My yamaha 250 (s250TURU) starts stalling when i go for the wot. I decided to change the fuel lines, clean out fuel tank, changed fuel filter water seperator, installed new low pressure fuel pomps, cleaned carbs, checked psi on all cylinders and were even on all 6. Installed 6 new sparkplugs and took it out for a test run. Still the same thing. Stalls when going for wot. Took it out and checked the sparkplugs. The left block the 3 new sparkplugs were clean ( the run was for about 3 minutes). The right block the 3 new sparkplugs were completely black and oily. Anny suggestion on what may cause this and where i should look next to fix this problem? Thanks in advance.
