1956 Johnson 5.5 hp water pump replacement

[oshkosh]

I have a 1956 Johnson 5.5 hp motor that my dad had it refurbished in the late 1990's (new hoses, spark plugs, etc). I ran it for awhile around 1999 after a complete engine overhaul - maybe 10-15 hrs of operation - then back into storage it went when I bought a bigger boat. My 16 year old now needs a boat motor for his 12 foot rowboat for his fishing trips and I want to bring the engine back to life.

I noted that it pumped water poorly towards the last of its service in 1999 so the water pump needs replacement. When I went to remove the lower unit assembly this morning I ran into some difficulty trying to get the upper splined shaft to release - it seemed locked into the gear engagement pinion.

I had an exploded view from the owner's manual (bought the full manual a few minutes ago at iboats) but still curious if anyone else has had a problem pulling the lower unit down. I would have expected the splined gear at the top to just pull out - should I employ a gear puller? I would rather not have to employ professional help to do this job.

 

[jbjennings]

Re: 1956 Johnson 5.5 hp water pump replacement

I believe you have to pull the powerhead to disconnect the shift shaft from the linkage just underneath the powerhead. You'll need a new powerhead base gasket.
Good luck,
JBJ

 

[oshkosh]

Re: 1956 Johnson 5.5 hp water pump replacement

jbjennings,

Thanks for the post - it sounds too involved for my capabilities as I don't have extensive small motor experience. I'm considering letting a Pro take care of it from here, but I may wait until I get the parts manual I ordered to see if it would help describe the order of disassembly with regard to detaching the shift shaft from the linkage as you describe.

I do alot of work on appliances - but there are no engines in the them and I don't dunk the appliances in the water, just put water in the appliances.

 

[jbjennings]

Re: 1956 Johnson 5.5 hp water pump replacement

OShkosh,
In the time it took to type your message, you could have removed the high and low speed adjustment knobs, pulled the choke knob off, took the fuel lines off the carb and intake, take off the slotted lever that holds the shifter in gear, and remove the throttle lever that attaches to the ignition armature plate, and used a good-fitting flathead screwdriver to pull the powerhead. It's not hard, believe me. EVERYTHING will come off with that powerhead so I'd try it if I were you. Those engines are really fun to work on and really easy. You CAN do it, unless you are completely UN-mechanically inclined. If you have a question about something while you're working on it, just ask. Most of the time you'll get a response in just a few minutes because most guys here know every inch of that motor. Ask and someone might even send you a parts manual pdf so you'll know what part #'s you need.
Good luck either way,
JBJ

 

[oshkosh]

Re: 1956 Johnson 5.5 hp water pump replacement

Your description is well within my capability. it's coming apart tomorrow. The manual I bought was useless. It stated "to replace your water pump take it to a qualified Johnson motor dealer....."

I talked to three guys who have outboards for their entire lives and they said it would be a snap, so we will see how it goes.

I do think my motor must be somewhat newer, although my Mom says it showed up about the same time she got married (1956). The cover is (1) pc not like the owner's manual (2) pc. Model is CD 19 :redface:S; serial number 2294340.

I appreciate your words of encouragement.

Oshkosh

 

[freddyray21]

Re: 1956 Johnson 5.5 hp water pump replacement

cd 19 is a 1962, but the same thing applies to taking the powerhead off. Great motors

 

[oshkosh]

Re: 1956 Johnson 5.5 hp water pump replacement

LBJ,

In 30 minutes I had the power assy off. Definitely glad I got the gasket recommended by the post earlier. My Johnson dealer had it in stock and I was surprised it was only $5.25. I got a full photocopy of the 1962 parts manual for $8 along with it, worth every cent. For the record, the gasket is considered an obscure part in the Johnson computer, not necessarily stocked by most dealers.

I don't do alot of work on engines, so a few quick questions:
-after pulling off the power assy, there is quite a bit of oily gunk laying around inside - should I remove and leave clean as a whistle?
If I clean it out, any oil recommendations to toss down on the gear spline etc? Just typical light lubricating oil or does it have to be thicker?

The gasket is a going mess. I'm temped to drag a razor blade carefully along the edge, but don't want to risk a cut. I was thinking maybe a plastic spatula might be a better option. Thoughts?

 

[wbeaton]

Re: 1956 Johnson 5.5 hp water pump replacement

Try to remove as much of the old gasket as you can. I used gasket remover and a plastic spatula in my early days, but now I just use an old piece of disgarded razor blade from my utility knife. Whatever you choose be careful.

