These guys and the one's at the 460 forum told me not to use them.   I already had them so in they went.  They worked all summer till the last run when we leaned on it pretty hard to beat a storm down the lake.
I had the timing up to 38 degrees total.   This is the result.   It now has probe flat tops.

If it were me I would buy a couple gallons of cheap motor oil.   Fill that sucker to the top of the valve covers and pump the cylinders full with an oil gun.   Work the engine back and forth a bit to move the pistons in the bore to make sure everything is exposed to the new oil.

I'd let it sit over night full of oil then drain it.   Turn the engine over by hand without plugs to pump out the oil from the cylinders then go from there.

Do you have any idea how deep the engine was submerged?

Good luck

With the cobra jet ports in the manifold you'll need the cobra jet intake gasket.   Bigger gasket seals over smaller ports but smaller gasket won't seal over bigger port opening 

If you're low on oil you aren't sucking IN water.   Why not change the oil again and see
what's actually IN there?

Gotta disagree with the stock pan with a high vol oil pump.   My 1977 cv23 jet came standard with
a 6 quart front sump pan.   I put in the hi vol melling pump in about 1980.

Never had an oil pressure issue till I put on the milodon 10 quart marine pan.   Go figure 

This is a 460 but apples to oranges they are pretty much equal.

Stock your engine probably made between 320 to 350 HP.

You think something like that would get it low enough being measured at 4'?

These laws are out of control!    You guys are being had   

Measuring the sound at 4' has to be the dumbest thing I've ever heard.   Who in their right mind would come up with a regulation like that but an idiot paper pusher.

 Anyone within 4' of the back of my boat that would be offended would already be drowned.    

You would think it would be measured from at least 50'   Notice the Deisel truck listed below, they are on the street every day,  right beside a lot more people than will ever be exposed to boat exhaust.  It's higher and measured at 30'. 

I wonder why they didn't tell them to muffle it 

That enforcment level and distance is just insane and is nothing less than harassment 

Some average levels are listed below.
 Threshold of hearing
 0 dB
 
 Motorcycle (30 feet)  Here again, everyday exposure by anyone on the side walks
 88 dB
 
Rustling leaves
 20 dB
 
 Foodblender (3 feet)  Funny this can make more noise than the human can bare from a boat engine!
 90 dB
 
Quiet whisper (3 feet)
 30 dB
 
 Subway (inside)  Good lord!  How can these people stand it.  They'll all be deaf 
 94 dB
 
Quiet home
 40 dB
 
 Diesel truck (30 feet)   
 100 dB
 
Quiet street
 50 dB
 
 Power mower (3 feet)    Shut them down!   
 107 dB
 
Normal conversation
 60 dB
 
 Pneumatic riveter (3 feet)
 115 dB
 
Inside car
 70 dB
 
 Chainsaw ( 10 feet)
 117 dB
 
Loud singing (3 feet)
 75 dB
 
 Amplified Rock and Roll (6 feet)
 120 dB
 
Automobile (25 feet)
 80 dB
 
 Jet plane (100 feet)
 130 dB
 

Typical average decibel levels (dBA) of some common sounds

I have a CV 23 Glastron carlson.   I put on a place diverter and the large rudder and it steers great at idle etc.

My son bought an identical boat to mine with the place diverter without a rudder.   It took one trip out to order the rudder.  Don't let anyone fool you.   Put on the large rudder and you'll never regret it.

Oh and if you cut the power and turn the steering wheel you will have some steering unlike the rudderless.  That is first hand testing of identical boats, the rudderless also had more severe
jet wander in the no wake zone.

I hope this helps

Does it have a vacuum gauge?   One other thing a friend told me to try...  have your wife
or girl friend hold a plug wire while you crank it over.

If she screams and chases you two blocks spark is good
If she curses and walks away check for weak spark

 

Sweet wheel.

Question for everyone...

Can you adjust the wheel to center it with the jet ?

 I screwed up my steering cable install.  Now my wheel look llike I'm going left when I'm going straight, sucks !

That adjustment is made at the jet.  The nut right below the red cable.  The slide area is your adjustmemt.
Is yours set up that way?

Thank you, same for you!
What intake is that you're using?

The main thing you got to watch for in the big HP is the cam.A lot of cam will destroy your out drive.Its when you put it in gear from forward to reverse,high idle because of the big cam.

I thought we were talking jet boat?  They're gear exempt.   

Take off the coil wire and turn it over.  If the starter antics go away it proves
your timing is to advanced.    

If you fire to early the engine is fighting your starter.

Back off the timing a bit then try it again.   Turn the distributor CCW about 1/2 inch and see
if that doesn't change it's attitude a bit.  

  

Check your PMs

Thank you for that.   Now next issue, will these manifolds clear tall valve covers?  I'm running
a stud girdle.   Any one know for sure if they will clear?