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Lower Unit Stuck

C

ClearBlue

New member
Just bought a 1957 Evinrude Lightwin 3hp. I wanted to check the water pump, took off the 4 bolts and tried to pull off the lower unit but seems the lower unit shaft is stuck to the crankshaft. From what I have researched the two are joined by splines and there are no pins, etc. I tried (lightly) plying but no luck. I thought about trying to pull it apart with some straps and pipe clamps (make shift come-a-long) but afraid I'll damage something. At this point I'm considering bolting it back and just hoping the impeller is OK and move on to the carb and magneto rebuild. I haven't run the motor so don't know if the pump works or not, it def needs carb and ignition work to get it running. Thought impeller replacement was a good first step. Any advice would be greatly appreciated.
 
Welcome. Try putting motor upside down on the floor and squirt some rustblaster in so it runs down into the splines. Maybe do this while your cleaning carb and fuel tank....as those parts will be on your work bench.
 
Almost classic.-----There have been many of these motors scrapped because of rusted out splines in the carbon steel crankshaft.-----Sometimes hard to explain to a novice to do a complete evaluation before spending money on parts.-----It might run for 10 years or 10 minutes with rusted / damaged splines or no cooling water!
 
Appreciate your reply timguy. I just spayed 1/2 can of WD-40 onto the shaft with the motor turned upside down. Maybe that will loosen it. I'll let you know.
 
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Thanks racerone. I'm def a novice. Picked this model motor as a project after reading that its pretty easy to work on and parts are available. Good advice to do a complete evaluation before spending money on rebuilding carb and magneto. Sounds like what timguy told me is my best bet. If I can't get it off with some penetrating oil I think I'll clean up the carb and plugs and try to start it. If it pumps water probably then rebuild the carb and magneto and hope for the 10 years. Worse case I have a parts motor and I'll roll the dice on another when one comes up on eBay.
 
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I let the WD-40 soak a while, stepped on the fuel tank mounting plate / handle and gave a good yank (maybe too good in hind sight). The drive shaft pulled out from the gearcase, the impeller pin chipped the impeller housing as it slid past. The pics are the housing. I might be completely crazy but I'm pretty sure I can get put this back together without freeing the driveshaft from the crankshaft. The housing isn't cracked, I think I can put the impeller in the housing with the chip in line with the impeller slot, attach the housing and slide the assembly onto the crankshaft. From what I can tell the inner rubber part of the impeller seals to the top of the housing on one side and the wear plate on the other. I don't think the size of the chip will prevent it from sealing. I'll file the edges a bit so it won't wear on the rubber. The downside is that it might be difficult to get the gearcase off in the future to service the water pump. I'm not giving up on this!
 
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Exactly what happens when driveshaft sticks in the crankshaft.----Make an adapter and use slide hammer to pull driveshaft out.
 
racerone said:
Exactly what happens when driveshaft sticks in the crankshaft.----Make an adapter and use slide hammer to pull driveshaft out.
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Great idea! I think I can use a little JB Weld to sure up the housing and put the lower unit back together in a more conventional way (less hair-brained) than I described in my post above.
 
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timguy said:
So what did the impeller look like was it shot?
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Before cleaning / after cleaning. No experience with these things but the wear plate is scored pretty badly. The impeller isn't bad, its not brittle, but there is def some wear. Still leaning toward leaving the drive shaft attached to the crank shaft and reassembling from the bottom up. I mean the two are obviously connected well which can't be a bad thing. I can't see the downside of making the chip that I broke out of the impeller housing a nice clean keyway, take a round file to it. Then the impeller pin will slide into the housing and set on the impeller when I slide the gear housing on. A little unorthodox I guess. Pretty sure it won't leak water into the housing above it. I mean the way its designed the crank shaft comes thru the impeller housing with no seal. Looks like the impeller itself forms the seal between it the two surfaces: top of the housing and wear plate. I think at this point I'm going to take racerone's advice and evaluate everything so I know if its worth spending the $ to make the repairs. Think I'll shift gears and try to get the motor to start.
 
Good thinking. I know you are a wise thinker. That scoring is normal on the pump plate.....impeller looks decent. No cracks, right? I have put them together just the way you describe when I've run into really badly stuck driveshafts. Make sure impeller is set with fingers in correct orientation......turning impeller clockwise looking from the top. This is going to be a sweet little motor if you can pull this off. Racers been around forever, so his advice is usually golden. He, as well as Joe, Pappy, Gator, Boobie, Chris, Rick, Bondo, Galamb, o2...........and many other techs here, have long been my mentors.....it's partially because of them, that I operate a profitable home based marine repair business.....and the advice is free with no obligation. If I ever get to meet these guys, I'm gonna bring em a 30 pack of "REAL BEER",.....not that "pu$$y stuff".......gonna bring em a HAMMS.
 
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I become think that if it would be possible to take whole powerhead away from the middle section? Then you and work with driveshaft on your table. These 3hp, driveshaft can only put back to gearcase with gearcase upside down, then push the driveshaft inside and turn the shaft while you push it inside. Here i have couple of photos about the middle section and powerhead connection. I took these photos during my rebuild project. Be sure you have new gaskets before doing anything.

