Mercury black max 200

[Tim W]

My Uncle has a 1989 bass cat Pantera II that has a Mercury black Max 200. Lately the boat will not Go over 2000 RPM's. The shop did compression numbers and they all looked good. They replaced the statter (I think that's what's it's called) And said he was good to go

Well the boat is doing the EXACT same thing. This all start ed when the shop Convinced him that he had the wrong prop on and sold him a new one. They sold him a 4 glad 24 pitch no name brad prop could that be the problem?

Any ideas?sorry I do not have a serial number.

[JOE54]

still got old prop??????? put it back on

[OnTRAK]

A bad stator can often take out the switch boxes too. It is not uncommon for old switch boxes to fail soon after the replacement of the stator. Mercury recommends replacing the switch boxes along with the replacement of the stator. The switch boxes should be tested with a DVA meter. It gets expensive, doesn't it?

[Tim W]

still got old prop??????? put it back on

Yea he does. I don't think a prop will cost an engine 4k RPMs. He's gonna put the old one back on.

OnTRAKn,

What is a switch box?

[OnTRAK]

There are 2 switchboxes (sometimes referred to as "powerpacks") located on the starboard side of the engine block. They store and discharge AC voltage from the stator and trigger at the correct time to the ignition coils. The ignition coils in turn multiply this voltage to a value high enough to fire the spark plugs. One switchbox is for cylinders 1,3,&5 and the other for cylinders 2,4, & 6. If one box is bad, your engine will perform bad. Also if only one is bad, both should be replaced because the other isn't far behind. A simple test, which is one of the first things you should do, is to check for spark at each of the plugs to make sure all 6 are firing. You can also swap the wiring from one box to the other, and if the nonfiring cylinders move from one side of the engine to the other, it is probably a bad switchbox.

[JOE54]

check for spark on all 6 cyl, shurely the shop checked the voltage at coils when they replaced stator, your right it shouldn't cost 4000 rpm,cant ever tell these days though,seen a guy bring a boat to shop 3 times didn't know to take transom bar off

[Tim W]

Thanks guys I told he to have the shop check yalls suggestions

[JOE54]