Sea Water Pickup Problem

[nateo]

'86 mercruiser alpha one chevy 305

On muffs no water comes out exaust. Replaced outdrive impeller already. Have drive back on now unfortunately. I disconnected big hose on top of engine and on other side of power steering cooler. Ran garden hose and water came out other side of power steering cooler so I know that's not plugged up. I guess my question is what's in between power steering cooler and impeller that could easily get clogged up with sand or something?

 

[alldodge]

'86 mercruiser alpha one chevy 305

On muffs no water comes out exhaust. Replaced outdrive impeller already. Have drive back on now unfortunately. I disconnected big hose on top of engine and on other side of power steering cooler. Ran garden hose and water came out other side of power steering cooler so I know that's not plugged up. I guess my question is what's in between power steering cooler and impeller that could easily get clogged up with sand or something?

If you disconnected the hose and started the motor without having water going through the impeller, you burned up the impeller.

what's in between power steering cooler and impeller that could easily get clogged up

There is a fitting in the drive which can get clogged up. Check the hose connection going from the drive to the PS cooler

 

[nateo]

Never started motor. Do i need to pull drive off to check? Someone told me to pull drive off and run water through inlet. Dreading pulling drive off. I had a hard time putting it back on. Something is clogged up. Problems started after an encounter with sandy beach

 

[Bt Doctur]

Is there anything else we should know before trying to guess at an answer?
I did have one that blew off the hose at the gimbal housing.
shift into fwd and remove the drive.
insert a hose into the water inlet and report your findings

 

[Watermann]

You should pull the drive and use the garden hose in the inlet and see if anything gives or if it has a blockage. Also make sure the water pipe that attaches to the water pump housing is clear too. I hope you didn't run it and have an overheat after that sand got packed in there. If so then it could be even more problems like burned out flappers stopping up water flow on the exhaust side.

 

[nateo]

ok so when I had the drive on I stuck garden hose in water inlet hose aft of the power steering cooler. water did not come out of drive, just backed up. I removed drive and turned on hose in same position and water came out water inlet hole in bell housing. I stuck garden hose in water inlet hole of outdrive and it didn't see any water coming out of bottom of drive. Before I split apart outdrive (not looking forward to it) are these tests correct? Is it likely something in the drive that is plugged up?

 

[nateo]

I went ahead and split drive apart. Not seeing any obvious signs of blockage. If I blow out into the plastic tube in lower unit I'm getting at least air coming out the weep hole

 

[nateo]

There is a fitting in the drive which can get clogged up. Check the hose connection going from the drive to the PS cooler

Which fitting?

 

[UncleWillie]

Take the Top cap off the Drive.
If you have a Reserve Drive Oil Bottle on the engine, empty that first or you will have oil everywhere.
The water cooling jacket for the upper drive is under the rubber cap just behind the gear box.
Every last drop of water going to the engine flows through this passage.
If the jacket is full of sand it will block the flow.
Water flow into this area is from the bottom, and then out through a passageway on the Port Side, forward to the Gimbel housing.

Caution!!! If the jacket is full of sand, do not get any sand in the gears.
The rubber plug lifts out easily. Lift it gently like like it is a Bomb Detonator and never position it over the gears.
Duct Taping over the gears is highly recommended. Don't make things worse.

If it is full of sand, try getting it wet and suck it out with a Turkey Baster.

 

[nateo]

I'm almost ready to surrender. I had outdrive apart. I flipped upper upside down and poured water down copper water inlet tube. It flowed freely out the hole in the upper where it should. I took cap off water pump hosing and poured water down the hole, water flowed freely out the bottom of the lower unit as it should. Noticed water inlet plastic guide tube was deformed (from heat). Took to parts guy and he recommended replacing entire water pump housing (said sometimes they get warped when overheated). So I replaced entire water pump housing, impeller, and gaskets (followed parts diagram for this drive to make sure gaskets were put on correctly). Also replaced rubber gasket in upper where the copper tube slips into. Replaced all other rubber o-rings and gaskets necessary to put drive back on. removed water inlet hose from top of engine and started her up. No water ever came out of this hose. I left on for about 30 seconds or so, didn't want to overheat any thing. When I had the drive off I was able to pour water down this same hose and it came out of water inlet hole in bell housing so I know that pathway is free.

What am I missing here. Do I need to let it run longer and or put that hose back on or is there something else that could be the problem?

P.S. I do not have that compartment pictured above when I take the cap off, only the gears.

Please help, hoping to take her out this weekend. Thank you.

 

[Bt Doctur]

Are you USA located?
you have to isolate the problem first. remove the drive, insert a hose into the water inlet fitting, turn on the water. Water should exit the exaust even with the motor off.
If water exists the exaust, start and run the motor and report the engine temps.

 

[nateo]

Are you USA located?
you have to isolate the problem first. remove the drive, insert a hose into the water inlet fitting, turn on the water. Water should exit the exaust even with the motor off.
If water exists the exaust, start and run the motor and report the engine temps.

I can try that tomorrow but I have a suspicion that the water is not even making it inside the boat. Is it possible that the driveshaft is not spinning for some reason? I tried putting it into gear with engine running and it didn't make the usualy sound of going into gear and the propeller did not turn.

"as the propeller turns"

 

[Bt Doctur]

Stop guessing, do the tests and report back.you should nave noticed if the driveshaft was broken when you did the impeller.
ok, here try this. with the ENGINE OFF, SHIFT INTO FWD GEAR
stand on a blade of the prop trying to turn it CCW and have someone watch the shaft behind the engine.
shaft spins, engine dosent= bad coupler
shaft dosent spin and prop turns= broken shaft or melted gears in the upper unit.

