alpha one no or very very little water exiting through prop or exhaust relief ports.

[Bass2mouth]

Hi guys I have been a long time follower and recently joined to ask some questions about my new this summer boat. First the boat is a 1978 sea ray SRV 220, the motor and drive are a bit more complicated. The mercury marine tag on my motor is serial # L033402. = 5.7L alpha one.= With the old style log manifolds and cooling system and A Rochester quadrajet carb.

The problem that I am having is that I have very restricted almost non existent water flow exiting the exhaust ports on the upper out drive, and the through prop. Im assuming that my problem is a result of this. The problem.

Boat starts idles and runs perfectly, but after on plane for 5 min it will begin to overheat, and continue to climb in temp until I pull back on the throttle to 800-1000 rpm and putt, or put it in neutral and idle, then it will cool down to normal temp, back up on plane or any rpm above 2000 and the circle starts over again. The boat will run at below 1400 rpm all day with no issues.

Boat is raw water cooled.

I have replaced the pump in the lower unit - complete kit. And still same thing.

The old impeller was missing all but 1 fin, I tracked down little bits and pieces in the therm housing, but not all of them.

What I have done/ observed
1. Removed the thermostat housing- no thermostat in the housing old owner must have removed it.
2. Removed line from raw water pump in lower unit just after the steering cooler- water flow is good, flows 10-14 inches vertical.
3.removed log style manifolds and risers- pressure tested water passage to 18psi with air and held for 10 min. no drop in pressure
4.Removed hoses from therm housing- plenty of water flow.
5. Poured 1G of anti freeze down the y pipe from wear the elbos would connect- slowly dripped out the exaust ports but not the through prop.
6. Tried to find the flappers/shutters in the y pipe. Could not see them. Did it ever have them? Are they stuck in their some wear?


Thanks for the help guys I really appreciate it. Is their any way to check if the y pipe is clogged with out pulling the engine? Any ideas? Any help would be great.
Thank for youre time.

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

engine serial # comes back as

0L033402 MERCRUISER 1998 5.7L 4311026LS ALPHA 5.0L/5.7L ALPHA/BRAVO GEN+

 

[NHGuy]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

You are correct to be trying to find blockages in the cooling flow.
There should be flaps in the top of the Y pipe. 1 on each side. If they are missing, the parts could have gone down the pipe and could easily be what's causing the exhaust restriction. I'm surprised you can get the boat to run at high rpms if liquid won't fly out the exhaust easily.
To avoid pulling the motor, get the drive off and look in the exhaust tube, maybe you MIGHT be able to do something, but it's not easy. That exhaust restriction in the Y pipe is the thing to go after first. There's probably stuff in the bottom of the Y pipe. You might think you can grab it with long needle nose pliers and try to pull it through the hole at the bottom but many have tried, none have succeeded. It's hard because you'd have to take off the bell housing and the flaps are metal so you'd have to bend em to pull them through the smaller exhaust outlet hole. I think the best thing is to try to break loose the pieces at the bottom so they are free, shove the pieces to the side a little and put a standard diameter vacuum hose adapted onto a high powered shop vac. Reach it down the Y pipe. Just make darn sure there is no gasoline smell, the electric shop vac motor will ignite any gas vapor in the air.
Once the exhaust down tube flows clearly, run the engine again. If it still gets hot there is the possibility that there are bits of impeller fins causing restrictions. Did I understand that you tested the water output before the thermostat housing? That's a good start. I believe on your drive you expect 2 gallons for each 30 seconds at 1000 rpm. If it still runs hot after the exhaust is clear do some more checking for impeller pieces. There can be bits in the hose from the bellhousing to the transom, and there can be some in the power steering cooler. Also the hose from the bellhousing to the transom plate has to have NO kinks in it. So inspect those things before dissassembling. If you end up removing the water pump, try to vac or blow out any cooling passages you can get to in the block and heads.
If that doesn't work PM me, I live on the MASS/NH border and I have the stuff to pull the motor, might be available to help you in the spring around March or April. I have crappy blood flow in my hands so I'm a cold weather wuss about working on metal boat parts when the temp is below 40.

