Looky what I found RD/RDE-17 paint burning.

[frankr]

#233860

There have been questions lately about paint burning on RD / Big Twins and a service bulletin. Guess what? I found the bulletin just now. Read & enjoy.

[Mumbles]

#233870

Thanks for posting that bulletin Frank. It was explained to me a few years ago but I’d forgotten it.

Here’s what it looks like in real life. The screw mentioned has been temporarily removed in this photo but the letters ‘AE’ can clearly be seen stamped into the top of the block. This motor is a ’55 Evinrude Big Twin. The Johnson RD should be the same.

Just looking at this photo and the drain hole looks a lot bigger than 5/32″. Since this powerhead hasn’t been installed yet, I better check it.

• This reply was modified 3 years, 1 month ago by Mumbles.
• This reply was modified 3 years, 1 month ago by Mumbles.
• This reply was modified 3 years, 1 month ago by Mumbles.

[Buccaneer]

#233882

I just looked at old photos of my RDE-17, and I believe it has the extra hole drilled.
No idea if it has the AE stamped on it.

Prepare to be boarded!

[fleetwin]

#233897

Cool! That hole in Mumbles’ block does seem a little big, kind of surprise they wanted it that close to the exhaust ports…I guess they wanted the water aimed near where the hot exhaust was spraying out…
Will definitely save this post, thanks Frank and Mumbles!

[olcah]

#233908

Interesting to see design change between these 1955 RD17s and the 1956 RD18s. Here are a couple of RD18 photos. One shows a new boss apparently with a small nozzle in the location of the drilled hole. The other shows just the cast boss with no drilling but there looks to be a new hole cast in below? Neither one shows the original drain plugged. Seems the design was still evolving.

[Mumbles]

#233919

And here’s what I think is a ’58 Big Twin. No screw, no drain boss. Back to basics?

[olcah]

#233923

Gotta love it. 😊