I put the new water pump impeller kit in and no water out the tell-tale. Assuming I did something wrong, I dropped the lower unit again and rechecked everything, double checked the direction of the impeller blades and put it all back together again, including that stupid shift rod screw that makes me move the starter out of the way. Still nothing out the tell-tale. Tried it in a drum. Hooked up the muffs and water flows freely thru the tell-tale with the motor off? Maybe I am getting too anxious, the power head is not hot to the touch after a full minute. If it is the thermostat, where is it? Looks like water is leaking from the joint where the lower meets the upper unit. Where do I go from here?
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1993 Johnson 48 HP cooling question
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Lil' Blue Rude
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Check to make sure the impeller key is right. The thermostat is in the top off the head right above the top spark plug. There should be a plastic plug about the size of a golf ball around that will unscrew. I took mine out when I got my motor but I run in summer here in SE Mo so it doesn't have any trouble warming up. Don't worry about the water from the mid section. There is a another pee hole that comes out right beside the exhaust in the midsection.
Bobg
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Most common problem is a plugged up pee hose. Check it with a piece of weed eater string to clear it., or remove the hose from it's outlet and see if you get water there. You could even run the engine for a short time with the thermostat cover off, but I'd start with the hose.
In smaller engine, folks do remove the thermostat sometimes with little effect, In the upper hp, 25 and above, it's not recommended, for the best efficiency in running. It's an operating temp thing.
In smaller engine, folks do remove the thermostat sometimes with little effect, In the upper hp, 25 and above, it's not recommended, for the best efficiency in running. It's an operating temp thing.
Lil' Blue Rude
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Like I say I run in 90* weather so I don't have any problem getting to operating temp with my 40hp. That and I'm running around 160psi compresion on both cylinders so there's some added heat. :mrgreen:
OK, great help as usual. I thought the same thing about the impeller key. When I went into it the second time I watched that key very closely, followed the manual diagrams and all that. The manual says to position the impeller blades as they would be when the driveshaft rotates clockwise when viewed from above. Anyway when the pump housing was back together, I looked down thru the hole on top. I guess you would call that the water outlet where the water is pumped up into the motor. I turned the driveshaft clockwise and I could see part of the impeller blades as they rotated around. So I assumed the key and the impeller were correct, maybe bad assumption.
Another possibility is that the rubber nipple that fits on top of that water outlet was folded over when I put the lower unit back on the motor. The old one was folded over about halfway when I found it.
Its really hard to see if that fits correctly when the lower unit is reinstalled.
But, what is this about testing it in gear? Does it have to be in gear for the tell-tale to pump water out?
How long before the thermostat would open?
I did try fishing a dowel up thru the pipe where the nipple above meets the upper unit. I did get a small amount of chewed up styrofoam out. But doesn't forcing water thru from the muffs mean the path is clear from the pump to the tell-tale?
Apologies for ranting on and on but this one has me puzzled. Thanks again for the great help.
Another possibility is that the rubber nipple that fits on top of that water outlet was folded over when I put the lower unit back on the motor. The old one was folded over about halfway when I found it.
Its really hard to see if that fits correctly when the lower unit is reinstalled.
But, what is this about testing it in gear? Does it have to be in gear for the tell-tale to pump water out?
How long before the thermostat would open?
I did try fishing a dowel up thru the pipe where the nipple above meets the upper unit. I did get a small amount of chewed up styrofoam out. But doesn't forcing water thru from the muffs mean the path is clear from the pump to the tell-tale?
Apologies for ranting on and on but this one has me puzzled. Thanks again for the great help.
Yeah I forgot you need to mate up the rubber outlet housing but it sounds like you did that.
Sounds like everything is together right.
IMHO it doesn't matter which way the impeller fins are facing. They might spin clockwise in forward gear but they spin counterclockwise in reverse so who cares which way they go in since they will right themselves whichever way their spinning.
I've had issues with outboards not pumping water correctly and when I would put in gear and rev it up some a lot of times that will get the water to flow. I've also had issues with muffs not sealing well enough to get water flowing.
I haven't looked at a t-stat in a long time but I think they are suppose to have a hole(s) in them that allows water to flow through regardless if their open or not. You did say water shoots through the pee hole with the muffs so water is getting through.
