help with Big Twin lower unit problem

[march]

I finally got my 1963 40 hp Big Twin running after messing around with it all summer (it had been sitting for 5-6 years so had carb and ignition problems). The motor now runs great at low and high speed and I thought I was free and clear....until I realized I had a blown seal in the lower unit. I replaced the gear oil and after 5 minutes on the water, the oil was milky so I assume water is getting in. Also, while forward and neutral work fine on this electric shift, I have no reverse.

My local marina tells me lower unit seals are a common problem on outboards that have sat for years. He quoted me about $250 for labour and the seal kit. I'm wondering if I really need the "seal kit" or whether there's a way to know if one specific seal needs to be replaced. Does anyone know what seals are included in a "seal kit"?

Also, what's the likelihood that the reverse problem is linked to the seal problem? If unlikely, what would be causing that problem?

Thanks for any advice, I'm completely new to the whole boating thing and while it's unlikely I would try to repair this myself, I'd at least like to understand the problem(s) before I go back to the marina.

Marc.

 

[F_R]

Re: help with Big Twin lower unit problem

Big Twin or Lark?? It was the Lark that had Selectric shift. Anyway, never assume shifting problems are in the lower unit before you check it out electrically. The push button switch in the remote control gave a lot of trouble. Check the resistance readings and voltages at the terminals on the cable that comes up from the lower unit. A dealer or qualified technician knows what I am talking about. If he doesn't , get another mechanic.

You do need to keep the water out of the lower unit. No sense in going through the motions and not replacing the seals (seal kit).

 

[march]

Re: help with Big Twin lower unit problem

You're right, it's an Evinrude Lark - I thought that was a type of Big Twin.

Anyway, thanks for the advice. Any thoughts on whether a whole seal kit is required? Also, could I damage the lower unit by running the motor with water in the gearcase (I think the answer to this is obviously "yes" but want to make sure!).

thanks Marc.

Big Twin or Lark?? It was the Lark that had Selectric shift. Anyway, never assume shifting problems are in the lower unit before you check it out electrically. The push button switch in the remote control gave a lot of trouble. Check the resistance readings and voltages at the terminals on the cable that comes up from the lower unit. A dealer or qualified technician knows what I am talking about. If he doesn't , get another mechanic.

You do need to keep the water out of the lower unit. No sense in going through the motions and not replacing the seals (seal kit).

 

[F_R]

Re: help with Big Twin lower unit problem

Well, while any water in there obviously is not a good situation, a very small amount won't immediatly kill it or there would be trashed lower units all over the place. A large amount of water is death. My advice is to fix it. You could buy the individual seals, but the seal kit just makes it easier. You will need most if not all of them anyway. Well, OK maybe not the one between the upper and lower sections if you don't take that apart. But big deal...