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2.jpg

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It was really hard to clean everything old gasket-material / dirt away
 
Good photos, Evinrudeman. I remember you had to get your gaskets fabricated. That motor is saltwater too, but so important to see that o-ring at the driveshaft splines. Right, maybe Blue should remove powerhead to access the shaft where it's rusted into the crankshaft, so he can address the problem directly. Blue, have you done a compression test to see what your working with? You can remove the exhaust cover there on the port side of the powerhead....if the screws arn't rusty. Then you can look at the rings and pistons to see what you got.
 
Yes some gaskets i needed order from "gasket-tailor", but all the gaskets which belong to between powerhead and middle section, i got from the Evinrude dealer without problem. Yes i think it is best option to remove the powerhead from the middle section, then it is easy to work with driveshaft. One option is also, to buy another 3hp for parts, and take crankshaft + driveshaft from that engine. For me another engine for parts costs only about 25 USD.
 
timguy said:
Good thinking. I know you are a wise thinker. That scoring is normal on the pump plate.....impeller looks decent. No cracks, right? I have put them together just the way you describe when I've run into really badly stuck driveshafts. Make sure impeller is set with fingers in correct orientation......turning impeller clockwise looking from the top. This is going to be a sweet little motor if you can pull this off. Racers been around forever, so his advice is usually golden. He, as well as Joe, Pappy, Gator, Boobie, Chris, Rick, Bondo, Galamb, o2...........and many other techs here, have long been my mentors.....it's partially because of them, that I operate a profitable home based marine repair business.....and the advice is free with no obligation. If I ever get to meet these guys, I'm gonna bring em a 30 pack of "REAL BEER",.....not that "pu$$y stuff".......gonna bring em a HAMMS.
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I've heard of Hamms beer but haven't seen it here in Virginia. I like the micro-brews round here, not sure if that is pu$$y beer, lol. Good to hear that people on the forum are so willing to help, I see that already. I def need the help and appreciate y'all. I grew up in Maine and we had tractors, chainsaws and such, so I have just enough knowledge to get me in trouble. Yeah this is going to be a nice motor with some time. Its going on my 11' kayak, a real wide stable little boat. I have a minkota on it now but its not enough sometimes against the current in the James River west of Richmond VA where I fish for small mouth. Goal is to have it mounted by June. If it runs good next winter I'll make it pretty. Thanks for your help!
 
Thanks for reply Evinrudemen. If I decide to go that route its good to know I can get some guidance. To be honest I'm not sure I have the skills (yet) to take on something like that. Carb rebuild, magneto rebuild, sure, this? maybe not. Hats off to you for nice work.
 
Yeah timguy really enjoyed seeing those photos. I'm really facinated how this machine is put together. As far as compression test, no, unless pulling the plugs, putting my thumb on the socket and pulling the starter counts. It was pretty sucky when I did, my thumb may not have been calibrated though. :pOn some of this I'm going to take a leap of faith. I paid $266 delivered from eBay, parts might cost another $150, if I end up with a 32 lb door stop my only regret will be having to listen to my wife bitch at me about it, lol. I'm having fun, that's what counts. Here is the ebay pic of it. It was filthyEvinrude.jpg
 
Hurry , hurry----Join the local chapter of the ---aomci------At a swap meet you can pick up 3 HP motors for about $50.------Plus you meet folks with similar interest.----Years of experience perhaps in your neighborhood.
 
racerone said:
Hurry , hurry----Join the local chapter of the ---aomci------At a swap meet you can pick up 3 HP motors for about $50.------Plus you meet folks with similar interest.----Years of experience perhaps in your neighborhood.
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Yeah I saw their website, I'm thinking about joining. Thanks!
 
I don't think they have one close to Duluth, but I'm gonna check. Buy the wife some flowers....always works. Hamm's is a top classic lager beer, full bodied and smooth. Not sweet or bitter. It's the kind of beer that when you have a real thirst you can guzzle a whole can in about 10 seconds.....and feel like you did something good.
Photos came from Evinrudeman in Finland, very crafty mechanic over there. His specialty are these "tinytwins".
 
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Thank you very much timguy. These 3hp engines are generally so simple, that there is no need any special tricks when working with these. It is easy to take these engines parts, and put them back. Nothing special is needed. Right tools, right moments, and some patience when cleaning interior parts. I always take lot of photos when doing bigger repairs, and make good notes. During disassembly it is important to put parts own boxes, and write where they come from. Some bolts may look similar, but are different length, that must be note too. Also it is good idea to clean every bolts good, all dirt must clean away from every threads because that makes bolts easy to open another time. When working with cylinders and fuel system, it is specially important to keep your hands very clean, and use only clean rags. Just few hint when working with any engine. I have become dreaming about new project maybe after covid, maybe 5hp (max) Older Evinrude.
 
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Appreciate your replies Evinrudemen. I can see how working on one projects leads to more. I'm already thinking about what I want to tackle next. Elgin motors look pretty cool.
 
Got a couple little twin cylinder Elgins here. Both will run with a little help. They seem like a nicely engineered motor.
 
I am working on a 93 9.9 Yachtwin Long Shaft. For the life of me I can't get to the lower unit to rebuild the water pump. I remove the bolts from the lower end and the spacer/adapter and the adapter won't drop but 1/16 at most. I can twist it side to side and see the shift linkage bolt. It just wont lower enough to remove it. Any ideas how to address this?
 
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