496 Ho
 

I have a 2002 Baja 342 Boss with 496 HO's.
The starboard engine is running 300 rpm's
slower than the port at WOT. The boat only
has 25 hours on it. I ran up each engine one
at a time on the hose in the driveway. There
is a noticeable difference like it is running on
7 cylinders when I goosed the throttle, it also
backfires through the exhaust when bringing
back the throttle. I am pulling the spark plugs
today to check them.
Any ideas? I am thinking ignition problem. As
always I appreciate any input or advice.

Jeff

I had a buddy with the same problem on a brand new 496HO. It ended up being just a loose spark plug wire. Could be the same thing.

I pulled all the spark plugs. All of them except for the number 1 cylinder looked good. It was glazed over and looked like that cylinder is running rich. I'm thinking the injector is staying open. Its going to the dealer Monday.