Hi all,
I'm somewhat familar with basic, auto mechanical repairs but totally new to outboards.
I"m working on a 92', 4 HP, two stroke Mariner (made in Japan-Yamaha likely) and can't get the power head to separate from its base on the driveshaft housing. The 6 bolts (from the bottom) all came out fine, I have tapped on it sideways with a block of wood & ball peen but it does not budge. It's not frozen to the driveshaft, as I have taken the lower unit off and the driveshaft came off with that just fine.
Engine has only been used in freshwater since I've owned it but I bought it used. The Seloc manual says to pry it off carefully straight up off the driveshaft, but since that is already out, can't I tap on it or apply force sideways ? Can I use a propane torch (like for soldering copper pipe) to apply heat at the joint and then pry or should I try twisting it off? I tried (briefly)tapping a small screwdriver and a wood chisel into the joint to break the seal but it is very soft aluminum and I don't want to damage the mating surfaces.
The engine overheated last fall due to water pump impeller failure and I read that I should also replace the powerhead gaskets, since they likely carbonized and may not seal properly. The paint is in fact blistered near this joint (one side only) and I figure the gasket is probably cooked. The cylinder head cover came off neatly with just a moderate tap. The piston moves freely and the cylinder walls look great with no scoring, so I'm really lucky.
Also, the manual says to remove the flywheel and its internal capacitor charging coil as part of removing the power head. Is that really necessary if I'm not planning on any repair to these and can't I just leave them (and the carb) in place? I have disconnected all linkages, wires and anything that would interfere with separating the head off the housing.
Would it do any harm to just leave this old gasket be? Or is water from the cooling system possibly going to bleed into the powerhead?
Any suggestions would be greatly appreciated!
Thanks
JP
I'm somewhat familar with basic, auto mechanical repairs but totally new to outboards.
I"m working on a 92', 4 HP, two stroke Mariner (made in Japan-Yamaha likely) and can't get the power head to separate from its base on the driveshaft housing. The 6 bolts (from the bottom) all came out fine, I have tapped on it sideways with a block of wood & ball peen but it does not budge. It's not frozen to the driveshaft, as I have taken the lower unit off and the driveshaft came off with that just fine.
Engine has only been used in freshwater since I've owned it but I bought it used. The Seloc manual says to pry it off carefully straight up off the driveshaft, but since that is already out, can't I tap on it or apply force sideways ? Can I use a propane torch (like for soldering copper pipe) to apply heat at the joint and then pry or should I try twisting it off? I tried (briefly)tapping a small screwdriver and a wood chisel into the joint to break the seal but it is very soft aluminum and I don't want to damage the mating surfaces.
The engine overheated last fall due to water pump impeller failure and I read that I should also replace the powerhead gaskets, since they likely carbonized and may not seal properly. The paint is in fact blistered near this joint (one side only) and I figure the gasket is probably cooked. The cylinder head cover came off neatly with just a moderate tap. The piston moves freely and the cylinder walls look great with no scoring, so I'm really lucky.
Also, the manual says to remove the flywheel and its internal capacitor charging coil as part of removing the power head. Is that really necessary if I'm not planning on any repair to these and can't I just leave them (and the carb) in place? I have disconnected all linkages, wires and anything that would interfere with separating the head off the housing.
Would it do any harm to just leave this old gasket be? Or is water from the cooling system possibly going to bleed into the powerhead?
Any suggestions would be greatly appreciated!
Thanks
JP
