How to clean water passages.

[Whitey78]

I have a 1971 4hp johnson that I have had for a couple years with no problems. Other day I forgot to lift the motor up when beaching it on a sandy beach, and I think is now overheating due to sucking up sand. A bit of water is squirting from one side of the 6 holes on the leg. The motor starts up no problem when cool but after running it full throttle its starts bogging out and stalls. Is there a way to clean out the water passages? I thought maybe it was the carb but when i took it apart it looks good in there. i have a bit of gas leaking from the high speed idle screw think that could be the problem? Was thinking about buying a impeller and plate but they seem to be pretty expensive and dont wanna spend that if its clogged in the water passages.

 

[oldboat1]

The sand will have destroyed your impeller. You need to replace it. While the lower unit is removed, force some water up the copper tube and let it flow out. Remove the cylinder head, and spray water in the passages, scraping out and rinsing any clogging. Finish by running at idle in a barrel of clean water.

 

[Whitey78]

This is the first outboard I ever owned. I'm kinda worried about messing it up by removing the head. Maybe il just replace the impeller and spray up copper tube and see if that fixes it. Or is taking the head off not as big of a deal as I'm thinking it is?

 

[oldboat1]

If it's a salt water motor, soak the bolts in automatic transmission fluid (combined with acetone if you have it). Let it soak for a day or two, then use a box wrench to careful run the bolts back and forth until they -- hopefully -- loosen up. If you do it all at once, you are likely to break bolts.

Do not run an outboard at open throttle when you suspect it has overheated, or has blockages like sand, silt, or salt.

Get a factory service manual for your motor.