Use some white lithium grease on the dirveshaft splines or water resistant grease like you use for your trailer axle hubs (that's what I use).

Also, replace the cork gasket and o-ring that make up part of the lower crankcase seal located on top of the driveshaft. They are parts number 1 and three in the attached photo. The part numbers are as follows.

Cork gasket BRP 303355 (Sierra 18-2892)
o-ring BRP 303347 (Sierra 18-7180)

I restored and sold a 1962 Evinrude 5.5 hp a couple years ago. What a beautiful running motor it was. Very quiet for the year.

Good luck.

 

[oshkosh]

Re: 1956 Johnson 5.5 hp water pump replacement

wbeaton,

I just finished putting it back together this 1962 motor. It's in better shape internally than I thought it would be.

Ironically I took a hard look at that cork seal you describe. The cork seal was a bit worn, but not cracked. If I had known before the boat shop closed that it too would be a wise choice to replace, I think I would have replaced it too. After about 3-4 hours of tinkering, cleaning (probably way more than I should have) it's just about ready to go.

Things I learned along the way:
-watching the video of the Marinedoctor helped to know to put the impeller in the housing first, then over the shaft (shaft turns clockwise) - went right in
-scrapping the power head gasket off is a tedious job (60 min). I think I cleaned it up pretty good, but what a pain!
-it took a little bit to align the shaft to the power head- but once I figured it out it dropped right on. If I had a 3rd hand to turn the prop it would have been much quicker.
-very easy to strip the gas inlet line plastic part that holds the gas line to the frame of the motor - now needs to be replaced - but pretty easy to do.
-putting the cotter pin back in the choke is not easy to do, but after a struggle, I got it.
-I couldn't remember if the fuel lines routed outside of the the throttle lever tie in or inside - seemed to work best with the lines on the outside - next time take digital photos before disassembly
-what a hokey key at the pump - never seen one done like that, but it does work.

Last things to do with a few questions:
1) J6C spark plugs are in it - but was thinking of replacing - anyone know the gap setting?
2) what is the appropriate oil to gas ratio. Motor shop said 50:1, the literature said 24:1?
3) I have 9 year old oil from when I ran it last. Does oil have a shelf life? Would I be better off chucking out the 8 or so quarts and buy new? This motor sips gas and I never came close to using up the case I bought after 2 summers.

 

[jbjennings]

Re: 1956 Johnson 5.5 hp water pump replacement

The plug gap is .030 inches.
The oil ratio is NO LESS than 24:1, not 50:1. If you run 50:1, you will likely ruin that motor.
I would use the 9year old oil if it was from an unopened container.
Glad you got it fixed! I'm suprised you were told 50:1 by a shop on that motor.
JBJ

 

[oshkosh]

Re: 1956 Johnson 5.5 hp water pump replacement

lbj,

Your paragraph of directions worked great.

One other minor issue, the white knob adjustment on the lean/rich won't turn. I messed with the linkage quite a bit and it looks like the exploded view in the manual, but doesn't turn. If I can get the motor going, I may try to get it going once it warms up.

Going to try and fire it up around noon today running in a water filled trash can.

 

[wbeaton]

Re: 1956 Johnson 5.5 hp water pump replacement

The two seals I had mentioned are of vital importance to the health of your motor. Without a good seal in that area water can and will get into the crankcase and destroy the motor.

I use synthetic oil at 24:1 since it smokesless and is more environmentally friendly. I'd just use up what unopened oil you have.

I believe you should have two mixture adjustment knobs on your motor. One for high speed and one for low. The high speed has no linkage. The low speed does. Disconnect the linkage and see if you can turn the low speed jet by hand. If not, then loosen the nut at the base of the jet and try again. The nut is for tensioning the jet. If this doesn't help then you will have to disassemble the carb. After so many years in storage you may well find that the carb needs to be cleaned.

 

[lindy46]

Re: 1956 Johnson 5.5 hp water pump replacement

One other minor issue, the white knob adjustment on the lean/rich won't turn.

If original, those packing nuts are probably hard as a rock. I'd get a carb kit and clean/rebuild the carb.

 

[oshkosh]

Re: 1956 Johnson 5.5 hp water pump replacement

It's Alive! Blew 8 years of smoke out that first few minutes, but now runs just about smokeless after just 5 minutes of idling. I did opt to go with new oil and planted the old stuff in the recycling station. Tank is 3 gallons so 24:1 is a perfect fit to a quart of oil.

