pulled powerhead today - where does crank seal go?

Hi all - so pulled my powerhead today on my 90 mariner 60hp.. the whole drive shaft was covered in black soot.. and the inside of the "leg"as well, esp near the top - it was crudded on there.. I also had oily nasty stuff getting coughed up thru the right top mount (rubber was missing) spraying black spots everywhere..


The manual was a bit vague about what bolts to undo - either way.. see the pic.. did i undo the correct bolts or must i remove the plate still attached?

I basically destroyed the adapted plate gasket - i can see the crank nose inside there, but do I also have to remove the exhaust plate to change the seal?

this is the view of the exhaust tube - the crank is inside the hole on the right.. is that where the seal is? and did I take the wrong section apart?



Also - anyone know what thread the powerhead bolts are? I literally had to chisel all mine off - except for two.. luckily no damage to the studded threads - im def going s/s on these!

Once you pull the bolts that hold the tuner plate to the block and remove the tuner plate, you'll have access to the lower bearing cap and the crankshaft seals that are pressed into the cap.

You should be able to find any hardware you need here, just look up parts per your serial number.

Typically those powerhead studs are fine-threaded.

HTH......ed

thanks ed - havent been able to trace my serial down, but so far i think its a 1990 belgian made. 9615874[h=2][/h]To remove the palte, is there anything I need to remove on the gear shaft side? I can only see the bolts on the rear of the motor in the pic above.. is that ill I have to remove to get the plate off?

Also - Im going to make the gaskets from gaskets material the same thickness if i cant source them here.. should I paint the gasket with anything (if homemade)? surely they will seal just fine? (oil resistant paper type) -

thanks for your knowledge! really help - first time im doing this.. after battling for months i finally came to the result my crank seals are shot - whole inside was a mess and gases lowing out the missing top/right mount hole (rubber was missing)..

As I recall, it's only the back bolts that hold the tuner plate to the block. The long studs provide the clamping force for the entire "sandwich".

If you have to make the gaskets yourself, you might want to use a gasket dressing such as OMC Perfect seal or Permatex #3 aviation-type.

Don't use RTV-type sealers on that joint. If that's all you have available, don't use the Ultra Copper. Red Hi-temp or Ultra Grey will work if you use a very thin coating. Otherwise the stuff will squeeze out and cure, where the excess may break-off and get in critical water passages.

The Merc gaskets are made of some sort of fibrous material that is no doubt stronger than your standard gasket paper, but if that's all you can get over there, you gotta use what you've got!

G'luck with the repairs.........ed

hi Ed - tx a mil, peace of mind for sure. was worried id be banging away and murphys law i crack sth! great - yes i do have permatex ultra actually, after using it in the states I hunted it down, excellent stuff - and i do use it VERY sparingly.. just a very light skin. What about shellac? that brown sticky stuff, ive had wonderful results on motorbike crank cases with that.. and its super cheap.. getting a quote from the mariner dealer tomorrow but I just know its gonna be expensive as goats cheese!

only to seal the exhaust plate so dont thing there much to block there.. if anything itll get blown out i hope after i fix my leaking crank seals!

ok so finally got the seal retainer out - man what a MISSION! broke a small piece of it off and cracked another part - 2 nuts broke off, had to weld bolt on and remove with impact driver -

anyway - got the seals out. hopefully no more broken bolts anymore.