You should find out what the "small cheap part on the distributor" is and how much it costs. Some of the distributor parts certainly aren't cheap.
If the motor is cheap and easy to fix why hasn't it been fixed?
Welcome, if you go to the Mercury EzPartsWeb (sysonline.com)
and put in your serial number you can find the part number for the filter.
For some reason it's listed under the Starter Motor category.
It's probably a 35-877761K01
I don't think that's a 1997. I'd guess late 70's to mid 80's?
It does have power trim/tilt.
It's the type with the pump mounted externally.
Can't say if it's worth it or not.
Power tilt might be worth the 300 depending on your market.
Just remembered that on the transducer cable near the connector at the dash there should be a label with a part number on it.
You could use that number to see what models use the same transducer.
The start position of the throttle lever should provide more rev's than the shift position.
Check the Throttle Friction Knob at the end of the throttle lever.
It may be too tight and stopping movement.
If that's not the problem you will have to look and see what is causing the issue.
I don't...
When in Neutral or Reverse the throttle grip movement is restricted in how far it can move.
When the throttle cable is adjusted properly the maximum rev's in Neutral are 5200 rpm and in Reverse 3200 rpm, depending on year.
A friend has a 16ft Lund SSV that weighs about 350 lbs with a 20hp honda.
2 of us in it is another 300, 2.5 gallons fuel and a 20 lb anchor so less than 400 total.
We get about 22 mph.
I may not have explained it well.
There won't be a mark on the cap.
In theory #1 can be any terminal on the cap.
The rotor doesn't have to point to the number one cylinder on the block, although it often does, just to the terminal on the distributor cap that has a plug wire going to the number...
For that era I think there's only a small number of keys that they used.
A lot of merc dealers will have a ring with a bunch of keys on it that you can use to match it up.
It will require you taking the boat or control to them or the ring of keys to the boat.
