can any one help

[monkeymanjaso...]

Hi i need some help, my son has a moped,

And when he gets on it and tries and ride it, it rides well but i think once its warm you try and ride it again and it just keeps dying?

You pull the throttle and it dies, but when its
cold again it will run it will sit there idling but dies agen when you pull the throttle...

Can anyone help will be much appreciated???

Thanks

[Nope.]

The jet could be blocked. Remove the carb and clean out the main jet with some carb cleaner and some compressed air. If it has an Auto choke then check that.

Its also worth changing the spark plug and cleaning the air filter.

What model/make of moped is it? 2 Stroke or 4 Stroke?
____________________
Former: Derbi GP1 50, Sachs XTC 125, Suzuki GSXR 400 GK73A, Kawasaki ZX7R, Suzuki DR250, Yamaha RD350
Current: 2011 Yamaha XT660Z Ténéré, 2003 Yamaha YZR-R1 5PW (In Build), 2009 Kawasaki ZZR1400

[monkeymanjaso...]

Hi thanks for your reply,

I have changed the spark plug,
Changed the air filter,
And iv cleaned the carb out, but its still doing it,

I will check the automatic choke...

Its a honda melody 1981 deluxe, I think its a 2stroke

The only thing it could be is the automatic choke...

Thanks

[Nope.]

[monkeymanjaso...]

Hi thanks for your help again...

Where do i find the automatic choke..??

I have got 5 pipes coming from the carb, 2 pipes coming from the inlet manifold, 1 long pipe coming from the bottom of the engine which leads all the way up to the back of the bike,,,

2 pipes from the carb and 1 pipe from the inlet manifold go to the top of the engine..I can put a picture on of the engine if that helps...

Thanks

[Nope.]

You should be able to see a little box somewhere on the carb with a couple of wires coming from it. Something like this:

https://www.scooterfocus.com/scooter_carburetor_1.jpg


BTW I just realised that your the guy that started a thread about putting a larger engine in a Melody, I assume that you've gone off this idea now then?
____________________
Former: Derbi GP1 50, Sachs XTC 125, Suzuki GSXR 400 GK73A, Kawasaki ZX7R, Suzuki DR250, Yamaha RD350
Current: 2011 Yamaha XT660Z Ténéré, 2003 Yamaha YZR-R1 5PW (In Build), 2009 Kawasaki ZZR1400

[monkeymanjaso...]

https://i1091.photobucket.com/albums/i385/jasonhornsbury3249/9999999999999999999999999999999999.jpg
https://i1091.photobucket.com/albums/i385/jasonhornsbury3249/888888888888888888888888888888888888888882.jpg
https://i1091.photobucket.com/albums/i385/jasonhornsbury3249/77777777777777777777777777777777777777777777.jpg

i dont have that on the side of this carb so i dont no what it can be
now any more ideas......
iv gon of that idea bit stupid really dont no why i said it......

[monkeymanjaso...]

Any one else have any ideas...

[mccluskeyd]

Dear monkeymanjason,
have a look at this site, it has a few workshop manuals which may give you a clue as to how the carb is set up with its many rubber tubes.

The Honda Aero 50 seems the closest to your Melody, engine wise...


https://www.motorscooterguide.net/Honda/Aero50/Aero50.html

and,

https://www.motorscooterguide.net/Downloads/Downloads.html

Regards,
DMcC.

[monkeymanjaso...]

Hi thanks........

[Vincent]

Take the plug out and take a photo. If the auto choke is stuck on it should be sooty and black. If it's a lighter tan colour, it's probably fuel stavation. Blocked tap or something similar.
____________________
Space Is Deep

[finpos]

Choke problem sounds reasonable.

On your 3rd picture, to the left of the knurled cap where throttle cable enters the top of the carb there is a black plastic blob half hidden by one of the rubber tubes.

The blob covers the choke valve. It looks too small to be an auto choke - if it is an auto choke it will have an electrical connection on it - or if it's manual it will have a bowden cable. If it has neither that's probably the problem!

