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1972 Seaswirl Electric Shift 120 hp-Questions on the electric shfit lower

gharvey

New member
I have done the following diagnosis:
1) checked voltage from power to shift switch 11.83 volts, the purple wire
2) I have checked to voltage from both the green wire and blue wire from the switch out. 12 volts and is continuous through the range of the switch. No voltage when the switch is in the middle position.
3) Checked to voltage at the intermediate both green wire and blue wire separated from the lower at the knife connections. Voltage 11.8 something.
4) resistance from either wire to through the lower wire, 5.9 ohms. This is within spec.

Started the boat, ran at about 650 rpm. Moved the throttle handle to forward position. No forward engagement. Trouble light shows voltage. When I looked at the prop while engaged, the prop was actually moving. I took a broomstick and could hold the prop back. I get no forward or reverse from the lower and don't hear any engagement.

I would find it difficult to believe both spring tangs are broken. It looks like I may have to pull the lower and ope it up. Does anyone have any possible ideas of what is could be. I am wondering if something got jammed maybe which allow the prop to turn in neutral. I know from all the reading I have done that these drives have a low opinion but it is what I have and I actually enjoy the boat. I rebuilt the upper and the intermediate so why not. I would just like to know some of the possible reasons for this.

Thanks for all of you help.....
 
Check splines on the waterpump shaft / upper shaft coming out of upper gear box?---Splines on intermediate shaft and engine coupling ?
 
I will check again tomorrow. I am certain that the splines in the upper to intermediate are OK. The water pump splines are OK too as the shaft as I remember will not turn which means the splines are holding to the upper drive shaft, however, I am not sure about the female end to the lower male end splines.

The question I would still have is even if the splines in the water pump impeller to lower drive shaft are suspect why would the reverse/forward gear not sound like they are engaging.

After I remove the lower, then I could remove the impeller and try the splines on the lower drive shaft and try and turn the impeller shaft with a vice-grip to see if the slip, correct. If anything was wrong in the spline area I might think it would be the lower drive shaft splines as the impeller shaft was replaced about two years ago when the splines to the upper portion of the impeller when out. I know the sound the sound of that one and you lose all power. This brings me to another question: If the impeller splines were suspect then the engine would overheat wouldn't it. It runs at 160 after it warms up and seems to be staedy at around 750 rpm.

Thanks so much for your help. We'll get this dog figured out. Should go ahead and pull the lower tomorrow ? Seems like it will need to be done !
 
I just couldn't wait so I pulled the lower. The water pump seems that it cannot be moved so I am doubting splines at this point. I do have another question though: When I use water through the hose to keep the engine cool, does that mean the impeller is also involved with running water to the water pump in the engine. If this is true then I don't think the water pump shaft splines are not holding. Is that true ?

I will probably take the leg off the lower in the morning and see what else I can see.

Respectfully:cool:
 
Ok next steps
Took leg off as well as the bottom water trim piece
Removed the swing assembly it will need new seals, may need a shaft. Not completely sure of the spline and of course there is some scoring. No water it seems. Pulled the magnets. Not in my opinion, too much debri. now the magnet wires are completely exposed. No shorts no cuts. They both read 5.9 ohms. So resistance seems to be in spec. When I apply 12 volts to either one of them i do not hear any clicking. I did drain the oil completely as well. You would think I could hear them click on the gears. I checked the battery I was using 12 volts.

Could both magnets have gone bad ? I find that hard to believe ! Could something else be interfering. I was thinking about flushing out the lower with something, not sure what to use. If I don't have to take out the prop shaft that would be nice. I may go ahead and pull the drive shaft. I don't tink I need to pull the prop shaft to get it out.

Any suggestions ! I am running out of ideas.
 
No you will not hear clicking when applying 12 volts to the wires.--With oil in there the wrap springs usually engage without any sound.---Wel if you put a stethoscope on there you might detect something.---With 12 volts applied does the propshaft lock up in one direction and turn with some drag in the other direction?------Those lower units are actually very well built and reliable.---Have a few used ones on hand.----Note---- the propshaft must be removed in order to pull the lower driveshaft.
 
I think you are very correct. I am going to try applying voltage to the forward coil. Then see if I can turn the prop shaft while holding the drive shaft. I was actually reading about doing this from another site in Canada. It might be that BOTH clutch springs are broken. Wow,this could be costly. I don't understand how both could go out. I have people say they can hear the energized magnets clicking. I do also find this hard to believe. There is a company in Canada T. C. Electronics that is very good with OMC. Apparently they have had good luck fixing these springs as they are expensive. I think the tang breaks off.

