Evinrude 4hp frozen solid

Shayneh2006

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Oct 19, 2020
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Hi there from down under..... So I have a long shaft Evinrude 4hp that was given to me from grandpa to father to me. Since it has been on the back of my boat, I often start and run it from time to time just to give piece of mind that it works and will get me out of trouble should the 35hp let me down. It is always started and operated in fresh water. So the other day, I thought I would crank it over and idle it for a few minutes but not to be, it’s not moving a budge when the pull starter is operated..... After some research online, decided to start my elimination at the lower leg, and this is where I have come to a grinding halt....My plan was to remove it and determine if the gearbox was seized before moving further if not..... The problem is, I can get one bolt out but the other is solid frozen.... I have tried everything by knocking the head of the bolt with a drift and squirting WD40 up the exhaust port...... I definitely don’t want to put too much torque on the bolt and snap it leaving a further problem..... Suggestions appreciated
 

Shayneh2006

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Some photos
 

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Crosbyman

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with no access the threaded area inside the lower housing try heating the bolt
head. maybe the expansion can break the bond
alternatively you could try freezing the bolt head ...a can of keyboard cleaner spray held upside down will freeze it

the use of a 1/4 inch impact wrench with short burst may help (try a few shots in both directions to break the bond )

one method is to grind off the bolt head allowing you to release the gearcase and give you access to the remaining stud and possibly access to the thread area which you can soak with a release agent this will also give a closer access the the frame which you can heat up and soak.

"patience brings joy" said the fortune cookie :)
 

racerone

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Grind the head off that bolt.-----Lower unit then should come off.-----Use heat on the housing to then remove the rest of the bolt with vise grip.
 

Shayneh2006

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Thanks for the replies..... Whilst sorting through a box of parts that came from the grandpa I have found components of an extension kit that appears to be the same as the one in question. That said, I now have a better understanding of what I am dealing with and think it is possible that the motor could be locked up due to the main drive shaft rusted and frozen in the extension bushing. First as discussed, I need to seperate the lower unit to see what’s happening inside..... Thanks for the advice. Grinding the head off the bolt will be last resort and at least now I have two new replacement bolts in this recent kit I have found..... I assume the bolt is frozen into the main exhaust housing so before I start cutting into to bolt, want to assess whether I can get some penetration oil up there somehow..... Any suggestions
 

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Crosbyman

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if you snap the bolt you may have nothing to grab and soaking won't help much

then you will be into drilling and tapping 😱
 

Shayneh2006

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Ok, I decided to cut the head off the bolt but too my amazement, the lower unit will still not seperate from the extension/exhaust housing. I tried a slide hammer and gently tried to pursued the lower unit away but to no avail...... I can understand if the drive shaft is corroded and fused into the upper motor but surely the lower unit should seperate from the drive shaft.... I did one final check of assessing the condition of the gear oil within the lower unit (to make sure no water or corrosion) and it appears to be clean, Not sure what next to do 😢
 

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Grub54891

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Looks like you ground the bolt, but it is recessed in the housing I think. You may have to dremmel the rest of the head off or drill it to remove the head of the bolt.
 

Sea Rider

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Have you previously troubleshooted the no go on the powerhead... If not, put lever to neutral. Remove the starter assembly. remove plug, put a wrench on the upper flywheel nut and turn it slowly CW, if doesn't turn, rise motor fully horizontal and squirt/spry a good amount of a mixture of 10:1 fuel/oil or Power Tuner carbon remover or WD-40 over the piston's head, let soak to penetrate for some hours, rotate flywheel CW-CCW slowly with wrench till the piston rotates freely again. Most times when having a piston seizure the rope will be very hard to pull...

Happy Boating
 

Crosbyman

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if the shaft is stuck in the PH....I would drill a small 1/8 hole in line with the drive shaft just below the PH and spray in some PB blaster or similar product inside and let it drain down to the upside down PH you can plug the hole later with a touch paint . Dollar stores havea wide variety of nail polish colors some very close to what you need for touch-ups
 
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Shayneh2006

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Again thanks for the replies and help. @ Sea Rider..... I did remove the spark plugs and lifted the outboard to a horizontal position and sprayed plenty of WD40 into the combustion chamber (prob not the best product out there to do it) and let soak. With the outboard put back into vertical position, found the WD 40 egressing out of the lower exhaust. The outboard is direct drive, no forward/reverse....
 

Shayneh2006

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@ Crosbyman..... It’s confirmed the drive shaft if frozen in the PH..... This morning before work, I hit the work shed and with a block of wood and hammer, separated the extension housing from the exhaust housing by knocking the extension housing sideways. Understanding that I still have a bolt running through and conneacting all three components, used the bolt as a pivot point. Once loosened. Was able to easily move the extension housing sideways back and forth from day 11 o’clock to 1 o’clock..... I noticed the flywheel moving as well.... So that said, the cause of the original problem (engine frozen) was caused by the drive shaft frozen to the extension housing bushing...... To sort this out, I must free the drive shaft from the power head so good suggestion on drilling a hole and getting some penatrstion oil to help unfreeze
 

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Crosbyman

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if you have access to the drive shaft no need to drill just send down some juice to the upside down PH and wait then resoak after a few days

I like clear silicone spays they are clear like water and seem to have better capilary qualities to enter stuck boltsand all. Snowblower silicone is slippery as H... and seems to get in easier jmho
 

Shayneh2006

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if you have access to the drive shaft no need to drill just send down some juice to the upside down PH and wait then resoak after a few days

I like clear silicone spays they are clear like water and seem to have better capilary qualities to enter stuck boltsand all. Snowblower silicone is slippery as H... and seems to get in easier jmho
Thanks for the advice and yes, I have silicone spray at home so will give it a try....
 

boobie

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Rather than the silicone spray mix up a mixture of 50% acetone and 50% ATF and try that.
 

Shayneh2006

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Thanks for the reply..... A lot has happened since my last post..... I got it all apart..... The drishaft was not frozen to the power head. It was frozen to the extension housing bushing..... Also, that bolt that I was having trouble with was also rusted in the extension housing requiring it to be drilled out. It ended up breaking inside the exhaust Housing..... Pretty crappy design by Evinrude
 

Scott Danforth

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.... Pretty crappy design by Evinrude
not really, the motor was designed to last 15 years (yes, that is only 15 years) with minimal maintenance and be replaced...... so how old is the motor?......

and yes, with great maintenance you can get a longer service life, however the motor was still only designed to last 15 years.

BTW, a 50%/50% mix of ATF and acetone is a grey-beard mechanics go-too penetrating oil
 

DRCrowe

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May 22, 2018
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I had the same issue with a 1983 merc 5 hp. I thought it was froze up too. I hung the motor from the ceiling of my garage and made my own slide hammer wrapped around the lower unit and finally won! I reamed out the tail shaft bushing and cleaned up the shaft and it has been working like a champ ever since. I never thought I'd see anyone with the same issue! Guess it doesn't matter if its a merc or Evinrude. Good luck! Its worth it! Plus you learned a bunch in the process!
 
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