Help with 1971 Johnson 6hp outboard

D

Donivan Wells

Active member
I got a great deal on a '71 Johnson 6hp that had a broken shift linkage. I've run the motor a few times now but I'm concerned that the impeller may be on the fritz....
usually when the motor is running, there is water coming from an exhaust outlet midway up the lower unit (there is also an exhaust port under the horisontal fin just above the prop). Sometimes it just blows hot exhaust. If I stop the motor and back flush water into the exhaust ports, when I restart the motor, it will again spit water from this port (see pictures).......

Anybody know anything about these motors??? Is there supposed to be water coming from this port 100% of the time it's running??

Any help would be appreciated!!!

Donivan

View attachment motor1.jpg
View attachment motor2.jpg
 
Yes there is supposed to be water coming out. This spray of water lets you know the impeller is working. DO NOT run the motor if there is no water shooting out of the hole. The impeller should be changed every other year or so depending on how much mud and muck you run it in. They get brittle with age and stop pumping. Not the end of the world for your motor
 
I have a 1971 rude 6hp got in 1979, great little motor. What Ron said, but I get a bit longer life out of an impeller, but put a new one in a used motor to start with. NAPA has then & other outboard parts. When ya change it, there is a small pin that acts as a key between the impeller & shaft, easy to drop& loose. Make sure the impeller fins bend the same way as the old one& make sure the water tube is in the rubber boot when ya reassemble it. One other thing to ck. Believe it or not these things have a thermostat! I had to replace mine last year, it stuck shut. If the bypass port is open it still sprays a bit of water out of that exhaust port tho. Its located in that round casting on the back of the block, above & a bit left of the spark plug wire hold down clip in the second pic. You can ck it out by placing it in a pan of cold water, then heating the water up. It should fully open before the water boils. NAPA can get these too. Good luck to ya
Dennis
 
Thank-you Dennis and thank-you Pastor Palmer.......Dennis, to change impeller do you just remove the 4 bolts holding on the lower unit???

I thought I read somwhere that you needed to pull the powerhead and unhook the shift linkage in order to drop that lower unit.....I just had that darn thing off to fix the shift lever linkage...
 
I thought I read somwhere that you needed to pull the powerhead and unhook the shift linkage in order to drop that lower unit.....I just had that darn thing off to fix the shift lever linkage...
Click to expand...


Donivan,

Yes, you need to uncouple the shift linkage. NO, you do not need to remove the powerhead to do this.

Best thing would be to go to BRP's web page and click on "parts" which will eventually bring up a list of motors. By choosing your motor, year, model, etc., you can eventually get to a screen which will give you an exploded view of all the parts and the order in which they are assembled.

A rough outline of what you generally need to do (your particular motor may vary slightly) to replace the impeller is;
(A) remove the bolts holding the lower unit on.
(B) the lower unit will drop down slightly
(C) move the shifter handle back and forth in and out of forward or reverse, one way or the other will allow the lower unit to move even lower, the other way will try to pull the unit upwards. You want it to move as low as possible so move the shifter that direction.
(D) now in the gap between the lower unit and the upper housing, you should see a coupler on the shifter rod inside the housing. Completely remove the cross bolt in this coupling.
(E) now you can completely separate the lower unit from the upper housing and proceed with the actual replacement of said impeller.

Take care that everything lines up and is in place during the reassembly process, just reverse the order to reassemble.

DISCLAIMER: I typed this rather quickly and I hope I didn't leave anything out. BRP's web site is real good at providing a good parts diagram.

 
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Good breakdown pic. Dave. When ya put it back together, put a bit of grease on the drive shaft splines & while your fimger is greasy- slick up the water tube where it slides into the rubber boot(#57 on Daves pic.) & be sure the impeller fins are bent the same direction as the old one. Looks harder to do than it is. Good luck to ya with your new(old) motor. & remember take spare shear pins with you for the prop.
Dennis
 
Ok guys......took out the 4 bolts and disconnected shift linkage but this lower unit is NOT dropping off......am I missing something????

Donivan
 
Donivan,

When you say you disconnected the shift linkage,,, Did you completely remove bolt #60 ? This bolt passes thru a groove in the shifter rod and must be completely removed rather than just loosened.
 
Good call Dave, that is the caution I was going to add. Most students don't take it all the way out wreck it. Is it loose and just won't come all the way or not moving?
 
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Yes, I did remove the screw completely......I did a google search and found that there is a horizontal pin that runs through the top of the drive shaft that must be lined up with the grooves in order to allow shaft to drop out. I turned the shaft a bit and presto.....lower end was free.

My impeller appears to be in great condition, but I'll change it just in case it's worn. I also pulled the thermostat, mostly to check for any grime in the water lines coming to and from it. I dropped thermostat in hot water (140-180 degrees per thermometer) and it did NOTHING. Guess I'll order one of those as well!!

Thanks again for all the help, if you can think of anything else I should check, let me know!
 
I change my impeller every 2 years. When a motor sits, the impeller takes a set and will not pump very well. Its cheap insurance. Congratulations on getting a good deal on that motor.

Dave
 
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