Sea King Impeller Fix

[Customline]

Hello,<br /><br />I have a 57 Sea King 5 hp. It's in fantastic shape. Except for a few minor scratches, it looks like it just came out of the box. <br /><br />Anyway, my dilemma is this. The impeller gave out the other day (just 10 feet from shore, thank goodness) and I am wanting to try and switch it out myself.<br /><br />I took the prop off and the lower unit bolts. The problem is, to get the impeler housing open, I need to take the lower unit off completely. Where I am running into trouble is with the shift rod; it prevents the lower unit from coming all the way apart. <br /><br />Can anyone help me figure out how to get to the impeller? Do I have to take the powerhead all the way off?<br /><br />Any help would be appreciated.<br /><br />Happy Boating!<br /><br />Doug

 

[Paul Moir]

Re: Sea King Impeller Fix

Welcome back to Iboats, Customline!<br />Your 5hp Sea King was manufactured for Mongomery Wards by Gale. Gale was a division of OMC, who also made Johnson and Evinrude engines. So your engine is almost identical to a mid-50s Johnson or Evinrude 5.5hp.<br />On those engines, you must remove the powerhead to access the shift rod coupler. So you'll also need a new powerhead base gasket to complete the job. NAPA or Iboats part number 18-2901 should be the correct gasket, or Bombardier PN 313065, which looks like this:<br />

<br />Be careful removing the powerhead, as the lower crank seal stays on the driveshaft and is composed of a few parts. Carefully note the order of those parts on before taking them off. There's a pin through the driveshaft holding them in place, and you'll have to turn the driveshaft to align that pin with a slot in the midsection so you can pull the lower unit all the way off.<br />The impeller should be 18-3001, or 18-3202 for the water pump kit.

 

[Customline]

Re: Sea King Impeller Fix

Thanks Paul! Fortunately I have the owner's manual, so I at least have a break-down. Another quick question... <br /><br />I have a feeling it ran for a couple of minutes after the impeller went out. I started losing power at full throttle. The owner's manual has a little blurb on that. It says to check for water discharge and if there is none to stop the motor. <br /><br />Of course I didn't read that until I got home after this mess. I thought maybe I had some bad gas because it was my first run since I stored the motor last January (I'm a duck hunter, and it was opening day).<br /><br />Do you think I could have damaged anything from overheating? Head gasket? Would a compression check rule this out? Should I check anything else?<br /><br />Thanks again for the help. You saved me a lot of headaches!<br /><br />Doug

 

[Paul Moir]

Re: Sea King Impeller Fix

It's possible that the overheat damaged the pistons and bore, or blew the head gasket. A compression test will show if either of these things happened by showing uneven or low compression. Crank the engine at least 4 or 5 times with the pull starter for each cylinder. Generally speaking, you want to see 90 psi or better and less than 10% variation between cylinders. Report what you get to us anyway.<br />If the compression test shows damage, then it's time to remove the head and determine the condition of the head gasket and the cylinder walls. If it's the head gasket, it's a simple and cheap matter to replace it.<br /><br />For the future, you really want to be replacing that impeller every couple of seasons. As they get old, they tend to fly apart. I try to carry a spare and the tools to replace it with me when I go out now, after shreading an impeller this summer and loosing a fun weekend. The spare was sitting on my workbench at home.<br /><br />You should be looking into getting a service manual for that thing. Iboats carries aftermarket Johnny/Rude ones that would be pretty good. Or you can get the original Gale one from one of the following places:<br />TheOutboardWizard<br />Mastertech<br />Marine Engine<br />Ken Cook <br />They're far superior to the aftermarket ones, and are specific to your engine. But they do cost more. If you can't wait to get one, you can often borrow a service manual from your local library.

 

[Customline]

Re: Sea King Impeller Fix

Thanks Paul! I will check it out. Those web sights are great. I ordered the aftermarket manual shortly before you posted. Now I wish I had held off and ordered the model specific one. Oh well. I'm sure it will work.<br /><br />I may just oder a gasket set. I noticed the gear oil was milky. I just changed it before going out, so I must have some old seals.<br /><br />I just love this old motor. I bought it for $100 from a lady whose husband had passed away. He owned it since new and used it only one week a year, fishing in fresh water on his vacation. It even came with the stand and owner's manual.<br /><br />Thanks again. I will let you know how it goes.

 

[Paul Moir]

Re: Sea King Impeller Fix

Ok, I get it. <br />If you're getting the Seloc manual, I find it's not bad at all. I frequently use it in conjuction with my OEM ones.<br />It often helps to know where the leak in the lower unit is before you disassemble it. First, be aware that the most common source of leaks are from the fill/drain screw gaskets (nylon), which should not be reused. $2 here might solve your problems. But if the case is really leaking, try pressurizing the case and submerging it. Bubbles will point to where the leak is. This can be done with a bicycle pump and a tire valve stem carved to fit one of the fill/vent screw holes. You can also use this arrangement to see if the case is watertight when you rebuild it: pressurize it to 3-5psi, and see if it can hold that pressure.<br /><br />Good luck, I'm keen to hear what you find!

 

[Customline]

Re: Sea King Impeller Fix

OK... Cylinders are at 65 pounds each. Exactly. I guess that's good that they are the same, but it seems a little low. Maybe because the engine is dead cold?

 

[Paul Moir]

Re: Sea King Impeller Fix

Ah, yeah, that's not so great.<br />If the head gasket blew, I would expect to see a lower reading, and more likely an uneven reading. At this point I thing you should put the impeller in and get it back together and try it out.<br />You could also try removing the exhaust cover to get a look at the side of the piston and the bore walls through the exhaust ports. But you'll need a new gasket from the dealer to put the plate back on. Or cut one yourself. <br />When an engine overheats, the pistons expand and start scraping on the cylinder walls. There'll be heavy marks along the sides of the piston and bore walls if this happened.<br />Did the engine totally seize while you were out, or ever stop? If so, was it hard to turn afterwards?

 

[Customline]

Re: Sea King Impeller Fix

Nope. It didn't seize. It just slowed down and stopped. It wasn't hard to turn over afterwards at all. In fact when I got it home to check it out, it started right away in the barrel. That's when I noticed it wasn't spitting out water. Well, I have an impeller ordered. I will throw it in on Saturday and start her up. I really hope nothing is damaged. Thanks again Paul.

 

[Paul Moir]

Re: Sea King Impeller Fix

Well, that's good news then. Probably was always at that compression - it's an old engine afterall. Forget about pulling the exhaust cover. There's probably nothing to see there.

 

[rodbolt]

Re: Sea King Impeller Fix

hello<br /> do what paul says. however be aware that OMC used 3 types of seals on the fill and vent plugs over the years. the early type plug had a flat smooth gasket surface and needs a paper composition type gasket. the second had a small "ripple" around the face and used a nylon washer. the third had a groove machined under the head and used an oring. the three gaskets dont interchange well. but if used with the proper seal/gasket on the right screw any can be used. so make sure someone has not changed one for the other or you may have an unintentional leak.<br /> good luck and that old motor was a hoss.

 

[Customline]

Re: Sea King Impeller Fix

Thanks rodbolt. I will check it out. That's one of those little things that are valuable to know.

 

[Customline]

Re: Sea King Impeller Fix

Success! The new impeller went in just fine. It was a bit more involved than I thought. And to think that the repair manual suggests changing that out annually. I hope the process is a little quicker on my '92 evinrude 8 hp. We shall see. Thanks for the help and the responses. It is much appreciated.