EC250 2T Dying after starting

[GGRide]

Howdy,
I have a Gas Gas EC 250 from 2000~5 in 2T, and I have some problems with it.

It starts very easily, even if I leave it for 1 year, I just have to remove the spark plug, wipe it a little and hit the pedal 2-3 times and it starts. But if I drive it for some time, 15-30 min, it dies suddenly *or stops accelerating* and doesn't start again, and if it starts, it starts very hard (40-50 pedals).

I once had problems with the Coil, a screw came loose and after I tightened it it went ok.
I don't remember that well, but it seems that the spark was weak.

Could the Coil fail like that? I'm thinking of buying an original one and trying it on.

Or should it be the carburetor? It has a Keihin carburetor, and as far as I know, those are quite good and don't break down like that.

 

[Anders]

sounds like it get problems when hot. My bet would be on the stator, or at least the ignition pickup.

The coil may also fail, but the stator is closer to the heat source.

How does the coil's earth connection on rad frame look ? Rusty?

Sent fra min YAL-L21 via Tapatalk

 

[GGRide]

I left a link with pictures,and the wiring it's very bad,I want to re-wire some connections with the same color,because everything has another color and it's not so "waterproof".

IMGUR
And I don't think I know where the earth is,I think it's that wire with the coil.

Because I can't find a Manual online,i'm not really sure what year the bike is,but I really want to make it again like new,even if it drinks gasoline like us drinking water

* VTREC250001000811* A 1006 - Here is the VIN,if you can tell,I don't know how to decode it

 

[(F5)]

I'm hearing stator. Just found the receipt for mine last week. It's not uncommon for an older bike, same part used on ktm of era. Plenty aftermarket available online.

 

[Anders]

I left a link with pictures,and the wiring it's very bad,I want to re-wire some connections with the same color,because everything has another color and it's not so "waterproof".

IMGUR
And I don't think I know where the earth is,I think it's that wire with the coil.

Because I can't find a Manual online,i'm not really sure what year the bike is,but I really want to make it again like new,even if it drinks gasoline like us drinking water

* VTREC250001000811* A 1006 - Here is the VIN,if you can tell,I don't know how to decode it

Sorry, I cannot decode the VIN, but others here might. If you show us a picture of the bike we should be able to tell you the approx model year.

The coil is earthed through it's screws. Please check that the mounting areas on the frame (where the coil is clamped to the frame via the screws) are free of rust and seem to be a good contact point.

 

[GGRide]

Hi,
IMGUR

So thats the bike,I think it's a 2001.

And the Earthed screw you said marked with red,that's directly put on the coil with earth touching the coil. But that's like that for long a time,before me having problems with it,and if you can see,the screw it's new,cause i've put new screws at some point.

 

[(F5)]

If you look at your rims they will have a date code on them. You would expect many 2001s to have been built in 2000 or 2001.

 

[A_Pit]

Hi all,

I have not the same bike and not exactly the same problem, but everything is close and fits to topic name.

Bike: EC250 2018 but with two-mapped ECU

Problem: Starts normally but dies after 10-15 seconds.

What have tried:
replaced ignition coil - no effect, same behaviour;
replaced pick-up coil - no effect, same behaviour;
disconnected everything except stator-ecu-ignition - no effect, same behaviour;

In my understanding now I have only two "suspects" - ECU or stator.

Does anyone have suggestions how to distinguish which of them to order first?

Video of stating attempt with spark tester attached -

 

[(F5)]

Stators have a lifetime. As insulation breaks down they work when cold and start internally shorting.
If you got keen you could measure the resistance then put it in a heat chamber and measure again.

 

[A_Pit]

Stators have a lifetime. As insulation breaks down they work when cold and start internally shorting.
If you got keen you could measure the resistance then put it in a heat chamber and measure again.

Thanks for suggestion!
I have tried to heat up the stator with a heatgun till temperature when I can just shortly touch it with my hand and I don't see any sudden resistance drop. It increases gradually from 16,4 Ohm (room temperature) to 19,5 Ohm (can barely touch). Resistance to the body remains open circuit.
Workshop manual says that this number should be 12.2 Ohm with 20% tolerance, but I'm not sure if I can trust it because even wire colors are not the same as on actual stator.

 

[Anders]

Are you sure its the ignition that's to blame? Could it have to do with the carb?
How is the ground connection for the coil? I had something similar once and traced back to a rusty ground connection for the coil.

 

[A_Pit]

Are you sure its the ignition that's to blame? Could it have to do with the carb?
How is the ground connection for the coil? I had something similar once and traced back to a rusty ground connection for the coil.

Hi Anders!
Thanks for your reply!
Carb was the first thing I have checked (several times) because it is the cheapest possible fix. But unfortunately, it doesn't help.
In addition, on video it looks for me that the spark is not always there - disappears, then appears again, then bike dies. So my understanding is that it is a ignition issue.
Connections was the second thing I have checked. Also ignition coil is new, replaced as an attept to fix the issue, so connections around it has been checked. Unfortunately, it doesn't help.
Could be that I haven't noticed something, but I would say that it is quite unlikely.