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1975 Johnson 9.9HP Project

BRUPP79 said:
Nice idea Tim. I woulda done the "tap and check method" back and forth till I over did it:rolleyes:. I will have to remember this.
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A thank you to Tim, too. I know I can get that O-ring out. My worry was how to install the new one. I am ordering it tonight. In the meantime I will rebuild the carb.
 
What is the nut diameter to pull the O-ring out? Can someone that has a working puller measure theirs?

The bushing has been soaking in PB-Blast for a couple of days and seems corroded in place.

Photos of my puller tool are attached.

Puller Tool End.jpgPullerTool.jpg
 
I own both a 9.9hp 1975 and a 15 Hp 1976. Two important things I found on my motors, others have had different experiences. The recommended Champion spark plugs don't last. I always use the NGK B7HS for the 9.9Hp and the B6HS for the 15 Hp.

Whatever plugs you use, these motors really do not like trolling for long periods of time. They will do it but even with NGK plugs you will probably foul one of them in a day or two of trolling. I always change out the plugs every two years for sure. My motors don't get a lot of use so if I was fishing every day I would make it an annual thing for sure. Keep an extra set of plugs in the boat, but with that said, usually if you foul one, it is only one. Depending on how far from your dock you are one cylinder will usually get you home and changing plugs in the lake/river is a PITA. I always open up the throttle to WOT for 30 seconds before I bring her to the dock in hopes of burning off any carbon that might be building up.

I like to reset the points gap every 5 years or so. It tends to drift a little with use and there is a noticeable improvement in power when they are set right plus it probably helps a little in reducing carbon build up on the spark plugs.

Other then that, they are very reliable motors. If you use the right plugs you should not have any problems.
 
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racerone said:
It is a 5 minute job to replace that o-ring.-----If it is 45 years old you need a new one !
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racerone,

You owe me a beer. 5 minute job my *****. I have been heating, PB Blasting, and slide hammering that bushing for two weeks. :D

It will come out eventually.

The good news is that the engine is coming back together. The carb, recoil starter, and tiller throttle are rebuilt and installed. :cool:
 
Run a 5/16-NC tap in there and pull it out with threaded rod.--------Actually the o-ring can be changed without removing the bushing.
 
Really....how's that? Like pulling a golf ball through a garden hose? Damn.....your a way better man than me, Racer.
 
Sure, almost anything is possible, but it would be fun to know the technique...... especially if it can save time and effort. They didn't teach it in schooling,....... years ago.
 
racerone said:
Run a 5/16-NC tap in there and pull it out with threaded rod.--------Actually the o-ring can be changed without removing the bushing.
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It finally came out! I ended up using a puller head across the top of the lower unit instead of a slide hammer. Now comes the fun part, reassembly with new seals.

IMG_1131.JPEGLowerUnit.jpg
 
Did one of those reseal jobs for a neighbor about 30 years ago.-----When I walked over to return it he said ----" done already ? "-------Motor was still on the back of the boat couple of years ago.----Did not use any special tools other than 1/4" rod with a modified nut to pull the bushing.
 
That's awesome.

While the shift rod bushing was soaking in PB Blast I finished the top end.
-Carb Rebuilt
-New fuel lines
-New recoil rope
-Set points and gapped plugs
-Cleaned and relubricated the tiller handle

Hopefully I can tank test soon. Today I realized that the intake water screen was missing so I just ordered it.

PowerHead.jpgIMG_1117.jpg
 
racerone said:
Intake water screen is shown in place in your last picture of post #39 ???
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You are correct. I expected it to up top near the water pump.

The good news then is that I don't have to wait for it. I might be able to do a tank test this weekend.
 
MAN.....Racer your sharp! Your still on top of things. Like that long tiller too, nice swap. I'm gonna put my 15 together in a couple weeks. Looks like it's gonna warm up soon, but snow again tonight and tomorrow. Beauty motors....I like the 74/75's.
 
A little more progress today. I built the special tool to noodle the shift fork back into position. I will provide DIY info on that tool later in this thread. Hopefully it saves someone about $50. The tool can be built for about $10 max.

