HELP! 4 Stroke Huasheng engine throws oil out of carburetor

With all that messing around, you would experience far more reliability using a centre mount 2-stroke bicycle engine.

yea, they're far easier to work with and parts are cheaper, im just already too deep into this damn thing to just trash it.. i at least wanna get it running and then figure out what to do with it.. its irritating to say the least, the problem cant be that big.. since it wants to start, just something seems to be holding it back

The trend is going from problematic 2 strokes that require a lot of maintenance to a durable 4-stroke.

We have sold way over a thousand of the HS 142 motors and can count the warranty issues on one hand [less than 5 in 5 years]. It is normally trouble free except for 2 issues.

First and foremost the motor doesn't know when to stop revving [this is also true of the Honda GXH50].
And secondly, today's gasoline is very damaging.

Problem number one usually results in the rod snapping loose and it is over. This problem was caused by several companies offering kits with "crazy" ratios, like 25 X 1. This allowed the motors to rev beyond 9,500 RPMs when the red-line is 7800. Solution was to stop selling stupid ratios.

Problem number two, however continues to haunt all of us. It isn't just a problem with the 50 CC motors, but all small motors. While an in-line filter is good, it won't stop the residue left after the gas evaporates. My solution has been to add Gummout carburetor cleaner to about every 5th or 6th tank of gas. This seems to stop all my carburetor issues on all my EZM bikes, HF equipped bikes, and my vast Whizzer collection [over 25]. If I plan to store one and not use for a while I use STA-BIL, as I found draining the gas still allowed the residue to still form inside the carburetor. In fact I found it works better to leave some gas in the system and allow the STA-BIL to do its job.


Check to see if the flywheel key has sheared, then check valve adjustment. I don't remember the exact valve setting, but I think it is posted somewhere on this site.

Have fun,

obrauthigam said:

, im just already too deep into this damn thing to just trash it.. i at least wanna get it running and then figure out what to do with it.. its irritating to say the least, the problem cant be that big.. since it wants to start, just something seems to be holding it back

Click to expand...

That almost sounds like a metaphor for marriage; given that so much anecdotal evidence abounds.

Thank you, I'll check them out and keep updating

Same could be said about college...
I don't really know how to describe the problems with the engine since I don't really know what the hell I'm doing. But I guess it's time to take it apart and figure it out

The magneto or stator, as far as I know is covered with epoxy and non-removable on the hs engines. If you were able to remove it and put it back on the wrong way, this could cause starting issues. You need 4 things in order to start. Air, fuel, compression and spark. Any starting issue has to be related to too much or not enough of one of those 4 things. Common causes of issues are vapor lock (gas tank isn't vented properly), bad piston rings causing loss of compression, an air leak, a wet/dirty spark plug or a plug that is not properly gapped, too much gas flooding the engine, or your ignition isn't finding a good path to ground or your killswitch is malfunctioning. With the exception of the piston rings, check all those things and if you haven't found the problem, then either your magneto has failed or your piston rings are shot, which I doubt. It's likely to be one of the things I mentioned.

I'd second the motion to check for a sheared key between the flywheel and engine shaft. That happened on my first Huasheng and it caused very rough running like you have. It throws the ignition timing off. You will first have to take the pull start and flywheel cover off using an 8mm socket on the 3 nuts holding them. I forget what size nut holds the flywheel on. Be careful not to lose the 3 little spacers and nuts. Good luck.

Here is the information I received with my Huasheng 142F engine in Dec 2014. I used a food syringe to empty the 8.6 or 8.8 ounces of oil from crankcase. I then used the same syringe to put the new synthetic 10w-30 oil back in the crankcase! I created my own oil changing kit. It does not show the small extension tube I used on the syringe to get to the bottom of the crankcase.

Jimmy H.

I use the same syringe with a little gas line on the end to empty and fill as well.
No mess.
To fill I go until hits the threads.
10 minutes tops to change oil.

If you are getting spark (pull out plug and ground to head) and pull.
You need the ground or it won't spark.

No spark and it's mag or CDI, spark it could just be timing hence the posts above about the key.

If and when you change plugs this is the ticket for 49cc HS 142's.
NGK 7544 (CR7HIX) Iridium.

It's a tad longer than stock for a bit more compression and comes pre-gapped with a big one.
It makes one heck of nice spark and should last the life of your engine.
All my builds get Iridium's.