first forgive me for my english, i'm french and i'll do my best !
I have my gw250 for one month now and since a few days, the engine is instable : i have an unstable idle and if i keep a constant speed, the problem is the same.
I just change the oil, oil filter, air filter, sparks and i checked the valve clearance.
This morning, i checked the fuel filter into the fuel pump and it was very dark. Do you think my problem comes from that ? Should i change the fuel filter ?
Thank you in advance for your answers