I have a 2008 230SX High Output. I have not run the engines even 100 hours and have had the initial service. Recently, I couldn't start one engine, when it did start it ran very rough and conked out frequently. The engine would not reach 10K RPM and would overheat. The other engine also would start to overheat. I took it to the dealer and it was serviced; the only things they did was replace all 8 spark plugs which they have me; all are fouled. Any ideas how the plugs could be fouled so quickly? Thanks.
