How to check sea water flow.

[HutchNJ]

Have a '87 Merc 165 I4 and will be changing out the impeller tomorrow. With the lower unit off is there a way to use a hose to check flow through the heat exchanger / riser and out the exhaust before I reassemble?

Thanks for all the help so far ....

 

[Bondo]

Re: How to check sea water flow.

Ayuh,... Sure,.. Flush it forward,+ back flush it...

I'd start with back-flushing from the HE back to the outdrive...
If there's restriction in the Riser,...
Removal,+ cleaning is going to do more than just flushing it out...