 

[enginesilo]

No Title

You've been given good advice by everyone already. Lots of possibilities, but probably only 1 main problem going on. I would try to feed the water hose into the bell housing inlet area and see if the engine cools itself. This way you can quickly rule out if the issue is from the bell housing and into the engine somewhere, or definitely in the outdrive. This will help you get to the root of your problem quicker. If you aren't familiar, here is a picture of where to put your hose for the water inlet. This is an Alpha 1 gen 2, but I think the alpha 1 is nearly the same.

On my boat with an Alpha 1 Gen 2 my motor would run very hot on the hose, and would hardly push out any water from the exhaust at all. I also had no clue what it could be. I had a small oil leak in my outdrive so I was planning on taking it off anyhow. I was going to do the same test others have explained where you put your garden hose into the bell housing inlet with your outdrive disconnected but I found my problem beforehand. Mine ended up being my water pump impeller was shot. I had changed it the season before so I was almost certain that wasn't the problem, but it ended up being the issue. I did a water pump rebuild, reinstalled everything, and I can now stay on the garden hose all day long and run cool, with lots of water exiting the exhaust.

Hitting a sandbar and ingesting sand can very well be where your problem has stemmed from, so definitely keep chasing that to see where it leads you.

Another random possibility, could you have a slipped water pump impeller key? On the alpha 1 gen 2 there is a small key that holds the impeller onto the drive shaft which allows it to spin with the driveshaft. If that key slipped your impeller may not be spinning, or, it has been damaged and is doing a poor job of pushing water.

 

[Eric 3.7LX Alpha 1]

The full rebuild kit for the impeller was the way to go since that top plastic guide was melted.

If the drive is still off, I would also run the engine with the hose in the water inlet. Just so you can confirm the engine stays cool.

I don't know how much water pushes thru the water impeller in the drive while it's off, I bet not much. I know when I turn on the water to the muffs on mine, while the engine is off, water is spraying out of the muffs sides like there's a restriction... once the motor is started it's taking all of the water with very little side spray. This is normal my engine runs very cool on muffs or on the water. Maybe it's just the impeller not turning and blocking the opening.

Did you have an issue running hot?

 

[Fun Times]

I can try that tomorrow but I have a suspicion that the water is not even making it inside the boat. Is it possible that the driveshaft is not spinning for some reason? I tried putting it into gear with engine running and it didn't make the usually sound of going into gear and the propeller did not turn.

This potential issue needs to be confirmed and repaired if found correct before you continue to find a non water flow issue due to if your input shaft between the engine coupler and stern drive isn't turning then it's possible the driveshaft of the lower unit isn't turning as well which would give you no water flow to the engine. The test in post 13 may help find something wrong.
Keep in mind that the shifting to make the propeller turn is done inside the lower part of the lower gear housing....Under normal circumstances the impeller should always be turning while the engine is turning even if the prop isn't turning.

When you reinstalled the lower gear housing to the upper drive housing did you ensure item numbers 21 & 22 slid into each other? http://www.mercruiserparts.com/Show_...c=BELL+HOUSING

^^^, Also when you're R&Ring any part of the drive, You'll need and want to put the shifter into forward gear to avoid damage and to make installing the lower to the upper easier as it'll help give you a sense of direction of how it should all go together and to help confirm everything seems to be in working order before and during installation.

You should noticed item's 21 & 22 are pointing straight ahead (12 o'clock)(fore and aft) for drive removal and installation... When the two shift shafts are at 12 o'clock you should notice the propeller shaft will lockup when turning it counter clockwise. http://www.boatinfo.no/lib/mercruise...iser6.html#/30

Noticed water inlet plastic guide tube was deformed (from heat)... I also replaced rubber gasket in upper where the copper tube slips into. Replaced all other rubber O-rings and gaskets necessary to put drive back on.

Sounds like you replaced item number 3 but did you carefully remove and inspect item numbers 2 & 4? If the water pocket is damaged inside the upper drive housing due to heat or sand then it could be a water flow problem if the "shafts" are turning that is.
http://www.mercruiserparts.com/Show...br=80&bdesc=DRIVESHAFT+HOUSING+AND+DRIVESHAFT

Keep in mind this is an 1986 which is an older type alpha model drive...Sometimes referred to as an Pre-Alpha drive.

 

[nateo]

Thanks guys i have more things to check now. To answer a few of the questions. The little key is in there i spun the spline by hand with casin partialy open to make sure. When i start the boat the water keeps splasing out the mufs as though the drive is not sucking any water in.

 

[Bt Doctur]

Thanks guys i have more things to check now. To answer a few of the questions. The little key is in there i spun the spline by hand with casin partialy open to make sure. When i start the boat the water keeps splasing out the mufs as though the drive is not sucking any water in.

With the new impeller installed I find it impossible to turn the driveshaft by hand. For some reason I think your going to find the motor runs cool on a hose.Do the stand on the prop test and let us know what turns and what dosent.Then remove the drive and do the hose test and report your findings.
Are you in the usa?

 

[nateo]

things just went from bad to worse. When I start it up coupler spins but shaft does not. I put shifter in forward wot. Had someone spin propeller counter clockwise and the shaft inside boat spins but coupler does not. What goes bad in a coupler? Does motor need to come out to fix? Looks like there is a little bit of space between coupler and boat (maybe 6 inches)

 

[Bt Doctur]

the coupler is spun and the motor comes out to repair that part. Most failures are caused my miss-alignment from a collapsed rear bushing.
the rear housing comes off and the rear bushings replaced.If the front mounts are very rusty ,they should be replaced to allow easier adjusting.