HPDI Spark Plug

[dtarules]

I was running the river today at 5300 RPMS 57 MPH 6am the motor was just humming along and all the sudden it gets ruff. I think I hit something and its messed up my prop so I stop and check it. The prop is fine. Crank the motor back up and it vitrates like hell and sounds like a cylinder is down. I dont want to cause damage so I got a tow. check the plugs and the top left plug is all black. What could cause this? all of the ohter plugs look great. the plugs have less than 5 months use.

[Reata210]

Could be bad fuel or a fouled plug. I would check compression, change plugs and run it again.

[Vyper202]

On the HDPI, change your plugs after the break in period and then every 50 hours after that...Ive got 230 hours on mine and havent fouled a plug yet.