Topic: 1953 Evinrude bigtwin problem – Antique Outboard Motor Club,Inc

This topic has 7 replies, 6 voices, and was last updated 6 years, 10 months ago by makeitrun.

Viewing 8 posts - 1 through 8 (of 8 total)

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June 22, 2017 at 3:30 am #7394
makeitrun
Participant
I’m not sure why this is happening while running my 53 bigtwin I noticed it making a clattering noise from mid to full throttle. I decided to pull the flywheel and have a look and noticed small metal shavings everywhere. I pulled the magneto cam and noticed the outer seal spring retaining washer had cut away at least 1/8 inch off the bottom of the magneto cam. I’m thinking the spring and upper and lower spring retaining washers spins with the magneto cam right? Why is this happening.
June 22, 2017 at 10:46 am #60118
david-bartlett
Participant
Joe,

I am by no means an expert on these, but you are correct that all those pieces should rotate together. Somehow it seems that the spring is not turning at the same speed as the cam, allowing the hardened seat to wear into the bottom of the cam. Possibly the bottom seat of the spring is hanging up on the casting above the top seal??

You probably already figured this out anyway.
June 22, 2017 at 4:20 pm #60133
olcah
Participant
US Member
Look at a parts breakdown. There should be a hard carbon seal below the spring. Look at the top of the bearing and be sure that surface has not been damaged as that is the seal area where the carbon bears. Hope this helps.
June 23, 2017 at 12:19 pm #60175
1946zephyr
Participant
Something inside might be stopping the spring, while everything else rotates. Very strange. Never seen this happen before
June 25, 2017 at 2:36 am #60270
garry-in-michigan
Participant
Lifetime Member
If the carbon seal is damaged or missing The spring can catch on the casting. Then the cam rotates and the spring doesn’t. As noted, the carbon seal MUST have a smooth surface to seal against. . .
June 26, 2017 at 1:53 am #60355
makeitrun
Participant
I Checked the carbon seal, all looks good I can’t see anything to keep the spring from not spinning.
June 26, 2017 at 2:57 am #60362
jeff-register
Participant
US Member - 2 Years
Where is the wear pattern lay? That’s the key.
July 3, 2017 at 5:12 am #60876
makeitrun
Participant
quote Jeff Register:

Where is the wear pattern lay? That’s the key.

On the outer seal spring retaining washer
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