After I built the tool I resealed and reassembled the lower unit and touched up the prop. All that's left to do on this motor is:
1) Install the shift rod O-ring seal, washer, and bushing;
2) Install the new water pump kit;
3) Bolt the lower unit to the upper; and
4) Tank test and tune.

I am stoked. :)

Shifter.jpgSealed.jpgProp.jpg
 
Special tool ??----I just turn the gearcase upside down and gravity put the shifter in it's place every time.----Done it countless times with no issue !
 
Okay then, Racer.....please show me how to change that shift shaft o-ring.....without bushing removal. Do you slightly enlarge the lower opening and pull it through.....up into its space?
 
The rubber 0-ring will stretch and fit through the hole.------Nothing to it really.----I showed an OMC repair guy a trick to repair electric shift springs years ago.----He said " in my wildest dreams I would not have thought of this simple method "----Bought the tool from me on the spot.----His card said 30 + years of OMC experience.-----But others have scoffed when I suggested that it could be repaired.-----The factory manual says install new spring , therefor it can not be repaired !
 
racerone said:
Special tool ??----I just turn the gearcase upside down and gravity put the shifter in it's place every time.----Done it countless times with no issue !
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I can do that now that I have a feel for what's going on in the lower unit. This is my first time working on one that is this small but still has an F/N/R fork and clutch dog.

My previous lower unit experience is with a ~ 1978 Evinrude 2HP, a ~1976 Evinrude 85 HP, and a ~ 1977 Volvo-Penta AQ270 I/O. They all have their quirks with how to put 10 lbs. of $%^# in a 9 lb. bag. :D Refreshing this motor has been a fun experience.

Today I installed the water pump kit. Tomorrow I plan to reinstall the lower unit, tank test, and dial in the carb and ignition twirly plate linkages. :cool:
 
Made a little progress today. I put a fan near the engine so that it is not rebreathing its own exhaust.

The two big things that I discovered were:

1) The thermostat was stuck open and the engine block was only reaching 82 deg F. I replaced the thermostat and now the engine block is steady at about 140 deg F.
2) I raised the fuel tank off the ground so that the fuel pump would not have to work as hard. The head height now is similar to what it would be in the boat.

The engine is happy now with the throttle in the "START" position in neutral and in gear at higher speeds. It conks out within a few seconds when the throttle is reduced to the "SHIFT" position.

I am guessing the carb slow idle circuit is plugged. What do you guys think?

TStat.jpg Temp.jpgTank.jpg
 
My service manual says tank no lower than 30" from pump...and from my experience that is pushing it.

Yep...sounds like a carb service is in order.
 
Carb service did the trick! When I rebuilt the carb a few weeks ago I was afraid to remove the plugs and clean the idle circuits. This time I had to do it because it seemed that is where the problem was. Photos of the process are attached.

1) Drill the old plugs to receive a sheet metal screw.

Carb1.jpg

2) Insert the sheet metal screw about 3/16" and pry to pop the plug out. Thumb pressure was sufficient for me.
Carb2.jpg

3) Inspect for debris then clean and dry with compressed air. This is what one of my circuits looked like when I opened it. The speck at the bottom of the well is the only dirt I saw.
Carb4.jpg

4) Insert new plug dome-side up and use a punch to flatten it into position.

Carb5.jpg

Here is the boat ready for a lake test. I hope to do that Monday or Tuesday.

Boat.jpg


Here is the engine idling in gear after cleaning the idle circuits. https://www.facebook.com/ed.bacon.399826/videos/948833525946266
 
Lake test is done. The engine runs well in gear at all throttle positions except about 1/4 throttle. It conks out there. I think the timing needs to be advanced just a few degrees. When I put the new points in I gapped them .022" per the manual for new points. The timing was perfect when I first started the engine but as the points break in the timing has retarded a few degrees.


Thanks everyone for your help!

High speed run: https://www.facebook.com/100024588823043/videos/951266932369592/
Trolling idle: https://www.facebook.com/100024588823043/videos/951266959036256/
 
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