Huasheng 49cc 4 stroke won't stay running

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Donnyten

New Member
Jun 21, 2015
28
2
3
Durham
Hello people. I did a fair bit of searching before posting this and got similar results but wanted to customize my problem more. I had someone install a huasheng 4 stroke kit onto one of my bikes and the bicycle will not stay running . I have tried adjusting the idle screw but it didn't make a difference. It's still a practically brand new kit with only 20 minutes of use ( testing) the motor has oil and there is gas in the tank. Is there something else I should check for? Bear in mind that I have no knowledge of mechanics or troubleshooting so please take it light in explaining things and please define any terms you use and how I would access these parts.


Basically, the guy who built it didn't test it out. And he lives 3 hours from me.
I'd rather learn how to diagnose and do the repairs myself as to not travel back-and-forth for simple things. So I pull the string on the motor to get it started, and then the guy said that once started, I turn the gray switch to keep it running. I do this, and it idles for a little while then completely shuts off



Thanks
 
Last edited:
GoreWound

GoreWound

New Member
Dec 1, 2014
480
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0
Canada
that grey switch is called the choke what it does is close off the intake so less air is getting into the engine. this allows for easier startyig due to the increase in the fuel present in the engine.

you will want to let it run for a few secconds to a minute before you return the choke to open. (on one of these motors the lever pointing towards the driveshaft side
is in the open position, when it is pointing towards the pull starter
it is in the closed position. closed = choke on, open = choke off) this will allow it to warm up so when you open the choke again the leaner fuel-air mix is still able to be burnt properly as the motor is hot on the inside.

as per the idle screw, my engine at least can be set to run at a drastically lower idle than it will start at, assuming I run it untill it is warm then adjust the idle down. for ease of use I have my idle set slightly high because if it is as low as I can make it; it becomes nearly impossible to start once it cools back down. you may be having a similar issue. when starting it try to give a little bit of throttle (be careful about the bike taking off when it does start though) once you get it started you will want to adjust the idle higher to keep it running.

to check the oil level make sure the bike is not rolling anywhere and the engine is level and cold (has not been run within the past several hours) then remove the plastic oil cap. the oil level should be at the top of the fill tube, sitting in the threads under the oil cap.
check the colour and consistency of the oil, it should be golden yellow and cling to your fingers. it should also have no grit in it. if the oil is brown, gritty, or has lost it's viscosity it is time to change your oil. also if it smells like burnt plastic time for a change.
the oil used for these engines is 10W-30 the maunal suggets using a high detergent oil. there is a metal bolt on the same side as the plastic oil cap but below it, this is the oil drain plug. to change your oil place something underneath the drain plug to catch your oil and remove the drain plug (you may also want to remove the plastic oil cap as well to allow air into the oil pan so it drains faster) it can take a long time for all of the oil do finish dripping out of the engine, but once it does you can replace the drain plug and refill from the fill hole, again making sure to fill the oil pan untill the oil is level with the top of the fill hole.

if you can get a copy of the instruction manual from the guy who put the motor on your bike you may find it useful as a reference guide. failing that the HS-142f engine is a clone of the Honda GX-50 or GXH-50 engine so most if not all doccumentation for the honda engine will be true for your huasheng.​
 
knightscape

knightscape

Member
Jul 29, 2013
340
1
16
Maine
When you say it idles "a little while" how long are we talking?

When mine was new it liked to be given a little extra gas when first started, just a touch above the normal idle point. So I'd fire it up with one hand on the throttle. Once it catches, flip the choke and then after it warms up just a little bit, maybe like 10 seconds I could let go of the throttle and it would idle normally. Now that it's broken in, I can let go of the throttle as soon as it fires, and it idles beautifully. So maybe your motor is just a little tight being new.

And here's a silly one: You are flipping the fuel switch before starting right? If you have the usual kit peanut tank bolted onto your top tube, there should be a switch right where the fuel line comes out of the tank.
 
