I guess I should have known better. I saw a 20hp Model 200 Outboard on Ebay that was relatively close to where I live. It was listed by a marine dealer as having good compression, and turned over easily but had no spark. OK, big deal, no spark. Apparently the dealership had taken this motor, a 1972 model in on trade. The guy that sold me the motor said that it had been sitting in the guys basement for thirty years. I picked it up for $300 bucks. I was pretty amazed at how good the motor looked under the bonnet, except for the wiring, which basically crumbled when you touched it. I figured big deal, whats there to replace the wiring. So I took her home and replaced all the wiring, and the points (CDI Type II Ignition) and lo and behold I have Spark. Not Great Spark, but Spark.
Then I figure, now to pull the lower unit and change out the impeller, start her up and gloat. Yeah right. Aparently the owner of this motor never heard of, or considered changing the impeller, and so for the first ten years of its existence the lower unit was never pulled. Mercury, in their infinite wisdom, or their bean counters infinite wisdom, made their driveshafts out of regular ole carbon steel. I have read every happy ending story on the web hearing how people have been sucessful at extracting their driveshafts from their powerheads after a little sweat and tears.
I tried everything, but to this day, I have never been able to get the damn driveshaft spline to pull out of the crankshaft. After about two weeks of trying with everything under the sun, I finally ended up cutting the driveshaft by cutting a hole with a hole saw through one of the lower motor mount wells after getting the rubber mounting pucks out of the holes under the medalions. These are held in with steel lock rings. Another misuse of materials subject to a corrosive environment. (Thanks again Mercury) I had to drill several holes through the shaft to cut it.
Once I did that, I was able to remove the lower unit and take the water pump apart. Holy crap. The driveshaft was so corroded that I had to put it on the lathe to clean it up, then I sleeved the water pump area with a 6 inch brass nipple that I turned to size with my trusty old 1942 South Bend Lathe. I then turned a coupling out of brass, and drilled and threaded the coupling to take several set screws to bear on a flat spot I milled in what was left of the shaft. This worked for a couple of outings, then I heard the motor spin up like the prop had come out of the water. I was always worried about the adequacy of the method I used, and for good reason it turns out.
Well yesterday I found a new driveshaft on Ebay for a decnt price, and so I decided to have another go at that shaft. SInce I have the coupling brazed to the upper part of the shaft, I figured I would insert a piece of 1/2 inch ACME threaded rod into the lower end of the coupling to make a puller. I figured this time I was going to get that sucker out. I tried three set screws into the threads, no good. Then I drilled right through the threaded rod and the coupling and installed a tension pin. Cranked down on the puller. POW, the threaded rod broke. Yes, I inverted the PH and squirted penetrating oil in the DS spline end. I have used PB Blaster, Liquid wrench, I have used heat, Today I used ATF and Acetone, touted as being better than anything commercially available. I will probably try Kroil next.
I have to admit, this is one really tough nut to crack, and I have cracked my share, being 67 and a decent mechanic that has been at it since about 12 years old.
I guess the moral to this story is: I dont care if your tattle-tale is tattling away, you have GOT to pull that lower unit on a regular basis and smear it with anti-seize on reassembly if you do not want to end up with the mess I have. I am sure that the newer drive shafts must now be stainless steel, but I would never buy another used outboard without pulling the lower unit first. Especially a Mercury. The author of that little book about collecting old outboards was right.
Elmer Carl Kiekhaefer was a Lunatic. He sure wasent an engineer, judging by all the non standard sizes and idiotic methods he used to assemble these motors. Now I know why Dad preferred Evinrudes and Johnsons
Then I figure, now to pull the lower unit and change out the impeller, start her up and gloat. Yeah right. Aparently the owner of this motor never heard of, or considered changing the impeller, and so for the first ten years of its existence the lower unit was never pulled. Mercury, in their infinite wisdom, or their bean counters infinite wisdom, made their driveshafts out of regular ole carbon steel. I have read every happy ending story on the web hearing how people have been sucessful at extracting their driveshafts from their powerheads after a little sweat and tears.
I tried everything, but to this day, I have never been able to get the damn driveshaft spline to pull out of the crankshaft. After about two weeks of trying with everything under the sun, I finally ended up cutting the driveshaft by cutting a hole with a hole saw through one of the lower motor mount wells after getting the rubber mounting pucks out of the holes under the medalions. These are held in with steel lock rings. Another misuse of materials subject to a corrosive environment. (Thanks again Mercury) I had to drill several holes through the shaft to cut it.
Once I did that, I was able to remove the lower unit and take the water pump apart. Holy crap. The driveshaft was so corroded that I had to put it on the lathe to clean it up, then I sleeved the water pump area with a 6 inch brass nipple that I turned to size with my trusty old 1942 South Bend Lathe. I then turned a coupling out of brass, and drilled and threaded the coupling to take several set screws to bear on a flat spot I milled in what was left of the shaft. This worked for a couple of outings, then I heard the motor spin up like the prop had come out of the water. I was always worried about the adequacy of the method I used, and for good reason it turns out.
Well yesterday I found a new driveshaft on Ebay for a decnt price, and so I decided to have another go at that shaft. SInce I have the coupling brazed to the upper part of the shaft, I figured I would insert a piece of 1/2 inch ACME threaded rod into the lower end of the coupling to make a puller. I figured this time I was going to get that sucker out. I tried three set screws into the threads, no good. Then I drilled right through the threaded rod and the coupling and installed a tension pin. Cranked down on the puller. POW, the threaded rod broke. Yes, I inverted the PH and squirted penetrating oil in the DS spline end. I have used PB Blaster, Liquid wrench, I have used heat, Today I used ATF and Acetone, touted as being better than anything commercially available. I will probably try Kroil next.
I have to admit, this is one really tough nut to crack, and I have cracked my share, being 67 and a decent mechanic that has been at it since about 12 years old.
I guess the moral to this story is: I dont care if your tattle-tale is tattling away, you have GOT to pull that lower unit on a regular basis and smear it with anti-seize on reassembly if you do not want to end up with the mess I have. I am sure that the newer drive shafts must now be stainless steel, but I would never buy another used outboard without pulling the lower unit first. Especially a Mercury. The author of that little book about collecting old outboards was right.
Elmer Carl Kiekhaefer was a Lunatic. He sure wasent an engineer, judging by all the non standard sizes and idiotic methods he used to assemble these motors. Now I know why Dad preferred Evinrudes and Johnsons
