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jo hall

J

jo hall

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I've been advised to replace the 30 year old impeller in my 1981 Johnson 70 hp. In fact more than one johnson mechanic has told me OMC recommends doing so every year. I have removed the 5 bolts that secure the lower unit to the exhaust housing and still it (lower unit) refuses to budge. It's as if there's still a bolt holding it in place. I know that the shifting linkage will need to be disconnected but from what I read on similar threads the gear case should drop about an inch even with that linkage still connected. What am I overlooking?

Also it looks like the shift linkage connection is just below the intake manifold with not enough room to work to get it disconnected. Looks like the power head would have to be removed first and don't see how that could be done before disconnecting that linkage. Again, what am I missing? I know, a repair manual. Got one on order but fishing season is just around the corner and I need to get this rig back in operation.

Would appreciate any and all help!

JO Hall
 
There are 6 bolts to remove ----------one is hidden under the trim tab --------Consider yourself lucky with a 30 year old impeller.------------Mechanics get blisters on their tongues trying to get people to do maintenance !!!
 
As for shift linkage, remove the bolt/screw going in from PORT side through the vertical shift rod. Hopefully you may get it out after all these years. If stuck, remove the carb above, be sure no fuel in the vicinity and heat the connector. If you break off the screw head, you may be in bigger trouble than you want to be!!
 
racerone said:
There are 6 bolts to remove ----------one is hidden under the trim tab --------Consider yourself lucky with a 30 year old impeller.------------Mechanics get blisters on their tongues trying to get people to do maintenance !!!
Click to expand...

Thank you racerone.......didn't occur to me they'd hide one under there! Actually I guess it did, just didn't think they would. Thanks again. BTW, I finally got the high speed jets out and found that two were 52d and the third was 56d which maybe could explain some of my high altitude problems. Best I could find locally was a set of 50d's so will try those first and if necessary order one step smaller to try.
 
All the parts lists I have found seem to list only the original (sea level I assume) jets. I do most of my fishing at 8500 to 9000 feet and only occassionally at around 4500 feet.
 
Factory service manuals ( 90's models ) have part #'s for a wide range of jets.------------Jets have basically been the same design from the early 1960's to the late 1990's.
 
Once I removed bolt #6, and decoupled the shift rod she slid right out. ................can anyone tell me why they added the nylon wedge gizmo to the impeller/key assembly?
 
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