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

You are correct to be trying to find blockages in the cooling flow.
There should be flaps in the top of the Y pipe. 1 on each side. If they are missing, the parts could have gone down the pipe and could easily be what's causing the exhaust restriction. I'm surprised you can get the boat to run at high rpms if liquid won't fly out the exhaust easily.
To avoid pulling the motor, get the drive off and look in the exhaust tube, maybe you MIGHT be able to do something, but it's not easy. That exhaust restriction in the Y pipe is the thing to go after first. There's probably stuff in the bottom of the Y pipe. You might think you can grab it with long needle nose pliers and try to pull it through the hole at the bottom but many have tried, none have succeeded. It's hard because you'd have to take off the bell housing and the flaps are metal so you'd have to bend em to pull them through the smaller exhaust outlet hole. I think the best thing is to try to break loose the pieces at the bottom so they are free, shove the pieces to the side a little and put a standard diameter vacuum hose adapted onto a high powered shop vac. Reach it down the Y pipe. Just make darn sure there is no gasoline smell, the electric shop vac motor will ignite any gas vapor in the air.
Once the exhaust down tube flows clearly, run the engine again. If it still gets hot there is the possibility that there are bits of impeller fins causing restrictions. Did I understand that you tested the water output before the thermostat housing? That's a good start. I believe on your drive you expect 2 gallons for each 30 seconds at 1000 rpm. If it still runs hot after the exhaust is clear do some more checking for impeller pieces. There can be bits in the hose from the bellhousing to the transom, and there can be some in the power steering cooler. Also the hose from the bellhousing to the transom plate has to have NO kinks in it. So inspect those things before dissassembling. If you end up removing the water pump, try to vac or blow out any cooling passages you can get to in the block and heads.
If that doesn't work PM me, I live on the MASS/NH border and I have the stuff to pull the motor, might be available to help you in the spring around March or April. I have crappy blood flow in my hands so I'm a cold weather wuss about working on metal boat parts when the temp is below 40.

its funny that you say that about the rpms. if im up on plane sometimes the engine will start to cut out " same sensation as if it was running out of gas ", if i pull back on the throttle fast enough it will recover, but if i do not it will stall and have to be restarted. its good to know that this could be related to the water flow, as i was starting to think it could be ignition coil getting to hot, plug wire grounding, or drop in fuel pressure.


if i have to remove the out drive to get or look for the pieces i might as well do the gimbals shift cable ect ect?

now would it be a bad idea, or could i damage anything, if i hook up a shop vac and run the vacuum hose down the y pipe as far as i can get it, then use my pressure washer variable pressure 1800psi-4800psi to shoot water into and up the exhaust releife ports in the transom plate while the vacuum is working from the other end? my thinking is that the pressure washer will force whatever may or may not be in the y pipe up into the vacuum the way they originally fell down?

does this sound ok? i would like to avoid pulling the drive and replacing all those parts if i don't absolutely have to.
if i do pull the drive i would be crazy to not replace and inspect worn items ect for preventative maintenance.

thank you for you're reply and generous offer, but im sure ill get it the cold doesn't bother me much.

 

[Bt Doctur]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

"I have replaced the pump in the lower unit - complete kit. And still same thing. "
Did this kit include the waterpump base? You could be sucking in hot exaust gases on plane.
Flow test by removing the drive and run on a hose inserted into the water inlet of the transom housing.

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

"I have replaced the pump in the lower unit - complete kit. And still same thing. "
Did this kit include the waterpump base? You could be sucking in hot exaust gases on plane.
Flow test by removing the drive and run on a hose inserted into the water inlet of the transom housing.

i cannot get the boat to over heat inless under heavy load, or up on plane for 5 min. im not sure what you mean by flow test by removing the drive and run on a hose inserted into the water inlet of the transom.

i am getting almost no water if any out of the thru prop and the exhaust releif ports.

if i disconect the water hose after the transome after the stering cooler and before the thermostat housing the water will fill a 5 g depot bucket in exactly 51 seconds at 1000 rpm. the problem i beleive is that im getting water in, i just cant get it out.

am i wrong? or miss understanding what you are telling me?
thank you for youre reply and time.

