Seawater pump replacement on a Yanmar 3YM30

[RVLA]

Hi folks. I just joined the Board to ask this question. The seawater pump on our Ranger 21EC’s Yanmar 3YM30 seized on me but fortunately we noticed it and shut it down immediately. I have a replacement pump on order but can’t seem to locate the ball valve (seacock) indicated in the manual. The manual shows the valve is in the round deck hatch outside the bulkhead door. I’m pretty sure that I can join the hoses together temporarily while the pump is out but I’d feel much better shutting off the intake. I’d prefer not to pull the boat out for the repair. Any words of wisdom?

Also, can a semi-competent mechanic (me) rebuild the seized pump for a spare? It’s a Johnson F4B-903. I understand this model has been upgraded to address the very problem (bearing seal) that’s afflicting us.

 

[MichaelStrotz2]

The seaclock valve is where you looked. Reach in the round hatch. When you are on your knees in the cabin, facing aft, it is just to the right, slightly out of sight to the right. When the handle is in-line with the centerline of the boat, the seacock is open. This is the position it should be in when you are operating the boat. To close it, turn the handle 90% so it is crosswise to the hull centerline.

 

[RVLA]

Thank you for the reply. I was able to find it after groping around a bit. Funny that they didn't coordinate the hatch and valve placement. On a related matter... someone told my spouse that we should close the seacock after every outing. It seems like overkill and a recipe for venturing forth without cooling but she'll believe anything as long as it wasn't voiced by her husband. In my mind it's probably like crashing your computer without frequent backups - great advice when you need it but a bit of a pain otherwise. I'll put it to the group, does it make sense to close the seacock after every use?

On an unrelated matter, our R21 has an alcohol cooktop. Has anyone replaced theirs with an inductive cooktop? Seems like even if it's 120v it might be safer and more useful. Something about an open flame just doesn't seem prudent.

 

[Messenger]

I'll put it to the group, does it make sense to close the seacock after every use?

No it does not. If it is not in your daily routine to open the seacock you will most likely forget to open it spelling disaster for your raw water pump and perhaps an engine. HOWEVER, if you keep your boat in the water for weeks or all season, then yes, close the valve after use AND put a huge reminder somewhere you will see it. Maybe a pre-trip list of a couple of absolutely necessary steps to do before firing the engine.

On an unrelated matter, our R21 has an alcohol cooktop. Has anyone replaced theirs with an inductive cooktop? Seems like even if it's 120v it might be safer and more useful. Something about an open flame just doesn't seem prudent.

I posed the same question but got no response. We have a grill mount for the stern handrail and cook everything there. That alcohol stove is totally inadequate at best.