View Full Version : Scooter idle. Now what?
BASS-TREBLE
5th February 2009, 15:44
I need a lil help
The missus has a chinese 50cc 4t scooter and the thing wont run right.
Here's the story,
Firstly it stopped running around new years, we left it and went on a holiday to the south island for 3 weeks.
I figured the oil level was low enough to trigger the oil sensor and kill the engine.
Filed up oil and sure enough it went. Now it smokes a little more when cold and doesn't get its top speed anymore like it used to. Around 40kmh now.
It has an erratic idle when warm and wants to die, slower acceleration and when cruising under max speed and you give it some gas it dips in revs then accelerates.
I proceeded to clean carb bowl as I think its a fueling issue but nothing.
Replaced fuel filter, still nothing.
When replacing fuel filter I noticed that the line from tank is only dripping a little with fuel, now I don't know how the fuel system works on scooters with pumps or anything but It seemed weird for so little fuel to come out.
I looked under the scooter and there seemed to be a 'bell' like device under the tank with a 90 degree angle, could that be clogged and block the flow?
It looked like the manual fuel pump that is on toyota hiace vans that is used when installing fuel filters but smaller. Its the best i can compare it to, sorry.
The jetting was not touched and fuel is 1 week old.
I can only guess that the sitting time has made dirt clogg something.
Where to now?
Cheers
paturoa
5th February 2009, 18:01
The slow dripping doesn't sound right.
My cheap chinese quad had the same issue. It was a plastic tank and the hole was mostly blocked by plastic from the mold joins. So I had to pull off the tube from the tank and run the right sized drill bit "up the spout" to clear out the offending plastic.
The bell thing could be a one way valve.
Do you thing she ran it too low on oil and cooked / partially siezed it?
You going to Paeroa?
BASS-TREBLE
5th February 2009, 19:03
It had obviously run a lil low on oil, I don't know how low the sensor allows.
So you think it could be that the holes are plugged from sitting?
Yep Paeroa for sure, I'm dragging dad along too
BASS-TREBLE
7th February 2009, 06:39
Anyone?....
motorbyclist
7th February 2009, 07:44
does a chinese 50cc 4t scoot even have an oil sensor? would the sensor really be affecting the ignition? japanese bikes have an oil light but that won't affect the motor running in any way.
so assuming it hasn't been cooked, and not knowing what the insides of this generic scooter look like:
the fuel should come flowing out the fuel hose, check there shouldn't be a vacuum line running to the fuel tap. it's very likely the tank has blocked itself or the filter as mentioned earlier.
i assume it is a plain-jane slide carb. only thing to go wrong here is a blocked jet. check it isn't just partially blocked.
check the plug for colour and spark while you're there.
then if that doesn't fix it get back to us with a photo incase there's something obvious :)
BASS-TREBLE
7th February 2009, 12:26
Im sure it has an oil sensor because it just suddenly started when topped up.
The next thing I will do is clean the tank etc because when changine the fuel filter fuel pretty much dripped out of the line, ie. not a constant flow.
What are the symptoms of a partially seized motor?
Is it even possible?
As I've said, it boggs for a second or so when opening the throttle when cruising then catches up. So i'm leaning towards a fucked fuel path.
edit:
Its a small butterfly type carb with two jets coming out of the bowl. Everything seemed clean of dirt.
I does have one of those electric chokes, I may try taking that of and see if it changes anything.
craisin
7th February 2009, 21:15
like the other poster has stated about the vacunm hose that applies vacunm to a diaphram and the diaphram opens the tap. I came across this scenario on a ninja 250 that a mate had and their was a hole in the diaphram and the fuel didnt flow and it wouldnt start. And my friend didnt understand so i took the tank off and blocked the vacunm hose off and put a motormower tank on with zip-ties and fill it with gas and turned the tap on the little tank pushed the starter and it went. My friend understood then. Like the other poster i havent seen or know how you scooter works. Hope you understand:niceone:
craisin
7th February 2009, 21:27
the other poster from out west like me
motorbyclist
8th February 2009, 17:17
Im sure it has an oil sensor because it just suddenly started when topped up.
The next thing I will do is clean the tank etc because when changine the fuel filter fuel pretty much dripped out of the line, ie. not a constant flow.
What are the symptoms of a partially seized motor?
Is it even possible?
As I've said, it boggs for a second or so when opening the throttle when cruising then catches up. So i'm leaning towards a fucked fuel path.
edit:
Its a small butterfly type carb with two jets coming out of the bowl. Everything seemed clean of dirt.
I does have one of those electric chokes, I may try taking that of and see if it changes anything.
tell you what, these chinese filters can cause as many problems as they solve. in your case the filter could be clogged, and in my experience you can still get blocked jets from the filter itself falling apart.
of course, if fuel just dribbles out of the tank anyway, the problem is in the tank.
as for the carb, i'll need a pic. (electric choke?! really? they make those for scooters?!)
tell us how you get on.
if you can find out, exactly what model of scooter is this? got a link to where you bought it from? where is kiwifruit town?
a picture of the motor would be great because these chinese bikes largely all use the same one or two copies of a honda motor
and yes you can partially seize a motor in the sense that you ruin all the bearings/bushings through heat and wear, which then has an adverse effect on motor performance even when the oil is again present.
the other poster from out west like me
i assume that's me
craisin
8th February 2009, 21:07
tell you what, these chinese filters can cause as many problems as they solve. in your case the filter could be clogged, and in my experience you can still get blocked jets from the filter itself falling apart.
of course, if fuel just dribbles out of the tank anyway, the problem is in the tank.
as for the carb, i'll need a pic. (electric choke?! really? they make those for scooters?!)
tell us how you get on.
if you can find out, exactly what model of scooter is this? got a link to where you bought it from? where is kiwifruit town?
a picture of the motor would be great because these chinese bikes largely all use the same one or two copies of a honda motor
and yes you can partially seize a motor in the sense that you ruin all the bearings/bushings through heat and wear, which then has an adverse effect on motor performance even when the oil is again present.
i assume that's meyou assume right and I mean it in a good way
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