Need Mercruiser help in Channel Islands Harbor

[Impulsive]

I had my local Mercruiser mechanic perform a valve job and replace the exhaust 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, keeps creating alarms and automatically retardeds the timing which has limited the RPMs to 4000.
The mechanic has no idea what has happened and has replaced the knock sensor. He also asked my to add an 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 which I have also done.
Nothing has changed .....
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. I was hoping that a fellow Hot Boater could refer me to a quality Mercruiser mechanic who works in the Channel Islands Harbor or Ventura areas who might be able to effectively solve this problem. I do wish to keep the engine fully stock but would like to keep it operating properly at peak performance.
Any referrals would be greatly appreciated.
Thanks
Bill

[Liquid Courage]

So-Cal Speed and Marine
661-644-3177

[acatitude]

are you sure the knock senser doesnt need to be reset

[Impulsive]

are you sure the knock senser doesnt need to be reset
No ..... and I don't think this mechanic knows either.
How do you reset the Knock Sensor on a 454 Mag?

[TheCarDudes]

Try Hi-Tech Marine Simi Valley. 805-583-2656. Jim has worked on several of my boats. Good work and fair prices. He is a also a mercruiser dealer.

[jimslade]

You can't reset a knock sensor. Firstly, if you have ran the engine at least a couple of hours. pull the plugs and read them. Check to make sure the right plugs have been installed. To hot a plug will cause preignition.. I have also seen platinum plugs causing preignition.

[acatitude]

well maybe recalibrate is a better word.... maybe there are different types of knock sensers, but im sure some can be reset or calibreted some how... at least thats what I thought sorry if wrong

[98 Vector 21]

Give Alexi a call at Boostpower USA, Newbury Park 805-376-6077

[HTRDLNCN]

Knock sensor can also be set off by other metallic sounds..
If the heads were redone and something now makes a noise that sounds similiar to the sensor (loose rocker, improper valvetrain geometry causing contact,whatever) this could be whats setting off the sensor ..

[randy77zt]

if it had a valve job done on it its probably a loose rocker arm-the knock sensor is picking it up.