pressure?

[JohnsonM50]

Im preping my hydro to run, its an OMC 25 with a Yamato 102 foot adapted below the waterpump. It has above the waterline exhaust and has been run alot before this happened.. I was unscrewing the foot drain plug and it was under pressure, maybe 20 or more psi. It had some sign of a little bit of water but ran good last time out and wasnt leaking at all, not a drop. Im thinking the waterpump would not hold such pressure stopped but could it have pushed water into the foot to be trapped behind the seal? Have any of you who race Yamatos ever seen a foot pressurize for any reason? :confused: I suspect the pump but wonder too if the gasket could let water in that might be trapped.

[sst45jefff]

Yes the water pump can push water past the seal into the gearcase. One of the symptoms is the gearcase being presurized.
Sound like you need to change the seals below the water pump.

[jeff55vDSH]

Im thinking the waterpump would not hold such pressure stopped but could it have pushed water into the foot to be trapped behind the seal?
What direction is the seal facing? The fix may be as simple as turning the seal around to face the other way. :)

[JohnsonM50]

What direction is the seal facing? The fix may be as simple as turning the seal around to face the other way. :)

Thanks Jeff, On these as stock OMC feet theres 2 seals back to back 1 down for oil the other up for water. They were in right but worn out. With the coupler about an inch below and 2 seasons on em I shoulda done them with the spring waterpump. :rolleyes: