Scooter starting issue

[jjcd]

Hi all,

Haven't posted in here much but got my Mod 1 next month so may be here more often once I've bought a bike!

I have a 125cc scooter that I use for commuting to the station but it has become a bit of a pain...

Symptoms:

1. Used to start nicely (instantly) on the button and would then idle happily. However in recent months it has become sluggish to start on the button - it is now almost impossible to start on the button. It turns over well but wont fire up.
2. Will start on the kick start - but only after turning over a few times on the button.
3. Doesn't idle as nicely to begin with since the weather got cooler - this could be the carb needing adjusting?
4. Runs nicely once warm - ALSO starts straight away on the button when warm..

So far I have changed:
- Battery
- Spark plug
- Electronic auto choke

Any ideas about what I should change/adjust? Appreciate any help however small!

[Krikkit]

Poor cold start and Isle would indicate a carb issue to me, when did it last start cleanly?

[A500leroy]

Earth straps rusty?

[Moulder]

What scooter is it?

For my speculative punt I am going for valve clearances.

[Rubin215]

Moulder said:

What scooter is it?

For my speculative punt I am going for valve clearances.

Yup, my money is on valves too.

[jjcd]

Its a Chinese Direct Bikes 125cc - I know I should've got a Honda/Yamaha but I bought it purely as a cheap way to get to the station and its done that for 5000 miles so I can't complain too much..

I dont think its the earth strap but will check again.

I'll have a look at the valve clearances - thanks!

It hasn't started cleanly for several months so I was considering changing the carb as replacements are cheap but not set on that yet..

Any other ideas?

[jjcd]

Also does anyone know the valve clearance for a 125cc? I've found 0.003 - 0.005mm online?

[Rubin215]

jjcd said:

Its a Chinese Direct Bikes 125cc - I know I should've got a Honda/Yamaha but I bought it purely as a cheap way to get to the station and its done that for 5000 miles so I can't complain too much..

I dont think its the earth strap but will check again.

I'll have a look at the valve clearances - thanks!

It hasn't started cleanly for several months so I was considering changing the carb as replacements are cheap but not set on that yet..

Any other ideas?

Definitely valve clearances if it's Chinese, they are notorious for it.

[jjcd]

Excellent - I'll have a look over the weekend - thanks!

[Krikkit]

jjcd said:

Also does anyone know the valve clearance for a 125cc? I've found 0.003 - 0.005mm online?

Those will be in inches not mm. I'd go 0.08-0.1mm (~4 thou) inlet and 0.15-0.2mm (6-8 thou) exhaust. Exhaust should usually be larger clearance as it runs hotter, hence the warm lash will reduce more than the inlet valve.

Edited by Krikkit on Friday 14th February 17:19

[jjcd]

Thanks, that makes sense! I'll report back after the weekend..

[jjcd]

I owe you all!

The valve clearances were pretty much non existent - both now set correctly and it starts and runs better than it ever has!

Thank you all

[Pothole]

Excellent. Well done, all.

[Krikkit]

Great result, nice and easy

[jjcd]

Great result all!

[bimsb6]

I was going to say valves but got beaten to it ! Guy at work had a chinese scooter with the same symptoms , looking at the service book it was supposed to be serviced every 1000km ! 5000miles in and valves had never been done .