Won't restart after running

[pmarth]

My 125 will only start with starting fluid. It runs as long as you want, but shut it off and it won't restart.    Following has been done: new plug, new carburetor (cleaned the OEM and replaced it, same problem),  new petcock, new air cleaner.  Any ideas?

[tortoise]

No mention of checking valve clearance?

[pmarth]

No, didn't check the valves since it only has 750km.

[Stig / Major Tom]

No, didn't check the valves since it only has 750km.

Yeah, we're throwing pasta on the wall when you don't give us any information about the scooter.
Year, miles, new to you or new, previous issues, wrecked recently, what country, modifications, ....etc.
Stig

[pmarth]

Sorry, it's a 2014 Agility 125.  Bought new to carry on the back of my motorhome.  At 750KM, it doesn't get ridden a lot.  I have cleaned the carb and also tried different ones, no help.  New plug, petcock, fuel filter and of course new fuel.  Only Starts with starter fluid and will run all day, but the won't restart.  Battery is fully charged.  Looking for other ideas.

[tortoise]

Battery is fully charged.

Test cranking volts.

[Viper254]

Hi bud,

It's not unusual for the valves to be too tight out of the crate. I'd really recommend checking them anyway as a first port of call. I think they're really likely to be too tight.

[scooterfan]

Hi bud,

It's not unusual for the valves to be too tight out of the crate. I'd really recommend checking them anyway as a first port of call. I think they're really likely to be too tight.

I fully agree. This is a tipical example of valve clearance gaps which are too small. The engine will start easily and perform normally when cold - but once the engine is warm the engine loses power and the engine battles to start.

If valve clearances are correct, the engine will start just as easy as when cold.

Check those valve clearances guys - there is no guarrantee that the clearances will be correct, even when the engine is brand new.  I’ve seen this many times on different brands of engines on the market during my lifetime - including the best on the market.
Think “mass production”. All engines are manufactured in large numbers each year. Incorrect clearance settings are not unusual.

[Stig / Major Tom]

OP has a no start - cold or hot....NO start.
Let's keep thinking. .....
Stig

[CROSSBOLT]

Sits on back of motor home a lot...750 km since new...2014...now 2018....runs with start fluid dumped in its throat...won't start with on board fuel....! IT IS NOT GETTING FUEL!! 1. Fuel in tank?(sorry, had to ask!) 2. vacuum operated fuel valve opening? 3. tiny jets in carb plugged? Bet it is one or more of these three. The key is the information you gave after Stig asked. OK, now you gotta check all that. We can't wait to hear your results!

[scooterfan]

Sits on back of motor home a lot...750 km since new...2014...now 2018....runs with start fluid dumped in its throat...won't start with on board fuel....! IT IS NOT GETTING FUEL!! 1. Fuel in tank?(sorry, had to ask!) 2. vacuum operated fuel valve opening? 3. tiny jets in carb plugged? Bet it is one or more of these three. The key is the information you gave after Stig asked. OK, now you gotta check all that. We can't wait to hear your results!

So if the carb “IS NOT GETTING FUEL”....... where is the fuel suddenly coming from once he got it started with start fluid ?
Does he keep on dumping start fluid down the scoot’s throat to “keep on running all day” ?

I repeat - this is a typical symtom  when valve clearance gaps are too small.

[scooterfan]

OP has a no start - cold or hot....NO start.
Let's keep thinking. .....
Stig

Just have another look at the heading, as well as his comments.

The heading says “ Won’t restart after running “. He never said he experienced a “cold or hot” no start  situation.
To my mind he was referred to a RESTART problem - after the scoot was “running all day”. Common sense tells me the engine will be hot after running all day.

[Stig / Major Tom]

Or, "My 125 will only start with starting fluid." ..... And, "Only Starts with starter fluid and will run all day," = cold start, too, to me.


Wholelotta things start with starting fluid squirt - and keep on running. Probably half the cars in my one horse town start this way in the winter.
But it ain't getting gas or good hot spark when needed at a start.

Maybe it is the valves. I'm certainly no expert.
Stig

[CROSSBOLT]

So if the carb “IS NOT GETTING FUEL”....... where is the fuel suddenly coming from once he got it started with start fluid ?
Does he keep on dumping start fluid down the scoot’s throat to “keep on running all day” ?

I repeat - this is a typical symtom  when valve clearance gaps are too small.

Yup, I shore missed that one! Bystarter!