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

could the same thing be achieved by running the hose to the water inlet on the inside of the transom IE up stream of the steering cooler which is the first place the water goes once it goes through the transom, to avoid pulling the drive?

 

[mr300z87]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

Hi, I have. been following along and I was in a simalar situation as you a few years ago but with a 3.0l 4 cylinder. It was my first boat in 20 + years and had I had never touched an I/O before and was very intimidated. First let me say I have now been running an I/O for 3 years, pulling an outdrive is very easy 6 bolt (after putting control in forward) and should be part of your yearly maintenance. Once the drive is off you can run you hose into the water intake on the bell housing. My issue turned out to be clogged exhaust manifold and elbow it would run all day at low speed but over heat at high speed. Running in salt water does a number on the internals of exhaust system and I am told they only last 5 years or so. As stated above and make sure no blockage in the y pipe. Have you checked the circulation pump on the motor to make sure it is functioning properly. Good luck.

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

i am not very concerned about pulling the outdrive, or doing the every couple of years maintenance on the bellows gimble ect ect. i just dont want to pull it now in the winter and have it all apart all winter. i want to basically find out wear the blockage or issue is and fix it. if i have to order parts, and it turns out to be a bigger problem than im anticipating come spring i can put them on and be done with it. nothing worse than wasting several weeks of the fishing season waiting on parts ect ect.

i have not verified that the water pump on the motor is working, but i assumed it is based on the fact that it does not leak, is their a way to actually test it correctly? thank you for responding.

 

[UncleWillie]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

THIS may be of some Help.

 

[Bt Doctur]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

From the impeller, the water flow goes up the copper tube to the water pocket cover, loops around the upper unit to cool it and out the hole in the outdrive into the transom housing.A corroded hole thru the housing will prevent flow to the engine . A collpsed/split hose(internally) will restrict water trying to get into the engine. Pull the drive to verify how much flow there is with the motor off.Shoud be free flowing out the exaust even with the motor off. Its the only way to isolate it to the drive or the engine.
Next put the muffs on the drive and see if any leaks out, should be no leakage.If there is , split the unit to find out where.

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

From the impeller, the water flow goes up the copper tube to the water pocket cover, loops around the upper unit to cool it and out the hole in the outdrive into the transom housing.A corroded hole thru the housing will prevent flow to the engine . A collpsed/split hose(internally) will restrict water trying to get into the engine. Pull the drive to verify how much flow there is with the motor off.Shoud be free flowing out the exaust even with the motor off. Its the only way to isolate it to the drive or the engine.
Next put the muffs on the drive and see if any leaks out, should be no leakage.If there is , split the unit to find out where.

i have removed the water inlet hose going to the engine and i am getting plenty of water flow comming through the gimbal housing water tube, into the water inlet tube and up to the engine. " i will measure exactly again to double check how much water."

im not sure im understanding what youre saying, im sorry bt doctur, but if im getting plenty of water out of the water inlet hose on the end that attaches to the front of the engine wouldn't that rule out a fault in the out drive because it is after the out drive, coming from the out drive?

i feel that im getting water to the engine, pump on front of engine i cant say 100% or not if its working but assuming it is because the water goes through the block, up to the therm housing,to the rear of the exhaust manifolds, out the front of the manifolds, back into the bottom of the therm housing, then its supposed to flow from their up past the thermostat " my boat doesnt have a thermostat, previose owner removed it" to the exaust elbo, through the y pipe and out the exhaust releife ports and thru prop....


could no thermostat be causing some kind of lack of pressure causing water not to go out elbo?

i looked down the y pipes again today with flash light and bore scope, cannot find any trace or flappers/shutters.

bt doctur can i hook up a wet vac to the top of the y pipe, and a pressure washer to the exaust releife ports and try to blow the block or possible blockage up and have the vac suck them out? or will that plan cause damage to any parts?

thanks again for youre time. i appreciate it.

 

[haulnazz15]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

You definitely need a thermostat installed. The thermostat regulates the flow of water in the block, if the water isn't there long enough to absorb the heat, then you overheat because the water never does it's job. Typically a 160-degree thermostat is used on raw water cooled engines.

