9.9 sea horse overheats, water is comming out of pee hole

[poida]

Hi, great forum, have learn lots today but not exactly what i need
The motor is a 9.9 late 70's abused and undermaintained sea horse.
It overheated twice on full throttle and stopped/stalled/seized, not sure which, and let smoke out of its engine cover.
It has water comming out of its peehole at idle, and at full revs, although at no greater rate. Both times it went bang, the captain thought it had water comming out the hole but was probably looking ahead, not back at the motor.
I grabbed it thinking to strip and rebuild but after testing it started, ran and revved well. The water flow seems ok to me but i have no doubt that i will cook it a 3rd time if i try to rev it for a prolonged period. The water did get quite hot under full revs.
Should i try a water pump first or strip it assuming that internal damage may have occurred? Also does it have a thermostat?
Many thanks for any thoughts and suggestions

 

[tashasdaddy]

Re: 9.9 sea horse overheats, water is comming out of pee hole

model # of the motor so we know what you have. yes it has a tstat on the lower part of the cylinder head. i would put a tstat and water pump kit in it. also check your compression on both cylinders, could be a blown head gasket into the cooling system.

 

[freddyray21]

Re: 9.9 sea horse overheats, water is comming out of pee hole

fully agree with Tashasdaddy. The water pump in those changes the way it pumps at idle verses wide open. If it's bad or more if the housing is bad it can suck air at higher rpms and you loose water.

 

[BaitThrower]

Re: 9.9 sea horse overheats, water is comming out of pee hole

thermostat probably stuck closed or blocked.
Water passages could also be blocked up.

Pee hole stream only indicates water pump is working on that motor, doesnt indicate whether water is circulating around the head or not.

I'd pull the thermostat cover and cylinder head plate off and check it out, clean out the water passages while you have it off, install new head gasket and do compression check.

 

[poida]

Re: 9.9 sea horse overheats, water is comming out of pee hole

Thankyou for the replies
I am currently away for the next 5 weeks so can not provide the engine no.
It seems i should
Compression test, if good.
Replace water pump and thermostat, flush with garden hose while leg is in pieces. Remove cylinder plate cover and clean out the water passages.
Compression test, if bad.
Strip, rebuild with rings and gaskets, water pump and thermostat.
What should the compressions roughly be???

Baithrower, you mentioned the head gasket, do you mean the cylinder cover??? I presume that to renew the head gasket (cranckcase to head)would mean removing the engine and pretty much stripping it?

Another question, what would have caused the engine to stop. Seized or too hot for the coils

Thanks again guys

 

[F_R]

Re: 9.9 sea horse overheats, water is comming out of pee hole

Siezing from overheat is caused by the pistons expanding and closing up the clearance between them and the cylinders. Add to that, oil break-down from too hot. Bottom line often is damaged (scored) pistons and cooked gaskets that will leak in the future.

 

[tashasdaddy]

Re: 9.9 sea horse overheats, water is comming out of pee hole

on a 9.9 you would probably have to remove the head, as there is not much room to work.