MerCruiser 305 Alpha 1 2006 model not exhausting water w/new impeller in foot

[NoRefunds]

Hello everyone I'm new here and have searched the forum to no availability to my exact issue. Earlier in the week I hooked the muffs up that I have been using since I bought the boat new in 2006 just to run it to make sure we were ready to go for this season. It wasn't exhausting any water out through the through hull exhaust ports in the transom like it normally does, in fact the only thing that came out was a couple drops of water and some black soot (picture attached) - the engine itself is operating as it should. After googling around and searching the forums I quickly came to the conclusion that the impeller is likely the culprit since I didn't have any issues in the season before. So I went to the MerCruiser dealer and bought the parts I needed and changed them out last night. I noticed when I pulled everything apart that the impeller and associated parts had very minimal wear but I continued to change them and re install everything as a preventive maintenance procedure since I already had it apart. Nothing changed once I reassembled everything. I tried adjusting the trim as well as fast idling the boat but it didn't change anything even though last season and the seasons before water would come out of the exhaust regardless what position the trim was at or idle.

So now I'm thinking there is some sort of blockage somewhere so I'm looking for tips on how to flush the system as well as any other suggestions.

Thank all of you in advanced!

 

[Bt Doctur]

Was it winterized properly and is the water staying in the bilge

If everything was left drained it MIGHT take 30 seconds to show out the exaust

 

[NoRefunds]

Hello yes it was. There is no water in the bilge and I had it running (keeping an eye on the temperature gauge) for at least 7 minutes.

 

[alldodge]

Don't know if you have the 7 point or 3 point drain system, nor your motor serial number, but going with 7 point until I hear otherwise. Look at the link below at item 13, this is a check valve. Pull the hose off the thermostat housing leading from it, connect the muffs and start the motor. If you get no water start there

http://www.mercruiserparts.com/bam/subassembly/31852/12840/210

 

[NoRefunds]

Don't know if you have the 7 point or 3 point drain system, nor your motor serial number, but going with 7 point until I hear otherwise. Look at the link below at item 13, this is a check valve. Pull the hose off the thermostat housing leading from it, connect the muffs and start the motor. If you get no water start there

http://www.mercruiserparts.com/bam/subassembly/31852/12840/210

Hello I have the serial number for the engine. Here it is "0W651033" 265 HP. Does that confirm it is a 7 point drain system?

Thanks.

 

[alldodge]

It helps with providing the motor but not the kind of cooling.

The 7 point is like in the link above, the 3 point has one of these down low in front of the motor on the port side

 

[Bt Doctur]

Hello yes it was. There is no water in the bilge and I had it running (keeping an eye on the temperature gauge) for at least 7 minutes.

Just a couple of things wrong, If the temp gauge was reading no temp it was because of no water.At 5 minutes with no water the rubber couplings should start to smoke and the manifolds and risers will burn your hands.
Do you have enough water pressure on the muffs and is any water visable from anywhere else
Worst case is to pull the drive and insert a hose (from a washing machine cut in half) into the water inlet
to help isolate the problem

 

[NoRefunds]

It helps with providing the motor but not the kind of cooling.

The 7 point is like in the link above, the 3 point has one of these down low in front of the motor on the port side

Okay I will look into this tonight and get back to you.

 

[NoRefunds]

Just a couple of things wrong, If the temp gauge was reading no temp it was because of no water.At 5 minutes with no water the rubber couplings should start to smoke and the manifolds and risers will burn your hands.
Do you have enough water pressure on the muffs and is any water visable from anywhere else
Worst case is to pull the drive and insert a hose (from a washing machine cut in half) into the water inlet
to help isolate the problem

Well it was reading a temp because we were watching it so that it wouldn't over heat and we just shut it down once it got to its normal operating temp (right at 175*). So no damage was done in that aspect. Everything was cool. We had the hood off and seats removed so the engine could breath and so we could see if there was any leaks or anything that just didn't look normal.

EDIT: The boat was receiving the same water pressure as it always has and there is no water visable anywhere else. Everything stayed pretty cool even to the touch after running for 5-7 minutes the weather was overcast around 80* in SW Louisiana.