I did finally notice that there is a nut the holds the pinion gear onto the lower drive shaft that has to be removed before I can completely pull the prop shaft out. I is apparently some what tough to do. I thing I will go ahead and pull out the prop shaft cover and see if I can get the coil and spring/gear casing out. Then I can see if the spring is broken which I really suspect is the case. I might call T.C. Electronics and see what they would charge to rebuild the prop shaft with the parts I have that are good. Know anyone who has fixed these clutch springs ? I know I have gotten myself in a jam with this stringer but I am almost through it as I have rebuilt the top end already and the engine appears to be in good shape. I enjoy doing this stuff it is just way expensive for me. Anyway thanks for your response. I have a manual and I do try to read and understand before I leap or ask to many dumb questions.
 
Where in Canada are you ?-----A good used lower unit may be an option for you.-----I have replaced springs but never repaired the tang on one.
 
not in Canada. In Merced California. Just had a valuable experience though, shows why experience is so important. I removed the prop gear head. I then decided foolishly to try your idea. I hooked up the power and then held the lower drive shaft while trying the prop shaft. Zorch, the dogon coil moved because it wasn't bolted to the gear prop seal and must have shorted. I yanked the wires from the battery. Let is cool and did a continuity test. Still 5.9 ohms, I hope I didn't **** up that reverse coil. Idiotic no experience mistake. So now i am just going to get a pair of tru-arc pliers. The ones I have are not heavy duty enough to pull out the snap on the over the reverse coil. I can then remove the reverse assembly see what I have. I really think it is the clutch springs. i will let you know tomorrow hopefully what I find out. I have to work a little while in the afternoon so I will hopefully have time in the morning. What does a lower cost these days?
 
Ok sorry for not responding in so long, like everyone else been busy. So I have removed the prop shaft as well as the lower drive shaft. The tabs on both coil springs are sheared off. It looks as if someone tried to weld on of them. So now at what looks like an expensive price I have to et forward and reverse coiul springs. The magnets seems to be working fine. The ohm value is in specs and they do magnetize when power is applied. I till don't see how the damn things works. Could someone help to understand it. It seems that the reverse and forward are always in contact with the pinion gear on the drive shaft. When power is applied the magnets pull on something which I guess winds the spring tight which keeps the tension taught allowing the gear to run the prop shaft. I just don't see how it looks. Anyway, making progress. The lower looks in really good shape as well. No water believe it or not. I hope to get it running soon after I figure out how to get some money to buy the damn springs, seals,and hex screws.
 
Like all outboards and sterndrives the gears are always meshed.----And on yours the magnets pull on the springs.----The spring then wrap tight on the drums to turn the propshaft.-----Try e-bay for some springs.
 
I know where there are a bunch of these gearcases laying at a boat wrecker.----May investigate what they want for them " as is " must be good spring in em.
 
Well I am really really long in replying about my lower problem. The fact is that I couldn't get to it until just recently. The good news is the boat is now running. I finished the lower with new coil springs, reverse and forward along with seals. It seems to work on the trailer and I have a better understanding of how this works. So appreciate all of the help I get from this forum too. I will be starting another thread about the Rochester 2bbl carb as I need some insight into all of that now. Yippee I will be out on the water soon.
 
Check to make sure your shift switch is okay. If that unit is put in BOTH forward and reverse at the same time, you can break the tabs off the springs.
 
I know, OMC electric shift stern drives are “long in the tooth,” so to speak but since I can find a variety stern drive parts cheap [such as a collection of 4 upper and lower housings for $200 once] I will stick with it a while longer.
Running these older versions in salt water can be problematic. However, the water pump housing can be, upgraded to stainless steel. Again, I have 3 S.S. housings now, which I bought cheap. The impellers are huge and any overheating is non-existent. With a 120 hp 4 cyl engine, the manifold is easy to convert to fresh water. The trick is to add a small Honda Civic car header into the circuit and fabricate a stainless high-rise elbow. Now as great as all these modifications are I still have a weak link in the drive train. It seems that the upper vertical drive shaft splines corrode and strip out. This process also takes out the splines on the middle impeller shaft. And it happens every 5 to 10 years depending on engine H.P. They are notorious for this flaw and it is probably their only downfall.
In any case, something I have noticed is how the lower splines of the middle shaft show no signs of wear. Therefore, if the upper shaft were ever made of the same material as the middle shaft then these electric shift units would/could [on the lower H.P. engines] most likely last 20 – 30 years or more. I am currently trying to locate a machine shop capable of making a stainless upper shaft, [so far no luck]. I am also in the process of having a machine shop rework an old and damaged pump shaft. By adding a collar and cutting in new upper gear splines it just might work. If anyone else shares this same problem and shares, the same desire for creating a better stern drive overall then drop me a line. Perhaps we can achieve this goal cheaper and easier.
 
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