Forward and reverse run well. Starts on the first or second pull, better than I thought it would. Low end idle could use some adjustment and will probably require that carberator rebuild mentioned above.

I think I will go back in after the o-ring and cork. The o-ring was in excellent condition, but if I'm there changing the cork, I'm changing the o-ring too. The water pump works great - spitting a nice stream out. I also think I will change the lower unit oil again after about 1 to 2 hours of operation, using the new stuff to "flush out" the old stuff thoroughly.

Now on to installing new transom wood (1" treated plywood w/marine primer and marine battleship grey paint) on the boat. Making sure the boat floats and is licensed is the next order of business.

A very happy 16 year fishing crazed guy is happy with what he sees so far.


oshkosh

 

[wbeaton]

Re: 1956 Johnson 5.5 hp water pump replacement

That's great news. You might find that all it needs is the carb to be adjusted while on your boat. Keep an eye on the lower unit oil for water intrusion. +50 years is a lot to ask of an oil seal. A reseal kit is about $30 and will take you an afternoon. Not hard to do, but its a pain until you do a few.

 

[oshkosh]

Re: 1956 Johnson 5.5 hp water pump replacement

Good tip about the oil seal - I'll put it on the "rainy day" agenda.

Oshkosh

 

[Doncc]

Re: 1956 Johnson 5.5 hp water pump replacement

Thanks to all for the valuable information posted here regarding the step by step water pump impeller replacement.

 

[ci2hi]

Re: 1956 Johnson 5.5 hp water pump replacement

I am new to this type of thing but have read the thread because I was having trouble removing my lower unit on my CD-17 since it didn't have the access plate on the side like some of my other outboards. I decided to tear into a parts motor and had the powerhead off in about 5 minutes. With mine I didn't have to mess with the high and low speed jets or the linkage to the throttle plate since it's all connected and the throttle shaft simply fits into a slot. But to get to my quiestion, I have a exhaust housing gasket located which is sierra part number 18-2901. What I question is part number 18-2892 which my Sierra book describes as a filter bowl gasket. Would this be an identical part that coincidentially is used for the top of the drive shaft to seal it from the crankcase? When I removed the lower unit there was a spring with a black shouldered fiber collar. Does the gasket fit between the fiber collar and the bottom of the crankshaft where it mates? The other recommended (O-Ring part # 18-7180) part seems pretty generic. In fact I see the same part number used on several models. This is a great site with vurtually unlimitted resources. I hope I can, now that I'm a member, be of help in some capacity.

 

[wbeaton]

Re: 1956 Johnson 5.5 hp water pump replacement

I am new to this type of thing but have read the thread because I was having trouble removing my lower unit on my CD-17 since it didn't have the access plate on the side like some of my other outboards. I decided to tear into a parts motor and had the powerhead off in about 5 minutes. With mine I didn't have to mess with the high and low speed jets or the linkage to the throttle plate since it's all connected and the throttle shaft simply fits into a slot. But to get to my quiestion, I have a exhaust housing gasket located which is sierra part number 18-2901. What I question is part number 18-2892 which my Sierra book describes as a filter bowl gasket. Would this be an identical part that coincidentially is used for the top of the drive shaft to seal it from the crankcase? When I removed the lower unit there was a spring with a black shouldered fiber collar. Does the gasket fit between the fiber collar and the bottom of the crankshaft where it mates? The other recommended (O-Ring part # 18-7180) part seems pretty generic. In fact I see the same part number used on several models. This is a great site with vurtually unlimitted resources. I hope I can, now that I'm a member, be of help in some capacity.

The filter bowl gasket is neoprene (rubber). It is not the same as the cork gasket of the lower crankcase seal. The o-ring that fits in the carbon seal, which you called the fibre collar is generic. Nothing special about it. The spring fits in the big end and the o-ring fits in the other. See the lower crankcase seal assembly photo I posted above.

 

[ci2hi]

Re: 1956 Johnson 5.5 hp water pump replacement

I have the 2008 Sierra catalog and I just don't want to order a bowl gasket if I need the cork one that you describe. I saw no evidence of there having been a cork gasket there. Maybe it had been disassembled at one time and the cork gasket not replaced. But on page 217 there is a diagram that gives the sierra number of 18-2892 and the OEM number of 303355. It describes it as a bowl gasket. What am I reading wrong? By the way, thanks for the quick response. John