 

[Bt Doctur]

If your putting water in the motor and seeing a temp reading and the manifolds and risers are cool to the touch then the water has to be exiting someplace and not disappearing.
Can you confirm water in the block and manifolds by removing a drain plug? If not the drive is not sending the water to the motor

 

[NoRefunds]

If your putting water in the motor and seeing a temp reading and the manifolds and risers are cool to the touch then the water has to be exiting someplace and not disappearing.
Can you confirm water in the block and manifolds by removing a drain plug? If not the drive is not sending the water to the motor

Okay I will look at that tonight. Is it possible the thermostat isn't opening allowing the sea water to circulate out and is then just falling back out of the inlet holes on the foot?

 

[Rick Stephens]

Okay I will look at that tonight. Is it possible the thermostat isn't opening allowing the sea water to circulate out and is then just falling back out of the inlet holes on the foot?

probably not.

As mentioned before, pull the inlet hose off the thermostat , fire it off for a minute, and find out if water is making it up to the engine from the outdrive pump.

 

[Bt Doctur]

If you have somewhat normal water pressure from the house try this.
Turn water on enough to see water escaping from the muffs,have someone start the motor, 95% should immediatly disappear. If there is no change in the "splash" the pump is not pumping

 

[NoRefunds]

probably not.

As mentioned before, pull the inlet hose off the thermostat , fire it off for a minute, and find out if water is making it up to the engine from the outdrive pump.

Okay we are going to try this within the next few hours

 

[NoRefunds]

probably not.

As mentioned before, pull the inlet hose off the thermostat , fire it off for a minute, and find out if water is making it up to the engine from the outdrive pump.

ahh true. Okay I'll take a look at this idea as well. Good idea.

 

[Fun Times]

If possible, try posting a video of both sides of the outside transom assembly, the propeller and the flushing muffs while the engine is running. Let's see your initial engine startup of the flushing muffs, your idle speed and slightly rev the engine up to 1300 RPM which is the proper RPM to run the engine on the garden hose in neutral gear. Also be sure the flushing muffs are hugging the lower gear housing super tight. If the flusher is loose-fitting at all then you won't get the needed water to the engine or out the exhaust ports.

 

[NoRefunds]

If possible, try posting a video of both sides of the outside transom assembly, the propeller and the flushing muffs while the engine is running. Let's see your initial engine startup of the flushing muffs, your idle speed and slightly rev the engine up to 1300 RPM which is the proper RPM to run the engine on the garden hose in neutral gear. Also be sure the flushing muffs are hugging the lower gear housing super tight. If the flusher is loose-fitting at all then you won't get the needed water to the engine or out the exhaust ports.

Well the only thing is these muffs are the same muffs I have been using for years and honestly since I bought the boat new. They have never given me a problem.

I have a stupid question. The water pump on the front of the engine... Does that water pump circulate raw water through the engine? What are the blades made of? Rubber? Stainless?

After looking at past comments from AllDodge I was able to identify my cooling system. It is Standard 3 point drain.

 

[Bondo]

I have a stupid question. The water pump on the front of the engine... Does that water pump circulate raw water through the engine? What are the blades made of? Rubber? Stainless?

Ayuh,.... Usually bronze or cast iron,.....

Even without the circulatin' water pump, the impeller pump will move enough water that it is exhausted out the exhaust,....

As noted above, if there's water goin' into the system, it's Gotta be comin' out somewhere,.....

 

[thumpar]

Even if the thermostat was not opening the water would go out the exhaust. Any water the block does not need (thermostat controlled) goes straight out the exhaust. If the pulling the hose off the thermostat test fails you can pull the drive off and shove the hose in the water inlet on the bellhousing.

 

[alldodge]

Seems these days more issue show up with the 3 point drains. Unless your water pressure dropped from last year, or the water faucet was not fully opened, as others mentioned the muffs are leaking more then normal or there is a blockage in your cooling system.

BTW - appears you have an alpha drive, but do you have the belt driven pump, doubt it but just checking. You have a check valve (item 2) in pic. The water distribution housing below has a drain plug on it. Suggest connect muffs, removing the drain plug and start the motor, water should come flowing out fast. If that works, reinstall plug and retry with the one at the thermostat housing