I got the chance to get out on the water with my new 20 inch, 4 hp, Mariner. At first glance it looked like the prop would set deep enough. If two people sit at the stern, there would be no problem. BUT if I go solo, which is typical, the prop cavitates as my weight moves forward in the boat. When I’m on the bow, I can’t see the prop but it sure sounds like it’s totally out of the water.
I posted on a Facebook group for ideas. I was totally surprised by the amount of responses. Many said take it back. Some said lower the mount on the transom. Some said change the mount where the motor clamps on. One said to add a new mount on top of the existing mount. Another also said that there may be a kit available from MarineParts.com to extend the lower end by 5 inches. I’m hoping that one is available for this model and it’s not too costly. If not, I will try to lower the mount at the transom by making an adapter plate using heavy aluminum angle.
In the mean time, I decided to investigate my old 25 inch Mariner. I started by checking the linkage by pulling out the rubber plug on the lower housing. I loosened the clamp to discover that I could put it into forward. This meant that the problem was in the shift linkage up to the motor. To see the top of the linkage, I had to pull the powerhead completely out of the housing. With the powerhead removed, I was able to work the shift lever easily. I soon noticed that the bolt that clamps the shift linkage to the lever had backed out and was hitting the bottom of the powerhead housing (notice the scratches). I carefully reassembled everything and gave it the barrel test. It works great.
It looks like I’ll be putting the old 25 inch back on the boat when I can. I just had my second hand surgery for “trigger finger”. The first was three years ago for my right thumb. Last week was on my left index finger. It’s a quick out patient procedure where the band that the inflamed tendon passes through is cut apart. It takes a couple weeks to heal and that finger will never lock again and the pain and swelling will be gone too.