2001 90 hp 4 stroke problem

Hello, newbie here, but by what I have already read, seems you all might can help me.

My 90 hp Honda(while running) has recently started running a good amount of steaming hot water out of the back of motor where you can hook up to flush it. This started after I pulled the lower unit off to diagnose why the motor wasn't "peeing" as strong as it had before. The waterpump assembly looked to be in good condition, so I stuck it back together. Then this problem with the hot water started.

Just to be clear(as mud I guess I have (2) problems now. 1 - It was still moving/peeing water, and has not overheated, but just very little pressure(idle or revved-same pressure). 2 - Hot steaming water now coming out of 1/2" hook up at back of motor after reassembly. I usually like to fix my own things, such as replace a waterpump, but this might be a little much for me. Any help ya'll could give would be greatly appreciated with all the local repair shops being backed up for weeks!!!

P.S -I don't know if it helps, but the "peeing" does not get stronger whether you cover the larger hole or not.

Your thermostats might be corroded with salt.
suggest open it up and replace them to begin with.
do you flush with fresh water ?

It is probably good to check thermostats in any case.

The water is bypassing the relief valve and gasket (part #s 4 and 8 http://www.boats.net/parts/search/Honda/Outboard Engine/2001/BF90A1 LRTA /THERMOSTAT/parts.html)

They are probably blocked open by salt, debris, etc. When you flush the water goes into the port #9 through the hose in the dotted box below it. The pressure of the water opens the valve and lets the fresh water into the motor. When you turn the water off, the spring should push the valve into the relief valve gasket (grommet) and close it off.

You will have to disassemble and clean up. Most likely, you will need at least a new grommet and two of the #7 o ring seals.

If that is gunked up and you have not recently changed your thermostat, the thermostat probably looks as bad or worse.


Mike

Whoops! Just as I hit submit, I noticed that I was referring to the wrong bypass valve. The parts in the flusher are #'s 4, 8, and 19.

The one I first referred to is a bypass, which also gets gunked up. While you are at it, it you are finding a lot of salt buildup, you should clean that one also.

Sorry for the confusion.

Mike

Thanks so much guys. I'll look into this. Is this possibly tied to the lack of pressure from the waterpump also, or will this possibly just cure my hot water issue? I just still can't believe the impeller and housing looked so good when I took them apart. Just kinda expected it to be in bad shape.

Note - This is strickly a saltwater only boat, and I do flush with fresh after each outing. I'm assuming with never going through the thermostats before, it might just be time.

Hope you get it figured out. Does sound like possibly a thermostat issue. The salt is hard on our motors.

If the flushing bypass valve is stuck open, it will cut down the water pressure in the block and will also cut down the water indicator pressure.

If you want to do a quick test, find the hose that goes from the flush port to the bypass and take a needlenose pliers and pinch it off as the motor is running. That will stop the water from coming out the flush port and the water indicator pressure should increase.

Mike