Questions - lower unit, 1990 40HP Evenrude

[TerryMSU]

I just got done changing the oil on my new-to-me 1990 40HP Evenrude. Some of you may remember my earlier post where I could not get the upper fill-and-drain screw out even with my biggest screw driver. I purchased an impact screw driver. Even with the impact screw driver, I had to get my wife to brace the lower leg while I hit the impact screw drive and it took a good solid hit to break the screw loose. The lower screw was also a bit of a bear, but the screwdriver had not been cammed out of the slot and so I was able to break it loose. Niether screw had the extra o-ring or nylon washer on it. (Both had the o-ring that is part of the screw.) Are they supposed to have an extra o-ring (on the upper screw) or nylon washer (on the lower screw) in addition to the one that is part of the screw? Mine do now, but is it correct? My boat store sold them to me before I realized that the screws were questionable.

Thanks,
Terry

 

[kjdunne]

Re: Questions - lower unit, 1990 40HP Evenrude

If the screw plugs have a groove on the underside of the head for the o-ring to sit in, use o-rings. If they are flat, use nylon washers. Replace them EVERY time you remove the plugs. If the screwdriver slots are chewed up, buy new plugs. I hear the newest ones have an allen type head. Anyway, with new washers/o-rings just tighten well with a screwdriver, they'll seal. I've seen guys use a screwdriver bit on a ratchet handle, which is why you can't get them back out.