1975 9.9 Seahorse Peehole Not Peeing

[flyingscott]

OK, this may be right that it does not improve the cooling as it is probably a different circuit from the exhaust. How about this? If you steer standing as I do with a long tiller and your up in the middle of a 12 ft Jon boat, going near 30 nph, in 4 to 6 inches of water you sure can see that bigger flow of water out of the pee hole. This is fact. Another Northern "bush trick" is to put a brass barb fuel tube connectorat the end of the plastic bigger pee hole tube. Then if you get dirt or with a larger jet motor outboard, tiny sand and gravel, in the tube, it will collect where that brass barb is and just remove the barb and reinsert to clear debris out of the pee tube/hole and you won't need to stick wires and weedwhacker plastic strings up the pee hole anymore. Then remove all the nutural safety switch gizmo and the red plastic throttle/starter cam BS and you are on the way to having a fool proof machine.

Since the peehole is before the water enters the motor. Any extra water you send out the pee hole by increasing it's orifice size, you are actually putting less water through the motor. You can also lower the water pressure in the motor and if you have the thermostat with the pressure spring. You may not build up enough pressure to push the thermostat open.

 

[oldboat1]

The thru prop exhaust is a bit more efficient with a converging ring in place. If yours is missing, you might purchase and install a replacement.

 

[racerone]

Are we sure that the converging ring is more efficient ?-------If it was then all props would have that feature.

 

[oldboat1]

Yeah, believe it was marketed that way (may assist in drawing exhaust and debris away, or at least that's been my understanding). If it works that way, it might assist in clearing away some of the OP's collection of nasties.

 

[thatone123]

FS, sounds logical though I have never had this problem. Most of the problems sucking up mud and weeds seem related to the small pee hole orifice clogging and causing a backwash of debris clogging that rubber hose. I have had small weeds totally clog the water pump at the entry junction where the water comes into the impeller housing and stop all cooling and stop the motor from overheating. Maybe the cold water we run in here helps, but since there is a thermostat I guess? it would make no difference.

 

[flyingscott]

If.you are sucking up weeds maybe you need to look at a mud motor. I have run with and without converging rings never noticed a difference. Some people seem to think the lower unit on the 9.9/15 hp is to big. It is a quality well built unit that works extremely well.

 

[racerone]

I agree for a 9.9 / 15 hp gearcase it rates #1 in my book.----The 93 and newer units were improved with 2 bearings and a longer bearing surface on the pinion.

 

[OptsyEagle]

As I’m getting ready to change the impeller, I noticed milky oil-like liquid dripping from behind the prop and down the lower unit. Anyone know if this needs a gasket replacement?

That is normal. It is the improperly burnt fuel dripping down your exhaust cavity. It tends to come about more when you are running a 2 stroke motor in neutral, without a load, like when you have it in a barrel. A 2 stroke loves a full boat at wide open throttle. Running in neutral or trolling will not hurt it, but it does not convert its fuel to power, as well.

 

[racerone]

Some of the incoming air / fuel mixture goes into the cylinder and right out the exhaust ports.-----It is 100% wasted.----Not sure why you would say ---" improperly burnt "-------This wasted fuel does even see any spark !

 

[OptsyEagle]

Some of the incoming air / fuel mixture goes into the cylinder and right out the exhaust ports.-----It is 100% wasted.----Not sure why you would say ---" improperly burnt "-------This wasted fuel does even see any spark !

Because properly burnt would mean that instead of it going right through the cylinder into the exhaust port it would actually get burnt and go through as exhaust and would not be wasted.

Let's not get held up on wording. His condition of dripping milky sludge is normal. That is the main point I am making.

 

[racerone]

Yes ----I know that the 2 stroke 9.9 / 15 hp models built from 1974 to 2007 are very good and sought after motors.----Perhaps look into where you would find a rotary valve.----Perhaps look into the reasons for a rotary valve too.

 

[racerone]

The newer 6 / 8 / 9.9 / 15 HP Mercury lower units are FLIMSY in my opinion.

 

[flyingscott]

Racerone is being nice the.Mercury lower units are junk. Bent prop shafts and broken driveshafts are all to common.

 

[flyingscott]

Powervalves and rotary valves have absolutely nothing to do with the fuel mix. Only the carb controls that.