I'm pretty sure if you take your boat to the lake and drop it in the water your outboard will be pumping water since that's been the solution for me the few times i've dealt with this problem.
Sounds like everything is together right.
IMHO it doesn't matter which way the impeller fins are facing. They might spin clockwise in forward gear but they spin counterclockwise in reverse so who cares which way they go in since they will right themselves whichever way their spinning.
I've had issues with outboards not pumping water correctly and when I would put in gear and rev it up some a lot of times that will get the water to flow. I've also had issues with muffs not sealing well enough to get water flowing.
I haven't looked at a t-stat in a long time but I think they are suppose to have a hole(s) in them that allows water to flow through regardless if their open or not. You did say water shoots through the pee hole with the muffs so water is getting through.
I'm pretty sure if you take your boat to the lake and drop it in the water your outboard will be pumping water since that's been the solution for me the few times i've dealt with this problem.
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The engine should pump out of the indicator hose regardless of the thermostat. The thermostat makes zero difference in the operation of the indicator. The indicator hose originates on the exhaust side cover, completely independant of the cylinder head and thermostat.
The thermostat should be run at all times. It is there to warm the engine to around 135 degrees at idle to give you the best idle quality, fuel atomization, and it helps bring the cylinder walls up to temp for normal running clearances. Running the engine minus the thermostat will only promote premature wear between piston and cylinder walls, definietly not a benefit. Once up on plane there is a pressure relief valve that opens and supplies the major volume of water to complete cooling. The thermostat alone was never designed to supply the needed volume of cooling water while on plane.
The waterpump only rotates in one direction, regardless of whether or not you are in forward or reverse. It is attached to the driveshaft which is driven by the crankshaft. The engine (powerhead) only runs in one direction. The propshaft is the only shaft that can reverse it's rotation.
Having not seen your waterpump when disassembled I can only suggest that you remember what the cup and lower plate looked like. If they were grooved then your new impeller may not be able to supply the needed water volume and pressure at idle or off idle RPM. Grooves will allow water to slip around the pump vanes quite easily. Grooved pump parts indicate the need for a complete water pump assembly, not just an impeller.
The thermostat should be run at all times. It is there to warm the engine to around 135 degrees at idle to give you the best idle quality, fuel atomization, and it helps bring the cylinder walls up to temp for normal running clearances. Running the engine minus the thermostat will only promote premature wear between piston and cylinder walls, definietly not a benefit. Once up on plane there is a pressure relief valve that opens and supplies the major volume of water to complete cooling. The thermostat alone was never designed to supply the needed volume of cooling water while on plane.
The waterpump only rotates in one direction, regardless of whether or not you are in forward or reverse. It is attached to the driveshaft which is driven by the crankshaft. The engine (powerhead) only runs in one direction. The propshaft is the only shaft that can reverse it's rotation.
Having not seen your waterpump when disassembled I can only suggest that you remember what the cup and lower plate looked like. If they were grooved then your new impeller may not be able to supply the needed water volume and pressure at idle or off idle RPM. Grooves will allow water to slip around the pump vanes quite easily. Grooved pump parts indicate the need for a complete water pump assembly, not just an impeller.
lckstckn2smknbrls
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I don't get much water out of the pisser unless the boats in the water.
Bobg
Well-known member
Whoopbass said:
The drive shaft ALWAYS spins clockwise, no matter what gear you put the lower unit in. It will have no effect on the impellor except to keep it turning in the direction of the drive shaft.
You've either not mated up your water pick up tube to the water pump or you've got a clog in the pisser hose. Check the easiest and most common problem first. The pisser hose.
A million thanks to all!!!!!!!!!!!!!!
I took the easiest way out since I am only a mile from a boat ramp.
Backed the trailer in, fired up and watched the water run out the tell-tale like no body's business!!
Forward Reverse - Neutral did not matter lots of water.
Thanks again
I took the easiest way out since I am only a mile from a boat ramp.
Backed the trailer in, fired up and watched the water run out the tell-tale like no body's business!!
Forward Reverse - Neutral did not matter lots of water.
Thanks again
Bobg
Well-known member
Way to go!!!
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