Benzhou MotorStar 50cc [CHINA] wont start By xscottiex (Read 3,743 times)

[xscottiex]

Greetings guys,

I have checked over the threads and played for over a week now, i figure its time i post this problem is much the same as everyone elses but i have done everything i can.

My scooter wont start, it was working fine then i stored it away for 6months now it wont start.
I have changes the fuel filter and i have drained the tank and put new fuel in, i have also changed spark plug and changed battery and drained oil and put new oil in (20w - 50 .. is that to think??)

It sounds like it trys to click over but it just wont, it will not kick start or electric start.

From my own trouble shooting i think i have a compression problem, for if i take the line from the petcock that runs into carb and put it into a jar only tiny drips of fuel come out when i start / or kick start, only the tiniest drops... But if i take the vacuum line from the pitcock and suck on it lots of fuel pours out... So i figured i would bypass pitcock with a gravity fed line but still no luck, even if i pour fuel into the line there is no luck starting it (EDIT: ignore that, now it seems to shoot out when i kick it.... fuel that is)

What could this problem be? Im sure its compression problem but i bypassed the pitcock and expected it to work, no avail This is driving me nuts i just cant figure it out....
I have checked spark plug gets spark and it does, and starter kicks over so im sure its not solenoid problem, im positive its a fuel or compression problem... where to from here lads?

-scott

edit:
i must add that when i go to kick it , it feels very week, but my mate said 50cc's normally do feel weak when you kick them and he said he can feel compression in the kick start.... now im even more confused.

edit:
i checked line going from pitcock to carb and its not blocked... So maybe its a carb problem?

edit:
ok im going to try the carb tests now... like below:

CHECK CARB:

First turn the Fuel Ratio Screw Clockwise until it stops and then turn it out Counter Clockwise 2 ½ turns

And try to start it.

A. If it does not want to start get a paper cup and put in about teaspoon of gas. Take the Vacuum hose off the Intake Manifold squeeze the paper cup and make a point and pour the little bit of gas straight into the Vacuum hose and connect the hose back onto the intake manifold. Now try to start it.

a. If it attempts to start or start and die now we know gas is not being sucked out from the carb bowl





can anyone tell me is that dangerous i mean if i pour fuel into the vacuum house that sounds like its going to mess things up 0_o, if i get the go ahead ill try that test but im a bit paranoid about it....

[justbuggin2]

ok you said you have spark was that holding the plug to the motor or frame ? you have fuel getting to the carb have you cleaned the carb the are many tiny ports that have to be clear or you will not get fuel into the motor when you check the plug was it wet or dry

[alleyoop]

No that is fine THOSE ARE MY TEST INSTRUCTIONS(HAHA). Nothing will happend but what we are doing is putting a little gas right down the intake JUST AS IF IT SUCKED FUEL IN byitself.

To test compression and see if it is descent enough for the motor to run TAKE THE SPARK PLUG OUT and STICK YOU FINGER in the hold and hold it FIRMLY. THEN OPEN THE THROTTLE WIDE OPEN AND HOLD IT WHILE YOU CRANK IT. If it blows your finger off the hole it has enough compression for to start and run. If it doesn't then you have a problem.
Alleyoop

P.S if you live in COLDER CLIMATE NOT FLORIDA 20w50 is to heavy,
put in 10w40 oil year round cold or hot.
20w50 will turn like honey in cold weather.

[xscottiex]

Mar 3, 2013 23:37:41 GMT -6 justbuggin2 said:

ok you said you have spark was that holding the plug to the motor or frame ? you have fuel getting to the carb have you cleaned the carb the are many tiny ports that have to be clear or you will not get fuel into the motor when you check the plug was it wet or dry

I had the plug plugged into lead and then sat it on the metal body of the motor and then turned it over and there was a spark, it wasnt wet but it did have some black stuff on it. So best way to clean carb is with some carb spray?

[xscottiex]

Mar 3, 2013 23:43:02 GMT -6 alleyoop said:

No that is fine THOSE ARE MY TEST INSTRUCTIONS(HAHA). Nothing will happend but what we are doing is putting a little gas right down the intake JUST AS IF IT SUCKED FUEL IN byitself.

To test compression and see if it is descent enough for the motor to run TAKE THE SPARK PLUG OUT and STICK YOU FINGER in the hold and hold it FIRMLY. THEN OPEN THE THROTTLE WIDE OPEN AND HOLD IT WHILE YOU CRANK IT. If it blows your finger off the hole it has enough compression for to start and run. If it doesn't then you have a problem.
Alleyoop

P.S if you live in COLDER CLIMATE NOT FLORIDA 20w50 is to heavy,
put in 10w40 oil year round cold or hot.
20w50 will turn like honey in cold weather.

