removing exhaust cover and all then pieces underneath??

[bob johnson]

1988 70 hp. I decided since i am doing so much work sandblasting and painting every pieces of this motor housing and lower unit before i put her back together. as well as replacing every seal and gasket..I figure I will take the head off the power head just to look around....since it is just sitting on the bench.

the carbs are rebuilt and waiting...

will I broke 4 head bolts!!!!!

but I still got it off...rough!

the top of the lower piston and inside of the flat portion of that cylinders head was impregnated with debris...metalic!!! a lot of pock marking...

so something let go or got in there..

the compression was good in all cylinders..

the power had been off previously in its life... so there has been work done in its history...

I need to figure if i lost a piston ring...and or what else could have the shrapnel come from?

so i am thinking of taking the exhaust covers off to take a look sideways at the piston and rings.

but the schematic off all the layers under the cover is daunting...

do they come off easily or traditionally hard??

the cylinder walls are not scored.... not beyond normal use..there is still a lot of cross hatch!!

they look very good.....no stratches that are deeper than the cross hatch finnish!!!!!!!!

let me know about the difficulty of removing the exhuast cover.....


PS: the shrapnel embedded in the aluminum head was magnetic!!

double PS: the piston has a bunch of numbers and one set is .040

does that mean .04 oversize? the bore is 3.228"

thanks

bob

 

[tx1961whaler]

Re: removing exhaust cover and all then pieces underneath??

If you broke 4 head bolts off, then you may break off 10 exhaust bolts.

 

[bob johnson]

Re: removing exhaust cover and all then pieces underneath??

the exhaust cover bolts all came easy!!! very little torque...

the OMC manual had no picture of its dissasembly, but the SELOC manual showed a layering of about 4 levels 2 being gaskets and one the cover and there was an INNER exhaust housing...

I was thinking I would be able to look into a port of the cylinder.

no dice!!

the cover is alone ont his model there is no inner...and taking the cover off only reveals the water jacket area that keep the motor cool to the touch and supplies the head!! cant see anything!!

I think this motor is going to have to be taken completely apart.

the pistons while stamped .04 seem to be standard, while the bore seems to be .040 oversize..

the pistol stick out above the block about .030" and i can measure its OD...3.188

which seems to be standard

the piston can be pushed to either side in the bore!!!

what a mess..

looks like it is going to be a longer term project thatn expected.

bob