I'm desperate, help required...please !

[streido]

You could be onto something with the jets getting dirty and blocked. Where did the crud come from and is there more? Probably.

You didnt use any sealant or anything on the carb when you took the bottom off did u? Only asking cos a long time ago i used gasket sealant on mine and next time i opened up the carb base the float chamber had bits of the sealant in it.

Did you check your fuel filter?

The oily mix in the airbox is normal too btw.

[streido]

Also, how does the plug look? Normal, lean or rich?

[KymcoManc]

I've just tried again on a fully charged battery & its the same pre carb clean, so it (the jets) must be clogged with crud again :-(

No I didn't use any sealant, just cleaned/blew out etc & replaced. The plug is alittle rich, would this cause a problem? If so how can I change this?

I'm just thinking the jets (or 1 of them) must be clogged again, but after cleaning i've no idea why & were from.

The only thing I know is after blowing the jets/cleaning etc the scooter ran fine, until I tried again after afew hours of being stood still.

Looks like I can only remove, inspect & clean again tomorrow? (Its too late in the evening now)

[KymcoManc]

I couldn't wait till tomorrow because its frustrating me.

Ok, i've removed the plug again & its very black & slightly wet, is this too rich?

Its obviously not right because i've cleaned it, checked for spark again (all good) put it back in & bike started 1st time. I've turned it off & re started many 4-5 times (all ok) & now left it running on tickover for the past 30 mins, its ticked over fine with no misfires or yo yo-ing etc & are now gonna switch it off. Fingers crossed it'll start in the morning, if not what do I do from here.

It must now only be the plug running a very black & slightly wet. What makes a plug so, is it just a case of changing the plug?

[old mod]

It's too rich, things to check, mixture screw, float level

[juice]

You may have a bad tank of gas . I would drain and rinse the tank , refill with fresh gas and add 1 oz.per gal seafoam , and replace the spark plug . Good luck .

[KymcoManc]

You may have a bad tank of gas . I would drain and rinse the tank , refill with fresh gas and add 1 oz.per gal seafoam , and replace the spark plug . Good luck .

Thanks to all posts, everyone has been a great help & its great to see the common bond of the US & UK on here :-)

Today's jobs.
1) order new spark plug, done √
2) remove existing plug, clean/replace
3) remove fuel tank, drain/clean/new fuel
4) start engine, warm it up till auto choke has done its job (revs drop), adjust idle speed & mixture screw on carb.

When plug arrives, tomrrow or day after (i hope)
5) replace plug (whats the gap settings, anyone know?)
6) Check idle speed/mixture screw adjust again
7) start up engine & hope i've covered everything to make my scoot run better than ever :-)

P.s on another note, if i get more air flow into the air box by means of extending/making bigger the existing hose, will this be of benefit? I understand i will just have to check/adjust the idle/mixture thats all?

[KymcoManc]

Jobs 1, 2, 3 & 4 done √

& running well. :-)

Jobs 5, 6 & 7 still to do (when plug arrives)

[juice]

If you increase the air flow you could see improved performance but you will have to rejet your carburator , running lean can cause overheating and engine damage . Good luck .

[KymcoManc]

If you increase the air flow you could see improved performance but you will have to rejet your carburator , running lean can cause overheating and engine damage . Good luck .

Thanks.

Well after doing jobs 1-4 earlier today then leaving the scooter to run great for a good while, it idled so sweet. NOW would you believe, I want to go on it & it won't start :-( :-(. Same again turning, but not firing.

I'm so frustrated with it now. I've taken out the plug & its still black & wet, ive cleaned & replaced, yet it still won't start. Tomorrow the new plug should arrive & so I feel all I can do is fit it & see.

I've read that once you turn off the engine, the auto choke dumps fuel ready for the next start. If this is correct? Could this be the problem? If so, can I do without the auto choke by removing it from the carb or simply un plugging its connecter?

Again any help is appreciated.

P.s once I fit the new plug & it starts, maybe a proper ride out to get fresh air in the air box will help? Instead of just starting & running in the garage on its centre stand?

[juice]

It sounds more like an intermittent electrical problem , maybe the stator or just the plug connector . I hope you find it soon .

[MaryK]

If the sparkplug gets black with carbon, then the engine is running too rich.

Several possibilities, but this may be due to the auto-choke staying on, either it may be broken or the temperature sensor
that controls it may be broken.

But you say that the idle speed reduces when the engine gets up to temperature, so some or all of that may be ok.

Another source to make the fuel mixture too rich is a very dirty air filter.

As long as you can clean the jets and it works, that points to trash in the gasoline as far as the starting problem.

So, the rich fuel mixture may be  a seperate problem from the starting.


Best of luck,

[juice]

He also stated that the plug was wet , that means the gas is not igniting . That is why I suspect electrical problems .

[KymcoManc]

I'm so pleased that i've got people on here helping me & with all your input it gives me confidence that i'll be able to sort it out :-)

What bugd me is that after doing jobs 1-4 yesterday morning, it started easily, I was able to let it warm up (atleast 10 mins) i was then able to adjust the idle speed & air/fuel mixture, then let it run for 20-30 mins & it ran so so sweet at revs just over cut off but enough so it wasn't chugging.
you'll understand I was so chuffed with myself.

Later in the day i came to start it & it wouldn't, turning over fine but not firing.
I remove plug to find it black & WET, I dry/clean it & replace but still no firing up :-(

Maybe the plug is knackered? I will know when I fit the new one.

Maybe other problems as you say on here? Its a dilemma but I won't be beaten :-). I can't be its my only transport currently & I don't have the funds to take it for repair at the scooter shop.

[streido]

The plug would be black and wet after the second time you tried when it didnt start, this would just be from the engine turning over and thriwing fuel into the chamber. Had it started the fuel wouldve burned off and the plug would be dry. Since it didnt fire up the fuel would just be pumping into the chamber and sitting there making the plug wet.

Did you check the spark plug connector end and spark plug cable? Could be a loose connection or damaged cable or bad end that makes sometimes but doesnt other times. What size main jet is in it? Is it derestricted? Any othet mods on it we should know about?