Thanks for the replay mate, i live in QLD Australia, very hot here I will try the carb test and compresion test now and get back to you, may i just confirm i poor a teaspoon of fuel into the pipe that i suck on to get the pitcock working? that is the vacume pipe yes? With second test i stick my finger into the spot where the plug goes and if it blows my finger off its all good? sorry just want to confirm i dont wanna hurt myself haha, new to this.

Thanks in advance for your help.
-scott

[alleyoop]

YEs, hold the VACUUM HOSE UP SO A LITTLE BIT OF GAS FLOW INTO THE INTAKE then reconnect the hose and see if it FIRES. IF it fires then we know no fuel is being sucked in so the next step is check your compression with the finger trick unless you have a Compression gauge then use that.
Don't worry it will not BLOW your finger all the way out it will just blow it off the hole. If you just feel a little pressure on your finger then your low on compression.

Then you can try and check your VALVES and see if the are tight and loosen compression. Set them to .004 both of them.
Alleyoop

[xscottiex]

Mate Thanks!!
She fired over when i put some fuel in vacuume line and she ideled for a few seconds and then died...
this is the best i have got in weeks !! So now we know the fuel isnt being sucked in?
so now i check compression by taking out spark plug , and putting my finger in the hole where spark plug goes into the engine, then turning it over and feeling what happens??

Edit: strange thing, the big part on the carb that attaches to one side where the vacuum pipe comes from is kinda lifeted and moved over to the side, there seems to be a couple ml gap where the seal has lifted up, could this be a problem? ill get a pic of it now.

can i ask you if these are safe to do? a guy is telling me to do some stuff to scooter but it sounds dangerous so i wanna check with you first.

thescooterprofessor.proboards.com/index.cgi?action=display&board=chineseclassroom&thread=2418&page=1

[alleyoop]

FANTASTIC!! if that is the case that could cause no suction of the fuel if you have a bad AIR LEAK. So button it all first make sure everything is nice and tight Clamps on the Carb both sides etc.. as well as the INTAKE CONNECTION TO THE MOTOR and give that at shot.
Alleyoop

[xscottiex]

hey ally,

could this be the problem:





should i put some gafer tape over that hole and try start it?

-scott

[alleyoop]

No that is nothing all that looks good, that the intake goes all the way down and mounts onto the motor that is just a little around the shroud where it blows air under there to cool the motor.

So since it was sitting for so long and you already turned the fuel ration closed and opened it up 2 2 1/2 turns out the Carb is probably varnished up and the Pilot jet and its passage may be are probably clogged. You could check if the CARB is getting fuel, take the DRAIN HOSE and put a container and open the drain and see if fuel comes out of the bowl. ABOUT 2ozs should come out if the carb bowl is full.
Alleyoop

[beakeyozz]

l have a spare carby if needed in brisbane too

[xscottiex]

Ok yes i turned it back and it didnt start so i put 1 teaspoon of petrol into the vacuum pipe and it started then died.
So this means its not sucking fuel from the bowl? What am i looking for when i look for the drain screw? i found the drain hose i think but how do i open it up?

thanks again for your help, this is fantastic we are making progress.
-scott

[alleyoop]

If the hose is wrapped with wire then the drain screw is on the end of the hose. If not the drain screw is right next to the hose where it attachs to the carb. You just loosen it up COUNTER CLOCKWISE do not unscrew it out just loosen it up fuel should come out the hose.
Alleyoop

[xscottiex]

Mar 4, 2013 0:36:37 GMT -6 beakeyozz said:

l have a spare carby if needed in brisbane too

mate thats fantastic ill keep trouble shooting for now, but i might have to hit you up on that offer soon if i cant figure this out. ill keep you updated, once again thanks for the offer very awesome of you.

[alleyoop]

Here is what to do to clean the carb.
1. Unscrew the Carb bowl and this is what you will see.



2.Take the Pilot jet out and Main jet they just screw out.
3. Clean the Jets make sure you can see daylight through them.
4. Get a CARB CLEANER they come with a LONG THIN STRAW and stick that into the PILOT JET HOLE WITHOUT THE JET IN.

When you Spray into the PILOT JET HOLE here is where spray should come out:



When you Spray into the MAIN JET HOLE here is where spray should come out: