I had my local Mercruiser mechanic perform a valve job and replace the manifolds on my Baja 232 (stock 454 Mag MPI) as he suggested. When I got the boat back, it ran wonderfully smooth and felt quite strong, however the KNOCK SENSOR which has never errored before, kept creating alarms and automatically retarded the timing which has limited the RPMs to 4000.

The mechanic has no idea what has happened and has suggested he replace the sensor. He also thinks I should add a octane boost additive to the fuel and replace my new Bravo/1 22p prop which was cupped (23p) and balanced by ThrottleUp with the original stock Mirage/PLUS 23p.

I am not fully confident in this Mercruiser mechanics ability to solve this problem without weeks of blind effort and a great deal of expense. Although I plan to follow his suggestions, I was hoping that an OSO colleague could refer me to a quality Mercruiser mechanic in the Southern California area (Ventura or Los Angeles counties) who might be able to effectively solve this problem should the above actions prove unsuccessful. I do wish to keep the engine fully stock but would like to keep it operating properly at peak performance.
Any help would be greatly appreciated.

Matts mobile marine 714-369-7410
Straight shooter, knows high performance boats inside and out, great reputation, doesnt overcharge.. what else could you ask for?

My 2 cents - The heads were probably resurfaced/cut quiet a bit bringing the compression ratio up - possibly now detonating - thus setting the knock sensor off. Try backing the timing off and see if it quits.

I agree, Matts Mobile Marine or B&D Marine in El Monte...worth calling...

Thanks ..... I'll check with both referrals.
By chance, anyone know a resource in the Northern part of Los Angeles county?
<<< Ventura, Channel Islands, Marina del Rey >>>

Thats why I gave you the mobile guy. He has everything he needs in the truck. I have three boats listed that he has worked on and one was a full re-rig. VERY IMPRESSIVE

Thank you for the referral.
I'll call on Monday morning.