Topic: 1959 Sportwin Powerhead noise – Antique Outboard Motor Club,Inc

This topic has 9 replies, 5 voices, and was last updated 3 years, 4 months ago by fleetwin.

Viewing 10 posts - 1 through 10 (of 10 total)

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June 18, 2021 at 9:07 pm #240561
bob-d
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US Member
Hi all, just started a new to me 10 Hp 59 Evinrude Sportwin in my test tank for the first time. There was a distinct metallic knocking noise in foward under load, that went away at low revs in neutral.
Used the rubber hose method to try and pin point where the sound was coming from, it seemed to be the middle of the crankcase. I was thinking piston slap, but head area was quiet.
Compression is 75/70. Pushed a screwdriver against the pistons and no movement.
Ideas.
Thanks,
Bob D
June 19, 2021 at 12:42 am #240567
frankr
Participant
US Member
bob-d wrote:

Hi all, just started a new to me 10 Hp 59 Evinrude Sportwin in my test tank for the first time. There was a distinct metallic knocking noise in foward under load, that went away at low revs in neutral.
Used the rubber hose method to try and pin point where the sound was coming from, it seemed to be the middle of the crankcase. I was thinking piston slap, but head area was quiet.
Compression is 75/70. Pushed a screwdriver against the pistons and no movement.
Ideas.
Thanks,
Bob D

I was ready to pounce on the classic 10hp clatter until I read your last sentence. Those motors are famous for beating the wrist pins loose in the pistons. The usual diagnosis is to follow the piston half-way down on it’s downward stroke with a screwdriver, stop turning and give the piston a push with the screwdriver. The looseness will show up as a clunk. The cure is pistons, rods, and wrist pins from a 1961-63 10hp.
June 19, 2021 at 10:14 am #240604
bob-d
Participant
US Member
Yea Frank, I read all your old posts and that’s what I was hoping for too, at least a definitive answer before I open her up.
Another thing I thought of since the noise is localized in the middle of the powerhead, was possibly where the driveshaft meets the crank is worn, but then why wouldn’t it make noise at idle. It’s a weird metallic chatter , not clunking.
Well since I most likely will have to open it up, I’ll probably end up going to do the 61-63 upgrade since I’m in there already.
Thanks,
Bob D
June 19, 2021 at 12:05 pm #240611
Mumbles
Participant
The ’59 rods have slightly wider bushings in them than previous years and was probably an attempt to cure the wear problem which the earlier motors suffered. If you don’t want to swap them out for the needle bearing 61-63 rods and pistons, the small end bushings can be replaced but you’ll have to fabricate them yourself.
- This reply was modified 3 years, 4 months ago by Mumbles.
- This reply was modified 3 years, 4 months ago by Mumbles.
June 19, 2021 at 12:40 pm #240624
bob-d
Participant
US Member
Thanks Jim, I also saw that on one of your previous posts. Unfortunately fabrication is a bit above my pay grade .
Hey if I’m at this point I mind as well build the big rod stroker motor. Ha ha
I have to admit from your picture of the rods the 61-63 setup is certainly an upgrade from the 59.
Thanks,
Bob D
June 19, 2021 at 7:33 pm #240681
fleetwin
Participant
US Member - 2 Years
Hmmm…Seems like you have checked for sloppy wrist pins and ruled that out. Could be a damaged upper or lower crank bearing, but perhaps the gearcase is making a racket, sometimes those noises travel upward…Have you drained and inspected the gear lube? You could try removing the gearcase, then putting the engine back in a barrel and starting it to see if it still makes the noise…
June 19, 2021 at 11:24 pm #240701
bob-d
Participant
US Member
Don, a good point regarding the gear case. I definitely will try that before I tear into the head, although I did listen to the exhaust housing with my rubber hose while the engine was running, and it was quiet.
Before I started the motor for the 1st time I did put new seals, and a new clutch dog in the gearcase. The gears and shaft looked ok.I also changed out the impeller and associated seals and o rings.
Unfortunately I can’t dig into the motor for a few weeks because of travel, but I will definitely keep everyone updated once I find the culprit.
Thanks,
Bob D
June 20, 2021 at 8:25 am #240713
fleetwin
Participant
US Member - 2 Years
I wish you could post a video of the engine running making the noise…But, audio is usually deceiving. OK, you had the gearcase apart, so am thinking we can kind of rule of issues there. The only other area that should be looked into is perhaps something under the flywheel is loose and chattering around. Could be the recoil as well. I just don’t want to see you pull the powerhead apart needlessly.
June 24, 2021 at 12:09 pm #241140
russ
Participant
I have a 1958 10hp Evinrude that sounded like you are describing. Too recoil assemblyk recoil off and found a shinny spot on top of the inspection plate of the fly wheel.My cure was to put a washer under each of posts that the recoil screws to.No more noise ar any speed. Just a thought…Russ…
June 24, 2021 at 4:34 pm #241157
fleetwin
Participant
US Member - 2 Years
russ wrote:

I have a 1958 10hp Evinrude that sounded like you are describing. Too recoil assemblyk recoil off and found a shinny spot on top of the inspection plate of the fly wheel.My cure was to put a washer under each of posts that the recoil screws to.No more noise ar any speed. Just a thought…Russ…

A good thought indeed…Perhaps remove the recoil and pull it over with a rope on the flywheel…Perhaps something is loose/clattering around under the flywheel also…
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