Water flow problem after lower unit replacement...

[randy2112]

OK, I got a replacement lower unit for my 1977 Electric shift... Yeah, I know... Well there seems to be a restriction in the water passage... the adapter I use goes in the water pickup just above the prop... before it worked just fine even with the hose turned on all the way. Now after installing the new unit with all new seals the hose builds pressure and pops out of the water pick up... I didn't touch anything in the upper and it was not removed from the boat. The lower unit tube is clear and as far as I can tell nothing is able to get in the way of the water flow in the lower unit. The cooling system worked fine before the swap so what could it be? Also the lower unit doesn't shift... Everything feels nice and smooth. but when I put it into forward or revese nothing happens... If I put 12v to the wires I cant hear anything happen but the two shafts seem to grab each other. what can I do too test the coils?

 

[Redrig]

Re: Water flow problem after lower unit replacement...

what can I do too test the coils?

Use a multimeter and test the OHMs on each of the wires, should be 4.5 to 6.5 ish.

are you sure that the pickup tube on the new lower is clear ? thats the only thing that you really changed that could cause the hose back pressure. Is the screen all gunked up ?

 

[Redrig]

Re: Water flow problem after lower unit replacement...

And by the way, you can install a Tee on the hose that runs from the outdrive up to the thermostat housing (starboard side) and connect your hose there. I am not sure what kink of adapter you are using to run the hose to the lower.

I use the tee method and it works great and only costs a couple of bucks at any parts store.

Prestone AFKIT - Flush & Fill Kit | O'Reilly Auto Parts

 

[randy2112]

Re: Water flow problem after lower unit replacement...

Hi, I did some checking and the coils are 5.5 and 5.4 ohms. I put 12v directly to the shift wire, then tried to turn the prop by hand and the drive locks into both forward and reverse gear...

The boat came with a home made rubber hosething that fits snugly into the water pickup tube after you remove the screen...

I disconnected the water hose from the thermostat housing and ran water back through the out drive it flows fine. Perhaps the seals in the old lower unit were bad bleeding off pressure.

So the drive seems fine and the problem is now in the boat wiring but the shop tested it just before the drive swap and told me it was working correctly....

The boat runs so the factory fuse is good correct? were else would I find a fuse for the shift system? I really hate tracing electrical systems!

 

[Boomyal]

Re: Water flow problem after lower unit replacement...

There is info in the manual about servicing the swivel housing when doing an impeller change. They say failure to do so could inhibit water flow to the impeller.

 

[randy2112]

Re: Water flow problem after lower unit replacement...

Thanks, I will check that out.