89' 100HP Mercury slips?

[mplummerjr]

I am not sure where to start and am a decent mechanic so would appreciate some help. My old SeaRay has been running great over the past few months. Now, the last two or three times out, right about at 14 mph when it almost hits plane and picks up to the next gear, it sounds like a huge slip and drops down to 9 mph or so and keeps doing this. Now, in playing around found that the more gas I give it more likely it is to happen while in the higher rpm's 4,000+. If it is running really low, about 3,500 or so can get right into the gear without issue. Where do I start? What is the common cause? Thanks in advance for your help.

 

[Barnacle_Bill]

Re: 89' 100HP Mercury slips?

Outboards do not shift gears. If you are saying the motor revs up but you go slower then you most likely have spun the hub in the prop. A prop shop can fix that for you.