1/8 inch hole in back of lower unit on Yamaha 115

lexkyboater · #1 April 9th, 2007, 06:42 PM

It's a 93 model, if that matters, but the guy I bought it from says that the 1/8 inch hole just above the gearcase in the lower unit is for the speedometer gauge. I checked lower unit oil after we ran it 10 minutes in a lake and it's clear w/o any water in it. The hole in the lower unit is clogged up so he says speedometer doesn't work. It doesn't have one of the old-style water pick up tubes installed on the boat. If this is a water pick up inlet, and it's clogged, can I stick something in the hole to unclog it? I ordered the Seloc manual for this motor today too. The motor is on an 83 Cheetah. Thanks for any info, Steve

WillyBWright · #2 April 9th, 2007, 08:09 PM

A paperclip might work. Back-blowing with compressed air in the speedometer hose might work. If it's bad enough, a tiny drillbit is a last resort. Just be careful not to drill metal. It goes in about 1/2".

JUSTINTIME · #3 April 9th, 2007, 08:58 PM

compressed air is the best
even the caned air works

lexkyboater · #4 June 22nd, 2007, 03:37 AM

Finally got around to checking on this. 110 psi on my air compressor didn't do it, even after several attempts, so I ended up working a small drill bit and a bent fishing hook with the point dulled in there, and it ended up being about 1 full inch deep. I could tell when I reached the end because I felt/heard a metal sound. After about an hour working with it, finally got it to blow out.