 

[NHGuy]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

Also while the drive is off blow out &/or backflush the hose from the thermostat housing to the bellhousing.
And definitely shoot some water in the Y pipe exit while it disconnected, just don't get any in the engine exhaust manifold. Like cover or tape over the exhaust, especially if the elbows are off.

 

[UncleWillie]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

You definitely need a thermostat installed. The thermostat regulates the flow of water in the block, if the water isn't there long enough to absorb the heat, then you overheat because the water never does it's job. Typically a 160-degree thermostat is used on raw water cooled engines.

Lack of a thermostat will cause a cold engine.
Over heating will never be caused by too much water moving too fast through the block.
Water properties do not include the qualty of "Lack of Patience".

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

did some more testing on the boat today and im pretty confident that because both of my flappers/shutters are missing, and the previose impeller in the outdrive was missing all but one fin, that all of the missing components are either stuck in the engine " less likely" or in the bottom of the y pipe " more likely. "

and just by thinking about my problem " getting plenty of water in, but basically not getting any water out of the exaust in releife ports or thru hub.

so my Question. with the drive on, and the manifolds and elbows off, can i insert a shop vac hose down the y pipe and turn it on, then from the out side of the boat shoot water out of my pressure washer 1800-4800 psi, into the exhaust relief ports to break free any debris or parts and force them up the y pipe and into the shop vac. will this cause any damage to the outdrive or engine?

thanks for youre replys guys.

while i have the manifolds and elbos off " old log style " im going to replace them with new center rise units even though they test out to be ok.

 

[MarkSee]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

Seems to me with the potential of those kind of parts that might be stuck, you'd want to try something more along the lines of a "snake" to run down the Y pipe and 'feel' if you run into blockage or it makes it to the bottom. Having some kind of brush attached on the front that is almost the same width as the Y pipe would be ideal.

I have a 4 inch vent pipe for my dryer that runs underground 20 feet from the garage where the dryer is to outside in the backyard and 1-2 times a year, it gets really blocked with lint and I have a 4 inch brush-end with 20 feet of cable that I run back and forth through the pipe to clean it out. Takes a few times to loosen it all up.

With the drive raised all the way up, the exhaust should be clearly accessible to also try from that side running a snake up through.

I'm just not convinced that a shop vac or high pressure spray is the way to go with those hard parts potentially stuck.

Mark

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

Seems to me with the potential of those kind of parts that might be stuck, you'd want to try something more along the lines of a "snake" to run down the Y pipe and 'feel' if you run into blockage or it makes it to the bottom. Having some kind of brush attached on the front that is almost the same width as the Y pipe would be ideal.

I have a 4 inch vent pipe for my dryer that runs underground 20 feet from the garage where the dryer is to outside in the backyard and 1-2 times a year, it gets really blocked with lint and I have a 4 inch brush-end with 20 feet of cable that I run back and forth through the pipe to clean it out. Takes a few times to loosen it all up.

With the drive raised all the way up, the exhaust should be clearly accessible to also try from that side running a snake up through.

I'm just not convinced that a shop vac or high pressure spray is the way to go with those hard parts potentially stuck.

Mark

worked on the boat a little more this weekend before the snow! i tried to run an electricians snake through the y pipe from the top. i got in about 20 inches on both side and it stopped. i tried for another 2 houres to fish the snake all the way up the other side of the y pipe with no succes. something is definatly blocking it. is there some sort of flapper or shutter at the bottom of the y pipe? or should i be able to pass the snake through?

thanks for the tips and help guys.

 

[Don S]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

Have you removed the whole outdrive from the boat and looked into the Y pipe?

 

[Bass2mouth]

Re: alpha one no or very very little water exiting through prop or exhaust relief po

Have you removed the whole outdrive from the boat and looked into the Y pipe?

no i have no removed the out drive from the boat.

not to side track but i was wondering, if i do remove the out drive from the boat and bring it into my garage is their anything on it that i can service? im just thinking if im going to absolutly have to remove the outdrive i would like to do bellows, shift cable, bearing. and anything else?

dons thank you for youre reply. you must be loving this mass snow as much as i am.