Engine Flush

[firstcatch]

It seems as if I have a blockage somewhere in my cooling system.
I installed a new water pump and it seems fine. Ran the boat for a while yesterday with no problems. Good flow of water being pumped out.
However, when I try to flush the engine by attached a hose to the engine flush, no water comes out of the 'pee' hole.

Do I just need to trace the line to find the blockage or is something worse going on?
Any ideas on how to free the blockage without starting to take things apart?

Thanks for your ideas.

 

[99yam40]

you can try blowing so compressed air up the tell tail while flushing to see if that will move the blockage aroung some.

may be you just do not have enough water flow on the hose

 

[firstcatch]

you can try blowing so compressed air up the tell tail while flushing to see if that will move the blockage aroung some.

may be you just do not have enough water flow on the hose

There is enough water flow in the hose because the other engine (twins) pees just fine.

 

[firstcatch]

Bump.
Anyone have any ideas.
One engine won't pee when connected to flush out hose. Other engine pees fine so I know there is plenty of water pressure.