CRF250L With BigBore Kit and CBR300R ECU save to run?

[Bananapete]

Hello everyone,

I have just bought a '13 CRF250L with a 300cc BigBore Kit and hope someone can answer some of my questions.

As far as I know, the Bike has the following modifications:
-K&N High Flow Air Filter
-Full Arrow exhaust system from Italy
-300cc Big Bore Kit from ?Thailand?
-ECU from the CBR300R

As far as I can tell, the Airbox is still unmodified and all the emission stuff is still there and connected. The Bike does NOT have a power commander or an EJK Fuel Controller installed.

Allegedly, the Big Bore was installed just about a few hundred miles prior to selling the bike. So far, it runs really well and starts right up even below freezing.
So far I have only ridden the bike for about 30miles.

I have read that with a 300cc Kit you would need an EJK, but the the previous owner had just the ECU from the CBR300R installed. Now, even though the bike runs fine, I'm a bit scared that it might run to lean with just the CBR300R ECU with the additional 14cc more over the CBR.

What do you guys think, do I need an additional EJK or can the ECU System of the CBR300R cope with the BigBore cylinder? I dont plan on removing the emission stuff or modifying the airbox.

Also can someone idetify / recognize whats written on the side of the cylinder? Probably from the manufacturer of the Big Bore cylinder.

 

Thanks in advance.

[Evan D]

Sounds like a great bike. After a ride pull your spark plug and look at the color.

[Guest]

Thai script says 'Dome'

Wife says is a quite popular name. Is it a name in this case ???

In Shallah