So this is more of an informational / sparking conversation posting, as I don't really think I have a question.
I have a Johnson 10-24509-01 raw water pump (or F4B-903: not sure which is the real part number) on my Yanmar 2GM20F engine from 2004. Around a month ago, I noticed a small puddle of seawater under the pump (maybe 3" diameter) after running for a few hours. First leak in 16 years. By last weekend, that had grown to more like 1/2 cup of water (a very large puddle) over a 3.5 hour run, and I could see maybe 1 drop every 1-2 seconds coming off the pump. Figured it was probably the seal around the shaft.
So I followed the instructions kindly posted by Ken13559 in 3GM30F Raw Water Pump , and took it all apart. When I got the lip seal out, I thought the problem was pretty obvious. Check it out (after and before removal, and different sides):

It looks like the spring (that I assume is in there around the inner rubber ring) has rusted so badly that it has pushed right through the rubber on the back side (non-impeller side) of the seal. Anyway, it seems to be a GACO part with a part number which says DPSM 12247. Ken13559 , in his writeup, had it as "Oil Seal p/n: 12x24x7-TC-NOK", which I couldn't find anywhere online. I ended up calling Depco (Depco Pump Company). They didn't want the seal part number: just the F4B pump number. The guy said "you probably couldn't find it because we have all of them here...". Haha. Anyway, I ordered just the seal from Depco for around $10 (including shipping, I hope), vs. some $55 for a kit off of eBay which contained lots of parts I don't need. (The bearings look and feel fine.)
I have a Johnson 10-24509-01 raw water pump (or F4B-903: not sure which is the real part number) on my Yanmar 2GM20F engine from 2004. Around a month ago, I noticed a small puddle of seawater under the pump (maybe 3" diameter) after running for a few hours. First leak in 16 years. By last weekend, that had grown to more like 1/2 cup of water (a very large puddle) over a 3.5 hour run, and I could see maybe 1 drop every 1-2 seconds coming off the pump. Figured it was probably the seal around the shaft.
So I followed the instructions kindly posted by Ken13559 in 3GM30F Raw Water Pump , and took it all apart. When I got the lip seal out, I thought the problem was pretty obvious. Check it out (after and before removal, and different sides):


It looks like the spring (that I assume is in there around the inner rubber ring) has rusted so badly that it has pushed right through the rubber on the back side (non-impeller side) of the seal. Anyway, it seems to be a GACO part with a part number which says DPSM 12247. Ken13559 , in his writeup, had it as "Oil Seal p/n: 12x24x7-TC-NOK", which I couldn't find anywhere online. I ended up calling Depco (Depco Pump Company). They didn't want the seal part number: just the F4B pump number. The guy said "you probably couldn't find it because we have all of them here...". Haha. Anyway, I ordered just the seal from Depco for around $10 (including shipping, I hope), vs. some $55 for a kit off of eBay which contained lots of parts I don't need. (The bearings look and feel fine.)