1996 Mercury 4 Cylinder: No water from Pee hole even after new impeller

[wharfcreek]

I have 40 hp 4 Cylinder 1996 Merc on the back of my little 13 foot Blue Fin. This boat and motor have been amazing.....and I'd hate to see this be the beginning of the end for the little old Merc. The engine has been running fine......very reliable....and been given good maintenance. A week ago I was out fishing in the Chesapeake Bay with no problems. Brought the boat home, put it up on the lift, and there it sat until yesterday when I was going to head out and fish a bit again. However, as I started the engine, I noted no water coming from the pee hole. I gave it another minute or so.....including a few engine revs to see if some increased water pump RPMs would blast out any potential wasp nest activity. Nothing! So, figuring the impeller had shot craps, I paddled the boat to a ramp, pulled it, and replaced the impeller. It was worn, but not damaged or torn up in any way. Just a bit 'deformed'. Anyway......dropped the boat back in the water......started the engine....and still no water! So.....I'm stumped! I don't see a thermostat on this motor, and I can't find 'squat' on the engine on the internet. ANY help, suggestions, or tech info would be REALLY appreciated! Thanks in advance......and hope to get an answer soon! Safe boating........ WC

 

[TD_Maker]

Are you sure the motor is not actually peeing INSIDE the motor casing? Maybe the pee hole hose is disconnected inside the housing, or perhaps the hose is clogged. Try running a piece of wire (leader wire or something) into the pee hole fitting. See if that clears it. Sometimes a salt buildup will clog those things.

 

[wharfcreek]

Hey TD, thanks for responding. I tried the wire thing as part of checking for wasp intrusion. I've found that to be a problem here in the past....where the damn 'mud-dauber' wasps will build a nest in about anything 'protected' around the water. I recently took apart several boat lift motors......all 'dead' according to the boat lift shop. In removing the end-bells, I found the motors PACKED with old mud nests. I imagine that's what caused them to overheat and burn up. I've also had these wasps build nests up in the 'tell-tail' hole in other motors I've had......so that was my first place to look. I didn't see any sign of that being the problem....no mud remnants came crumbling out, nor any other signs of 'cloggage'....ie salt or other debris. And....hose was attached internally. I tried following that back to see if I could located a housing for a Thermostat....but it appeared that the hose just attached to the top of the block. And, I didn't see anything that appeared to be a 'typical' T-stat housing....thus the question as to whether the motor even has one or not. I read some place that some of Merc's I-4s did NOT have a thermostat.....but how true that is, I am not sure. So, just looking for some confirmation. Again, any help would be great. BTW....this was working fine a week ago.....so it's like the thing just 'quit'. No slow degradation of flow, no noise, and now no chance that pump impeller is part of the problem. I'm quite confident that part of this has been properly re-conditioned. So, it's somethin' else..... just what, I'm searching to find out. Thanks....... WC

 

[TD_Maker]

To me, it sounds like the impeller key may have slipped off during the replacement. If the shaft is just spinning inside of the impeller, you will not get any water. Just my 2 cents.

 

[zabortnick]

If you can blow air through it then its the impeller key like TD Maker said.

 

[wharfcreek]

Just a quick up-date: Problem solved! Turned out there was a 'clog' at the nipple end of the head where the pee-hole hose connects. Like I said, the hose was clear, as was the end where it discharges.....but the little nipple where the hose connects at the top of the cylinder head.....that was 'plugged' with some crud of some kind. I pulled the hose off.....and saw just a drip or two coming out.......so I stuck a small pick in there and the plug basically blew out. Now......all is good! I was really VERY confident that I didn't mess up the impeller install.......but good to confirm it by finding the problem elsewhere. But, even better to just have it all fixed and get back to fishing!! Thanks all!! Tom D.

 

[wharfcreek]

Hey TD, thanks for responding. I tried the wire thing as part of checking for wasp intrusion. I've found that to be a problem here in the past....where the damn 'mud-dauber' wasps will build a nest in about anything 'protected' around the water. I recently took apart several boat lift motors......all 'dead' according to the boat lift shop. In removing the end-bells, I found the motors PACKED with old mud nests. I imagine that's what caused them to overheat and burn up. I've also had these wasps build nests up in the 'tell-tail' hole in other motors I've had......so that was my first place to look. I didn't see any sign of that being the problem....no mud remnants came crumbling out, nor any other signs of 'cloggage'....ie salt or other debris. And....hose was attached internally. I tried following that back to see if I could located a housing for a Thermostat....but it appeared that the hose just attached to the top of the block. And, I didn't see anything that appeared to be a 'typical' T-stat housing....thus the question as to whether the motor even has one or not. I read some place that some of Merc's I-4s did NOT have a thermostat.....but how true that is, I am not sure. So, just looking for some confirmation. Again, any help would be great. BTW....this was working fine a week ago.....so it's like the thing just 'quit'. No slow degradation of flow, no noise, and now no chance that pump impeller is part of the problem. I'm quite confident that part of this has been properly re-conditioned. So, it's somethin' else..... just what, I'm searching to find out. Thanks....... WC