Sparkplugs problem

  friends!

Could you give a hand?
I have a M50 Vz800 2006, I have a serious problems with spark plugs. Every day I have to change both spark plugs, completely dirty!
My bike worked good  with DPR8EA9, but not now, I  tried  with DPR7EA9, DPR6EA9, the same problem. I changed the ignition coil assy, the control unit F1. Until now.. the same problem! I have no idea what happened!

Thanks for your help! 
 

Hi Luis, dirty air filter? Valve clearance/seals? Piston rings? Any more info on the bike?,eg, mileage, state of tune and service etc, does it run then cut out due to fouling? not start at all? the more info the better, You've tried hotter and colder running plugs and changed the ignition and FI, Is there a good spark? did you change the injectors or just the FI unit?, FI unit, as in processor or ECU? Any info helps thanks.

Sounds like an injector issue, over fuelling. That goes back to FI system, get brain into gear and have a deep think!

Hello Luis,
I agree with George here, fuelling fault and Sim dirty air filter,,, Do you have any fault codes flashing F1 light on the clock ?.

Hello friends! thanks for you help!!
No codes at all, I clean the filter K/n. my bike has 54 000 milles aprox. I didnt chance the inyectors, I just cleaned two times, valves adjusted. I don´t change the Pistons rings until now.
At minimun the bike works ok.
Thanks a lot ! Sim, George and John! I appreciate your help!