Block only drains on one side

[acdc96]

Lately I've been prepping my boat for the water after a long time sitting in my driveway. (5 plus years). I just cleaned and painted the manifolds and risers from rust build up. (Only took the risers off). I started the motor and let it warm up for 30min to check for leaks and fine tune the carb.
When I drained the engine the next day of water only water came out of the starboard side of the block and a small trickle came out the port side. I put a metal coat hanger up into the hole to unblock any debris but it was clear. Both manifolds dumped water perfectly as I expected .

I'm really stumped on this one, the boat and trailer are level. I tried leaving the port plug open when the engine was running but it still would not drain more than a trickle.
Is this normal or do I have a blocked passage in the block?

1987 Mercruiser 260HP 5.7L V8

 

[Idlespeedonly]

Re: Block only drains on one side

If you have an air compressor I would blow some air into the fitting. Dont forget about the appropriate safety gear.

 

[Bondo]

Re: Block only drains on one side

Lately I've been prepping my boat for the water after a long time sitting in my driveway. (5 plus years). I just cleaned and painted the manifolds and risers from rust build up. (Only took the risers off). I started the motor and let it warm up for 30min to check for leaks and fine tune the carb.
When I drained the engine the next day of water only water came out of the starboard side of the block and a small trickle came out the port side. I put a metal coat hanger up into the hole to unblock any debris but it was clear. Both manifolds dumped water perfectly as I expected .

I'm really stumped on this one, the boat and trailer are level. I tried leaving the port plug open when the engine was running but it still would not drain more than a trickle.
Is this normal or do I have a blocked passage in the block?

1987 Mercruiser 260HP 5.7L V8

Ayuh,... Start it up, 'n run it with the drain plug Out,....

 

[acdc96]

Re: Block only drains on one side

If you have an air compressor I would blow some air into the fitting. Dont forget about the appropriate safety gear.

I got one and going to try that. tight squeeze to get down their bit I will try.

I don't know if this will cause any harm to the inside of motor but could I use one of those "Rust Remover/Disolver" formulas that gets rid off the rust?
I've used it on a old B&S engine to free up a seized piston that rusted shut due to a flood. It worked good but discolored the piston. Of coarse I would remove all the hoses and other vanurable parts before dumping the solution down the thermostat hole.

 

[JustJason]

Re: Block only drains on one side

Listen to Bondo. that's the easiest way to see if it's blocked or not. But, if you got a screwdriver in that hole an inch or 2, then its not plugged.

 

[Idlespeedonly]

Re: Block only drains on one side

I tried leaving the port plug open when the engine was running but it still would not drain more than a trickle.
Is this normal or do I have a blocked passage in the block?

1987 Mercruiser 260HP 5.7L V8

Listen to Bondo. that's the easiest way to see if it's blocked or not. But, if you got a screwdriver in that hole an inch or 2, then its not plugged.

He has tried it with no luck.

 

[Bt Doctur]

Re: Block only drains on one side

Was the block left "dry" all those years? You could:
remove the engine circ pump and add water to the block there
remove the core plugs and flush/ clean from there
thread is 1/4 pipe, make an adaptor from a air hose and pressurize

 

[Bondo]

Re: Block only drains on one side

Originally Posted by acdc96
I tried leaving the port plug open when the engine was running but it still would not drain more than a trickle.
Is this normal or do I have a blocked passage in the block?

1987 Mercruiser 260HP 5.7L V8

He has tried it with no luck.

Ayuh,.... Does Open, mean the plug Out of the Block, nothin' in the block's hole,..??

If so, I'd isolate the Block, 'n pressurize it with water,....

No way it's That plugged up,....

 

[acdc96]

Re: Block only drains on one side

Update:
I blew air into all the drain plugs. I took out the left side drain plug and started the motor and let it warm up for 5 min and I saw a little bit of improvement. I reved the motor up to 2000 rpm and now it pours out great. Must of blew what ever was in their out. I repeated that process for every drain plug to blow the remaining particles out.

I did notice that the bottom of the manifolds where burning hot, and the risers where nice and cold. I'm gonna take all the hoses off and clean them and see if their blocked in any spot. I pressure tested the manifolds and no leaks! Although I have to replace the riser gaskets cause I have one leaking now.

 

[Idlespeedonly]

Re: Block only drains on one side

That is a lot of scale. Glad you got it.