KNOT-RIGHT

Allow me to elaborate on " Quickly shut down engine safely as possible" We take the boat out on the bay and run engine to 5000 rpm for approx 60 seconds
roughly 90 mph in this case. Water permitting. Then we quickly bring the boat down to just before loosing plane. of course not swamping the transom Then Allowing minimal engine Idle we shut one engine down. Then allow the wake to settle. kill the last engine. this point we remove a plug from #1 cylinder (usually the lean one) and check the insulator color. Looking also for any small aluminum particles or balls. Depending on the age of the plugs This may take several runs to get a color on the insulator.


This may not be the preferred manor or the text book method of checking pugs in a marine environment. However it is the way that works for me.

Sometimes I forget how literally things are taken.

Gerry

PS
This it what your boat may look like when shutting down to quickly or slamming it in reverse with some good throttle. Some Mechanical problems here.

KNOT-RIGHT

Wait this just in these are the three that were running the boat above.

fstboater

I like power valves 5.5 front and rear 84 front 88 rear unless it has a very large cam and some compression it will get you in the ballpark set your secondaries to open later that will help with throttle response.