWER New Member

    I made an o ring from some rubber hose just to see and it worked! It's only temp as i think the fuel will melt it and the seal might not be 100%. It now idles nice and i dont need to use the throttle to start it :D
    It also used ALOT less fuel on the same journey i did before. It did'nt surge for about 30 mins. An hour after that it started to so i guess the fuel is eating that hose :p
  15. R31 POWER

    R31 POWER New Member

    Carb jets cleaned one more time just incase, honda pilot jet o-ring and honda air filter fitted. It runs perfect. Adjusting the idle mixture screw actually does something now :p

    It went 38kph according to the gps. Im trying to hunt down different sprockets for more speed at lower revs.
  16. rawly old

    rawly old Member

    Anyone out there know where I can get a diaphram carb adapter for
    an hs 142.? Dax is out of them for a few weeks.:confused:
  17. darwin

    darwin Well-Known Member

    Bicycle engines should have them, when you see the price remember that it includes thye adapter kit and the carb.
    MotorBicycleRacing likes this.
  18. rawly old

    rawly old Member

    Please tell me you don't mean They don't have
    it, and I wouldn't buy squat from them again if they did. I may just
    have to wait until Dax gets more.
  19. darwin

    darwin Well-Known Member

    Rawly ok its a nogo on that site. I've seen those carbs on scooter sites like monster but you need to make sure it will fit. They look exactly like the one dax has but i'm not 100%, get some advice and the prices are reasonable.
  20. rawly old

    rawly old Member

    Thx darwin,
    I'm sure you are right, which is why the adapter. I already have boocoo
    carbs. Anyway, problem solved; I made my own adapter, and it'll work
    just fine.

    "If ya can't buy it; you'll just havta make it yurself.":idea: