3 hp Evinrude - RTV Sealant (lower unit)?

[rob reber]

I have worked on a few small outboards over the years, and I have always used RTV sealant of some sort on the lower unit. I even will put it in the screw holes. I have been reading a few posts on this site and others, and the general consensus is that you should not put the RTV sealant in the screw holes. It looks like I have been "screwing up" all these times :^) Is there a better type of RTV sealant to use, blue, clear, etc? Thanks for all your help. I have been learning a lot from this forum - thanks!

 

[HybridMX6]

Re: 3 hp Evinrude - RTV Sealant (lower unit)?

I believe BRP/OMC makes a gasket sealer they most manuals will recommend using (factory manuals that is, not Seloc). It says to use it in the screw holes to make a breakable seal so they can be removed in the future, yet the stuff will help seal out water from getting in the threads. I don't know how well this truthfully works, but I do it. I had some from rebuilding a powerhead last year. Can be purchased from your local dealer, same as the grease. They also recommend "moly-lube" for some applications here and there.

 

[ENSIGN]

Re: 3 hp Evinrude - RTV Sealant (lower unit)?

Well i guess i'm just old school but permatex #2 for a gasket sealer has been working for the past 40 years and you can't beat neverseeze on bolts&nuts

 

[emckelvy]

Re: 3 hp Evinrude - RTV Sealant (lower unit)?

I use Permatex #3 Aviation-Type non-hardening gasket dressing on the gearcase halves and on the fastening screws. Seals well, keeps salt out of the screws and comes apart nicely when needed. The silicone tends to be a bit messy and really hard to keep the excess from squeezing into the gearcase, then curing/flaking-off, then having bits of RTV circulate inside the gear housing.

Other than that issue and the mess when you disassemble the next time, silicone will sure seal it up but I prefer #3.

HTH..........ed

 

[rob reber]

Re: 3 hp Evinrude - RTV Sealant (lower unit)?

Thanks much - ENSIGN and emckelvy! A question for emckelvy... Do you use the Permatex on the mating surface between the gearcase housing and the lower unit?