OK....new to this forum. I am more of an antique tractor kind of guy but the wife and I bought a cottage on a lake in Michigan and we bought a 20' pontoon boat with a 40HP Nissan NS40C engine complete with controls. The motor starts well and we had witnessed the neighbor guy pulling kids around all summer long last year and, for $1,400, it didnt seems like such a bad deal.
So, Memorial Day weekend we dropped the boat in the water and drove for about 3 miles at slow speed getting a good view of the lake we live on for the first time. No problems......until we pulled the 9 year old kid in a tube. After about a mile at higher throttle, the motor bogged down and was running quite hot. I pointed the boat to the shore and beached the craft and pulled the motor the next day. The motor was quite hotn and was obvious it was overheated. At home in the garage, I did a compression check and found 95 and 93# of pressure in the cylinders (this is on a 20 year old compression tester) and the motor started and idled well.
I have pulled the lower unit and drained the oil....all dark oil and no milky coloring so I am going to venture a guess the seals are fine. I also noticed the pump housing was chipped from a former owner who tried to force the two units back together and the rubber grommet which seats on the water pump and seals the pump to the engine cooling water pipe was pretty much toast as well. After purchasing a new pump and seal kit and just before installing the new pump I decided to hook up a water hose directly to the water pipe leading to the engine above and when I turned the water pressure on at the spigot I noticed there was a leak of water coming from the water pipe higher up in the drive housing (low pressure and engine not running) and I was curious if this should leak there or only "spit" out the back of the unit.
This doesnt seem like it would be designed like that but, I am a newbie....so what do I know!
Big question is should this be addressed and pulled apart or is that leak normal? Also, i will be rebuilding the carb tomorrow as well. Any tricks or knowledge of dirty spots to clean would be welcome!
Thnaks!
So, Memorial Day weekend we dropped the boat in the water and drove for about 3 miles at slow speed getting a good view of the lake we live on for the first time. No problems......until we pulled the 9 year old kid in a tube. After about a mile at higher throttle, the motor bogged down and was running quite hot. I pointed the boat to the shore and beached the craft and pulled the motor the next day. The motor was quite hotn and was obvious it was overheated. At home in the garage, I did a compression check and found 95 and 93# of pressure in the cylinders (this is on a 20 year old compression tester) and the motor started and idled well.
I have pulled the lower unit and drained the oil....all dark oil and no milky coloring so I am going to venture a guess the seals are fine. I also noticed the pump housing was chipped from a former owner who tried to force the two units back together and the rubber grommet which seats on the water pump and seals the pump to the engine cooling water pipe was pretty much toast as well. After purchasing a new pump and seal kit and just before installing the new pump I decided to hook up a water hose directly to the water pipe leading to the engine above and when I turned the water pressure on at the spigot I noticed there was a leak of water coming from the water pipe higher up in the drive housing (low pressure and engine not running) and I was curious if this should leak there or only "spit" out the back of the unit.
This doesnt seem like it would be designed like that but, I am a newbie....so what do I know!
Big question is should this be addressed and pulled apart or is that leak normal? Also, i will be rebuilding the carb tomorrow as well. Any tricks or knowledge of dirty spots to clean would be welcome!
Thnaks!
