Evinrude 3hp Lightwin 3012-03700 prop seal

Agriculture

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I have what I assume to be a very early 1952 Lightwin. The serial number (03700) is the earliest I've seen. I've gotten a lot of good information from reading the other threads on the 3012 but I can't find any mention of the problem mine has.

I'm trying to replace the prop and main shaft seals (aka oil retainers) in the lower unit. According to all the literature I can find online, both seals are SUPPOSED to be p/n 300599, which is a lip seal with a 0.425" shaft size and 0.875" bore. Sierra Marine sells it as 18-2035. That p/n is correct for the main shaft seal but is TOO BIG for the prop shaft seal. The shaft dia. is correct at 0.425" but the housing is a 0.750 bore, not 0.875.

I've checked many online seal catalogs and can't find a seal with this ID/OD combination. I'm considering using a metric 10X19 seal but it's not the correct seal, obviously. Has anyone run into this before?

Thanks,
Agriculture
 

Joe Reeves

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

Does this engine bu any chance have a later model right angle drive on it instead of the regular angled weedless drive lower unit?

If so, the propshaft seal would be part number 310328 with the driveshaft seal being 300599.
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

Does this engine bu any chance have a later model right angle drive on it instead of the regular angled weedless drive lower unit?

If so, the propshaft seal would be part number 310328 with the driveshaft seal being 300599.

Thanks for the reply, Joe. To answer your question, the motor does not have the right angle drive. It has the regular, angled, weedless drive lower unit.

Do you have dimensions on the 310328? If it is a 0.425 shaft and 0.750 bore I'd be willing to try it.

I've thought about boring out the housing (bearing housing assembly) to accept the 300599 but there doesn't seem to be enough "meat" in the housing to be overbored that much without becoming too weak and cracking.
 

BillP

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

I have a 1953 JW-10 ser #1052725. Seals should be the same for yours. I completely resealed (including the prop shaft) the engine 2-3 yrs ago but can't remember if they were OMC or Sierra parts. Normally I use genuine OMC for soft parts. I think you have the right PN but the wrong part. Have you checked it against another to see if it was in the right package?

Another idea...The first yr of this OMC version was in 1952. Maybe the first few came out using prop shafts from earlier OMCs (1951 2.5hp Johnson HD-26)? I don't know what Evinrude's model was for it but it might be worth looking at for the right seal. I don't know a source for that seal but would try the aomci dot org.

bp
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

I think you have the right PN but the wrong part. Have you checked it against another to see if it was in the right package?

I bought two 300599 (Sierra 18-2035) and they are both the same. Either part will fit the drive shaft seal but NEITHER fit the prop shaft. The drive shaft housing BORE is 0.875 and my prop shaft housing bore is 0.750.

BillP said:
Another idea...The first yr of this OMC version was in 1952. Maybe the first few came out using prop shafts from earlier OMCs (1951 2.5hp Johnson HD-26)?

Since this is such an early model, this could be a possibility. I've been to several bearing houses and no one even lists a lip seal anymore with a .425 shaft and 0.750 bore.

I'm going to try a metric 10x19x7 seal and if that doesn't work then I'll have to look for a replacement lower unit.
 

Joe Reeves

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

Agriculture...... Along with my previous suggestion (seal 310328), Here's a bit of added information.

But the following may be of no use at all to you..... just something I came across today. Keeping it simple..... Are you saying that the 300599 seal's I.D. is too small for your propshaft OR that the I.D. is okay BUT the O.D. is too big/small? Somewhere along the way, it lost me.

Your engine's seal/bearing/propshaft housing's part number is 277589 and uses P/S 300599 which supersedes up to 327031, BUT this housing assembly supersedes up to part number 384714 which uses P/S seal 314167.

Seal 300599 nor 327031 connectes with seal 314167 in any way.

This leads me to believe that perhaps seal 314167 may have a larger O.D. but retains the original I.D. for your propshaft.

With this in mind, I checked my remaining stock and found that I have both type seals in stock and indeed...... 314167 has a larger O.D. but the same I.D. as the 300599/327031.
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

Are you saying that the 300599 seal's I.D. is too small for your propshaft
No.

Joe Reeves said:
OR that the I.D. is okay BUT the O.D. is too big/small?
Yes. The ID of 300599 is OK but the OD of 300599 is too big. 300599 has an OD of 0.875. My prop shaft housing only has a bore size of 0.750 .

Joe Reeves said:
This leads me to believe that perhaps seal 314167 may have a larger O.D. but retains the original I.D. for your propshaft.
I'm sure this is true but it takes me the wrong direction. My propshaft needs a lipseal with a 0.425 ID and 0.750 OD. 300599 has the correct ID but the OD of 300599 is too large.
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

300599-314167-3.jpg


Both of those seals have a prop shaft dia of 0.425, which is what I need. However, the one on the left has a 0.875 OD and the one on the right has a 0.9375 OD. Both of which are too large for my housing. My housing is only 0.750 .
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

I'm considering using a metric 10X19X7 seal...

Put the metric seal in today because it looks like I won't be able to find the seal I really need. It's a little tight on the propshaft itself but fits the bore of my propshaft housing OK. Ran the motor in a barrel for about 30 minutes or so this evening. Letting it sit for a while now to see if there are any leaks. Fingers crossed...
 

Joe Reeves

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

Okay, now I fully understand. Should I come across that item or info pertaining to it, I'll get back to you. Got to be a answer there somewhere if that original P/S housing and seal is indeed original.
 

samo_ott

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

Put the metric seal in today because it looks like I won't be able to find the seal I really need. It's a little tight on the propshaft itself but fits the bore of my propshaft housing OK. Ran the motor in a barrel for about 30 minutes or so this evening. Letting it sit for a while now to see if there are any leaks. Fingers crossed...

And... did it work?
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

And... did it work?


Well, I haven't pressure tested it because I don't have a fitting for doing so. However, I don't see any oil coming from the shaft seal or anywhere else. I'll take it out on the boat and run it for a day (probably Saturday) and then bring it home and drain the oil and look for water.

For now it looks like this is going to work.
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

I notice that the 2006 Sierra Marine catalog lists the correct mainshaft seal for this motor (18-2035) but they have a '-' for the propshaft seal. Wierd.

I did more research based on the prop housing numbers and it looks like there have been THREE different seals for this motor housing.

0.425 X 0.750 X 0.313
0.425 X 0.875 X 0.313
0.425 X 0.938 X 0.313

The latter two seals are readily available but the first one appears to be no longer made, by anyone--even National. Looks like the metric seal is the only option for my housing.
 

Agriculture

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Re: Evinrude 3hp Lightwin 3012-03700 prop seal

And... did it work?

Looks like the metric seal is going to work OK.

Does anyone have a "fuel tank mounting plate" for this motor kicking around? Mine is cracked/broken. I believe it's p/n 0203196 .
 
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