Merc 200 hole in piston

[JoshKeller]

Edit double post

[EuropeanAM]

That's some really screwy verbiage in that manual. It tells you to set the float "drop" (and then goes on to say that's the only adjustment made). Sorry but that's just wrong.

Float LEVEL is the only adjustment. Normally falls about 1/16" BELOW the top of the bowl as I recall (not ABOVE the bowl).

[JoshKeller]

That's some really screwy verbiage in that manual. It tells you to set the float "drop" (and then goes on to say that's the only adjustment made). Sorry but that's just wrong.

Float LEVEL is the only adjustment. Normally falls about 1/16" BELOW the top of the bowl as I recall (not ABOVE the bowl).

Could very well explain my sluggish hole shot if the bowls are overfilling and flooding out at lower rpm?

[EuropeanAM]

Drowning in fuel will certainly make it run poorly!

[JOE54]

guarantee if you set them above bowl as said above it will be way too rich

[JoshKeller]

I'm also assuming this is bad? Would that happen to be one of the charging coils?




And for reference, I should set the float level to ever so slightly under level?

[EuropeanAM]

You can see charging coils in the image above, not exactly clear what you're referencing to "look" at in the image, however.

Try setting the float 1/16" below the bowl surface... I'd pull up an OEM manual and look up that section but I don't have any of the archived ones here.

[JoshKeller]

You can see charging coils in the image above, not exactly clear what you're referencing to "look" at in the image, however.

Try setting the float 1/16" below the bowl surface... I'd pull up an OEM manual and look up that section but I don't have any of the archived ones here.

the coil facing the camera is completely corroded. It appears to be much deeper than surface rust - wondering if that could explain blowing a few rectifiers and the tach being erratic.

[EuropeanAM]

In and of itself- no. If you are careful, you can brush that rusty corrosion (at least some of it) from the lamination plate. Be careful not to compromise the windings, however.

[JoshKeller]

Triple checked all connections and cleaned them all and the tach now works until it gets to 2000 rpm then it cuts out immediately to 0. Battery is charging. Stator output is 8v ac in both leads at 1000 - 3000 rpm in my test tank. Any suggestions?

[EuropeanAM]

Is that stator output reading with the regulator connected (or disconnected)? Reading BETWEEN the two yellow leads?

[JoshKeller]

Rectifier connected - no regulator. Each yellow lead to ground seperate. Should I do reading together?

[EuropeanAM]

That's an AC current winding in the stator- you must read between the two yellow leads to determine resistance, or to determine output (in AC Volts).

Rectifier converts to DC.

[JoshKeller]

That's an AC current winding in the stator- you must read between the two yellow leads to determine resistance, or to determine output (in AC Volts).

Rectifier converts to DC.

Got that figured out - had a bad tach. As for temps, what should the heads be running after a long idle period? I used my infrared gun and the starboard side was 165 average over the 3 cyl and the port 160. Seems a bit high with 143 degree thermostats

[EuropeanAM]

Were you reading dead in the center of the thermosat cover? That's really the only place you can get a reasonably accurate temp reading on this engine model (leached combustion temps at many points on the heads will give inaccurate readings).

In general, at idle you would expect to see 143 degrees (+/- 15 degrees max) F.

[JoshKeller]

Were you reading dead in the center of the thermosat cover? That's really the only place you can get a reasonably accurate temp reading on this engine model (leached combustion temps at many points on the heads will give inaccurate readings).

In general, at idle you would expect to see 143 degrees (+/- 15 degrees max) F.

No, I was taking readings all over the head - specifically each cylinder area. The thermostat cover reads between 135 - 140 every time I've checked it.

Is it advised to run a temperature gauge off the port head, or get a buzzer sensor installed or just trust the water pressure gauge and the starboard side alarm sensor?

[leonreno]

Read this thread about my motor, same basic concern I had but not really an issue.
http://www.bbcboards.net/showthread....d+temp+leached

[EuropeanAM]

Water pressure and STB side overheat sensor (which should be attached to the warning horn).

You can leave the gauge in place, just know it's not accurate (and may lead you chasing ghosts).

[JoshKeller]

Water pressure and STB side overheat sensor (which should be attached to the warning horn).

You can leave the gauge in place, just know it's not accurate (and may lead you chasing ghosts).

No temp gauge currently in the boat. My main concern was if the port side thermostat stuck and there was no alarm system in place for that head. The starboard side is present and functioning if I ground out the wire coming from the switch sensor in the starboard side head.

[EuropeanAM]

Keep in mind- thermostats really only control water flow at IDLE (once you begin to plane off, the poppet valve opens allowing a straight-through flow of water/coolant). After the poppet opens... the thermostats are basically just along for the ride.