D

Donnyten

New Member
Jun 21, 2015
28
2
3
Durham
GoreWound said:
that grey switch is called the choke what it does is close off the intake so less air is getting into the engine. this allows for easier startyig due to the increase in the fuel present in the engine.

you will want to let it run for a few secconds to a minute before you return the choke to open. (on one of these motors the lever pointing towards the driveshaft side
is in the open position, when it is pointing towards the pull starter
it is in the closed position. closed = choke on, open = choke off) this will allow it to warm up so when you open the choke again the leaner fuel-air mix is still able to be burnt properly as the motor is hot on the inside.

as per the idle screw, my engine at least can be set to run at a drastically lower idle than it will start at, assuming I run it untill it is warm then adjust the idle down. for ease of use I have my idle set slightly high because if it is as low as I can make it; it becomes nearly impossible to start once it cools back down. you may be having a similar issue. when starting it try to give a little bit of throttle (be careful about the bike taking off when it does start though) once you get it started you will want to adjust the idle higher to keep it running.

to check the oil level make sure the bike is not rolling anywhere and the engine is level and cold (has not been run within the past several hours) then remove the plastic oil cap. the oil level should be at the top of the fill tube, sitting in the threads under the oil cap.
check the colour and consistency of the oil, it should be golden yellow and cling to your fingers. it should also have no grit in it. if the oil is brown, gritty, or has lost it's viscosity it is time to change your oil. also if it smells like burnt plastic time for a change.
the oil used for these engines is 10W-30 the maunal suggets using a high detergent oil. there is a metal bolt on the same side as the plastic oil cap but below it, this is the oil drain plug. to change your oil place something underneath the drain plug to catch your oil and remove the drain plug (you may also want to remove the plastic oil cap as well to allow air into the oil pan so it drains faster) it can take a long time for all of the oil do finish dripping out of the engine, but once it does you can replace the drain plug and refill from the fill hole, again making sure to fill the oil pan untill the oil is level with the top of the fill hole.

if you can get a copy of the instruction manual from the guy who put the motor on your bike you may find it useful as a reference guide. failing that the HS-142f engine is a clone of the Honda GX-50 or GXH-50 engine so most if not all doccumentation for the honda engine will be true for your huasheng.​
Click to expand...



Thanks so much for that post bro. And unfortunately the guy said he did not have the manual​
 
D

Donnyten

New Member
Jun 21, 2015
28
2
3
Durham
knightscape said:
When you say it idles "a little while" how long are we talking?

When mine was new it liked to be given a little extra gas when first started, just a touch above the normal idle point. So I'd fire it up with one hand on the throttle. Once it catches, flip the choke and then after it warms up just a little bit, maybe like 10 seconds I could let go of the throttle and it would idle normally. Now that it's broken in, I can let go of the throttle as soon as it fires, and it idles beautifully. So maybe your motor is just a little tight being new.

And here's a silly one: You are flipping the fuel switch before starting right? If you have the usual kit peanut tank bolted onto your top tube, there should be a switch right where the fuel line comes out of the tank.
Click to expand...
What I mean is, it will Idle uncomfortably shaky for a few seconds and then completely shut off unless I am giving it a bit of gas using the throttle
. I will heed your advice though. I greatly appreciate your response
 
GoreWound

GoreWound

New Member
Dec 1, 2014
480
2
0
Canada
with any luck you will just get the hang of starting it when it will reach it's broken in stage and stop being so difficult.

I just finaly broke down and cut the top half of that lever off for clearance with the frame and started the bike with actually full choke for the first time.
two pulls, no throttle.
rode it around a bit got it warm, switched it off and tried to start it again, took like five or six pulls.

sometimes the beast is in a sour mood. just be kind to your steed and hopefully it will be kind back.

good luck.
 
D

Donnyten

New Member
Jun 21, 2015
28
2
3
Durham
Thank you for the response. What are some common tools I should invest in if I need to take anything loose? screwdriver, check
 
GoreWound

GoreWound

New Member
Dec 1, 2014
480
2
0
Canada
a good wrench or socket set is a must.
a couple of pairs of pliers would come in handy.
I also have a four pound deadblow hammer that I find useful, but that might not be a good thing...
a heavy duty pair of gloves, not just work gloves. I have a pair of insulated leather snowmobile gloves that have come in handy for touching hot parts several times, I also use them as my winter riding gloves.
I would also advise having some spare parts at the ready rather than waiting for something cheap to break before getting one. things like spark plugs, master links, maybe a whole spare chain or spark plug boot. a spare bit of fuel line is a good idea too.
 