Edit - looking again it doesn't look particularly well seated whatever type it is....

f.

[Robby]

Could also be gummed up around the mixture screw, something you might have missed when cleaning the carb. To clean it up you need to remove the mixture screw/needle (unscrew it) and spray some carb cleaner into the hole using the nozzle on the can of cleaner. Clean the end of the needle using a clean cloth, then screw it in. The setting for it will be in the workshop manual, usually about 2 turns out. You screw it all the way in, then screw it out two turns.

There is usually a tiny spring and O ring where it seats into the carb, so don't lose them.

[lozza59]

hi just a guess!! you say if started from cold it runs fine yes? does it rev up cleanly etc? if you let it cool again (like an hour later) does it start and run fine? when it cuts out does it cough and splutter or just die? i had a similair issue with a bike i had and started playing with the carb but it was the regulator/rectifier i only realised once i saw the electrics playing up but took me a couple of days to notice the power fluctuations, might be worth a try. good luck with it

[monkeymanjaso...]

https://i1091.photobucket.com/albums/i385/jasonhornsbury3249/44444444444444444442.jpg
https://i1091.photobucket.com/albums/i385/jasonhornsbury3249/44444444444444444441.jpg
https://i1091.photobucket.com/albums/i385/jasonhornsbury3249/2222222222222222222.jpg
https://i1091.photobucket.com/albums/i385/jasonhornsbury3249/2222222222222222221.jpg

Hi,

Thats the old plug, i have took the carb out and cleaned it with carb cleaner and its been soaking in that all night, so i am going to put it back on and see if that works, If it carries on playing up i will video it and put it on,,,

It dont splutter it just does the dying noise like its running out of fuel

Thank to everyone trying to help...

[monkeymanjaso...]

bad news it still doing it heres a video let me no what you think...........

https://www.youtube.com/watch?v=wcY8PyEM9d0

[finpos]

Ok, well the black plastic thing that is "L" shaped and looks like it has a "4" on it is definitely the choke control and it looks like it's designed to take a bowden cable (which I presume is missing...). It's not an auto choke.

You need to remove it (probably unscrews) and inside there there should be a little spring with a plunger. The plunger should go into a little hole in the carb under spring pressure, and when you pull on the (non-existent?) cable it will be withdrawn. When it's in the hole it's blocking the enrichment (choke) circuit in the carb and when it's out it's letting extra fuel through to start the engine when cold.

The spring and plunger are usually part of the cable itself.

So, the two possibilities are:

1) there is no spring and plunger in there, so the choke is permanently on.

2) There is a spring and plunger in there, in which case there is no cable to operate it and the choke is permanently off. In which case somebody may have adjusted the mixture screw to make it run stupid rich all the time just to start the engine.

f.

[monkeymanjaso...]

[finpos]

In that case I have no idea how it works!

Take it off anyway, take pics of what's inside, the pipes, box and where it connects to on the engine.

F.

[monkeymanjaso...]

[monkeymanjaso...]

[finpos]

yes I see the tubes now, what is of interest its what they carry.

One other thing you could try ia to run the engine until it starts to bog down and then adjust the mixture screw to lean it out and see if it picks up - count the turns so you can put out back where it was.

F.

[monkeymanjaso...]

[cb1rocket]

ignore the garage they havent a clue either. Its def carb related thats for sure

[finpos]

Never like to disagree with professionals but would tend to agree with the above. The only sticky ring you'll have is your own when you get the bill.

Next thing to try -

Pull the tube off the plastic thing marked "4".
Cold engine - should start as normal.

With the tube disconnected nothing now should be actuating the choke valve, so it should not move and the engine will keep running and not bog down*. One can only hope. If it still bogs down then it's not the choke.

Out of personal fascination, what manner of air is in the tube "4":
a) Vacuum?
b) First cold then hot air that has been blown by the fan over the cylinder?
c) other??

*edit - actually that's not true - once it warms up it should be running with the choke on so it'll be rich as hell. But hopefully it'll do something different.

f.