Thermostat or relief valve help

[Twista]

first of the pee stream is almost non existant on the starboard engine. these are DF175s. when hooked to flush port the port shoots way out but the other dribbles. went out the other day with a moderate load of 6 adults and supplies on my 253 Mako WA and almost immediately I got an alarm and the one engine went into a safe mode I guess as it did not have full power. I am going to try and blow any debris that might be lodged in the pisser hose, but if I need to dig deeper I am wondering what the next logical step is? thermostat or relief valve and am not sure if they can be accessed while the boat is in the water as I live on a canal here on long island, also the location ofr both items would be very helpful as the service manual doesn't really cover much and im sure you guys have more hands on experience that would be useful. thanx in advance to all who contribute....

[keakar]

step 1 is to replace the water pump impellers to restore water flow for cooling, if it still acts up after doing this, then and only then, do you start looking elsewhere for problems

[Twista]

im leaning away from pump failure as I see spurting from the pee hole and it increases slightly if I switch flush ports. the boat is in the water for the season and removal will require taking the boat out. I think its debris but if not im wondering if its the thermostat or pressure plug and if so where are they located, anyone else experience this phenomenon and care to chime in, thanx for your input though.

[Moonlighter]

If it is a blockage, every chance that it is

(a) chunk of the impeller given the overheat that occurred so quickly.
(b) if you have run thru a sandbar or mud then the water passages in the leg are likely to be chock full.

Both of these require the leg to be removed because the blockage is more likely to be there than anywhere else. The tell-tail is just that.

Thermostats can get stuck, but far less likely to happen than these things.

[Twista]

I live where it is very shallow at low tide and it is not uncommon to get caught in very shallow water, and yes there has been some mud exposure, if I did remove the leg as you call it, where would I flush? how would I clean her up so to speak? thanx for the quick response.

[Harper2]

im leaning away from pump failure as I see spurting from the pee hole and it increases slightly if I switch flush ports

I'm wondering about this comment. What do you mean if you switch flush ports? How exactly are you flushing?

[Twista]

the Suzuki had 2 flush ports one on the side and one at the the rear.. I switch the hose back and forth and I notice slight spurting is what I meant,

[Harper2]

That doesn't do much in the way of explaining what I asked for, exactly how you're flushing.......so let me rephrase....what is your procedure in flushing your engine? Are you running the engine while using one of those flush ports? That's what it sounds like to me, which is why I asked in the first place. You are not supposed to run your outboard while using those flush ports. You must use muffs on the water intake to flush while the engine is running. You risk damaging the engine (inadequate cooling) if you run using the upper flush ports. They are for use only with the engine off.

And in reference to your original post. You say the motor in question triggered an alarm, and went into safe mode, "you guess". Since you're looking at overheating as the reason for the alarm, did the overheat light come on with the alarm?

[Twista]

no, motor doesn't run when flushing they are off. and yes both the light and buzzer came on then there was a noticeable loss in power on the one engine. spent the day at tobay beach and later that evening it had full power again and we zoomed home where I flushed the engines while off. the one pees 7 feet out. the other just dribbles and spurts. they used to be identical.

[Harper2]

Okay, I'm glad to hear that you haven't been running the engines using those flush ports. I was not aware that the engine would pee when not running. So...... just a guess on my part here, but you might try using some muffs on it and flush it with the engine running. That is, after all, the preferred flushing method, according to your owners manual. The extra force of the water pump might help clean it out. Also run a flexible wire or heavy monofilament fishing line up into the pee hole to try and dislodge any obstruction. Since your motor seems fine now, you might have had a blockage temporarily that caused the overheat alarm, then it cleared itself out but still left debris in the pee tube.

[Twista]

update, took a compressor to the pee hole and she pees fine now, then I took it for a 30 minute ride and still peed like a champ identical to the other motor, halfway home I noticed it weaken then the alarm again. came home and blew air up the hole again, when I take the lowers of to do pumps this season where should I look to clear any obstruction>

[Harper2]

I'm now in full agreement with keakar. You have to pull the bottom unit and service your water pump. I'm sure you are needing a new impeller. The overheat alarm is one clue, and the concurrent weakened telltale stream confirms it. The mud that you say you encounter on occasion has worn the impeller to the point that it no longer pumps water efficiently. When you said that you were leaning away from pump failure because you had a strong stream when flushing, that's why I thought you were running the engine during flush. (Why would you eliminate the pump as a problem if you weren't even running the pump during the flush?)

So do that impeller replacement. While you're at it, do BOTH of your outboards. The other is sure to follow suit very soon.

[Twista]

still not quite understanding, no pee, then after blowing air up there peed like a champ, underway at 40mph peed just fine identical to the port engine, then a weakend stream but still peeing and then the alarm again, blew air in it again and then fired them up and peeing identical again. im thinking its something that gets lodged and then I blow it out of the way and then it lodges itself again. that's why I want to know where to look when I do drop them at the end of the season or in the beginning of next season. thanx for all the help.

[Harper2]

The tell tale stream is an indicator of a working water pump. The water that comes out has come directly from the pump without going through the engine's water jacket. Water goes directly from the pump, through the oil cooler and then out the pee tube. Clearing your pee tube, will not dislodge a water jacket blockage, if indeed you have such a blockage

You originally asked fot the next logical step. The next LOGICAL step is to pull your pump.