Lower Unit Problem.

[Knockerjoe]

I have twin 1996 200 Yamaha motors. Recently I had a some skeg welding done on my starboard side motor. The lower unit got very hot so I decided to pressure check my lower unit. I drained the oil and pumped in 14 psi. It immediately leaked down and i could here the air coming out of the prop seal area. <br />Curious, i then tried the same test to the port engine and got the same results. Both motors will holds steady at 11 psi but will blow past the seal any higher.<br />The manual states that it should hold 14 psi for 10 seconds?<br />Also can someone explain replacing the lower unit seals as the manual does not give specific instructions on doing so.<br />Thanks for the help!

 

[rodbolt]

Re: Lower Unit Problem.

my advice would be to let them be. I would rather do a vacum test on a yamaha. both seal lips face out on a yammi so I am amazed they hold much more than 6 PSI or so and the older ones hold 3.3 PSI. so far the replacement method is to remove the prop shaft bearing carrier then replace the seals. make sure you measure the depth of the seal before removing them.<br /> good luck and keep posting but that big heat sink(gear case) did not get warm enough to damage propshaft seals.<br /> I would be more concerned with the carrier oring but I have never seen skeg welding damage one.