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Donnyten

New Member
Jun 21, 2015
28
2
3
Durham
Thank you. I'll take all that into consideration. Today I decided to test the bike out again. It took 10 draws of the string to get a clean start. After a few seconds I lightly gave the bicycle throttle for about a second per turn. And then I opened the choke Which ran consistently for around 10 seconds before shutting off. I did the same thing again, with the throttle and starting up the bike, this time I gently screwed the idle screw in a little so that I would run a bit faster.. I managed to get a good two minutes of solid running. I will try again tomorrow gradually increasing the time I keep the motor running. Is this a good idea? What a good way to break in the motor be to start it up and do what I did periodically until it is able to run at a lower Idle?
 
knightscape

knightscape

Member
Jul 29, 2013
340
1
16
Maine
You typically want to break an engine in by actually running it under load. If the bike is functional, I'd fire it up, and hop on and ride. I bet it will run more than a few minutes when you're actually giving it the gas and riding, and would certainly be way more fun. :)
 
knightscape

knightscape

Member
Jul 29, 2013
340
1
16
Maine
Closed, it helps suck more fuel in to make fire, then once it fires and catches, open it up, and it should rev faster and smooth out the sounds.
 
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Donnyten

New Member
Jun 21, 2015
28
2
3
Durham
How consistent or ' smooth' should the motor be running? Seeks like it has it's 'ups and downs' where the motor seems to fluctuate slightly in sound and even at idle" unless I'm hearing something else'. Also, I noticed when riding, at the beginning , If I give the bike a little throttle while riding I hear this high pitched almost 'scccshhhhhhhhh' kind of noise, almost like something is rubbing against something . Also, what about the tires? Would it help to get bigger/wider/thicker tires? I did make the mistake of running it without oil when I first got it because the guy who built it didn't tell me he never put any fluids in it.
 
Last edited:
knightscape

knightscape

Member
Jul 29, 2013
340
1
16
Maine
There's a lot of stuff in what you just said, hunting in my experience usually indicates that you need to bump up the idle screw a touch. When it's idling, it should be nice and even with no hunting. The sounds you're describing could simply be your transmission (what kind of transmission have you got?), can you figure out generally where the noise is coming from? Running with no oil is definitely bad but if you only ran it for short bits like you were saying, you might not have damaged anything. There would likely have been at least some residual oil coating stuff in there, they fill them, run them, and drain them at the factory from my understanding.

Tires wouldn't have much effect on the engine, but might make it more comfortable to ride, helping to smooth out road buzz and bumps.
 
GoreWound

GoreWound

New Member
Dec 1, 2014
480
2
0
Canada
Donnyten said:
How consistent or ' smooth' should the motor be running? Seeks like it has it's 'ups and downs' where the motor seems to fluctuate slightly in sound and even at idle" unless I'm hearing something else'. Also, I noticed when riding, at the beginning , If I give the bike a little throttle while riding I hear this high pitched almost 'scccshhhhhhhhh' kind of noise, almost like something is rubbing against something . Also, what about the tires? Would it help to get bigger/wider/thicker tires? I did make the mistake of running it without oil when I first got it because the guy who built it didn't tell me he never put any fluids in it.
Click to expand...
sometimes bikes whitsle at high speeds, this is just the air being mad you are going through it. this can happen without a motor on it. that said it could also be an exhaust leak, this can be relatively easy to find with a sprayer bottle with some lightly soapy water in it (or if you are brave your hand) spritz the exhaust, if there is a leak you will see it (for the bravery method just hove your hand around the exhaust to feel for air moving, this engine has a fan under the pull start, so you will feel air coming off of that too) if something is rubbing that is really easy to check for: look around the bike near any part that moves and see if it has rubbed the bike, the paint will at least be scuffed by any touching making it easy to locate. fixing interference can be more dificult that finding it though, usually the method if different for each part that could be touching. the most likely part to rub is the chain though, this can be pretty easy to fix usually a tensioner or a couple of washers is all that is needed, though sometimes you may need to swap you rear tire or sprocket for a different one.

if you have an exhaust leak that can cause the uneven idle you have mentioned (when the air is leving through the leak it has less resitance on it causing the engnie to run a tiny bit faster for just a moment) but that uneven idle could be lots of things(the motor running too rich or lean for example, or even a loose throtle cable)

bigger tires (larger diameter) will have the effect of gearing down your bike, giving you more torque but lower speed, this can be corrected by gearing up the sprocket by a few teeth (that said this might be good, lower gearing takes the load off the engine somewhat)

wider tires can insulate you from the road more making your ride more cushiony, but unless you motor is mounted loose shouldnt effect how it runs at all, if you motor is mounted loose, tighten it!

unless you find them to be slipping out from under you or are falling apart the tires on your bike are probably just fine though.
 
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