C172 pilot reported engine power fluctuations during cruise required a diversion to a nearby airport. Pilot stated the checklist does not provide a procedure for this problem and the placement of the placard for switching fuel tanks is in a location that is difficult to view.

Narrative

I have flown 172s for the last 10 years. I recently purchased a 172G model. Placarded on the fuel selector is a note stating that pilots are to switch to a single tank from 'both' after leveling off above 5000 feet. Almost no Cessna pilots do it; myself included until today. The general feeling around the community is that it is not important and that it was a political stunt by Cessna years ago while transitioning to Lycoming engines. I knew about the issue when I purchased the aircraft but don't fly often at higher altitudes and so didn't have it top of mind. I had looked into it at the time and found that it wasn't important based on community comments and so I forgot all about it. I was flying from ZZZ1 back to ZZZ2. As I was flying past ZZZ I noticed a temporary drop in engine RPMs. After about 30 seconds I lost engine power completely but then it would surge to full power and back to zero. Engine power continued to come and go. I followed the checklist; advised ATC and landed at ZZZ without issue. The issue was that the standard loss of engine checklist doesn't follow the required remediation for the issue; so pilots are not able to regain power. The published remediation requires you to fly on one tank for one minute; and then switch to the other tank; but this is not standard practice. The other issue is that the placard is down by the fuel selector; which is not something you look at often; so the issue is out of mind and often forgotten. Contributing factors are: 1. The Cessna pilot community doesn't see the issue as real. 2. The emergency checklist doesn't deal with the issue. 3. The placard is on the fuel selector where nobody is looking in flight.Other comments are that I found myself very distracted in taxiing back to the ramp. Controllers should realize that a pilot is not in his/her normal state of mind after an incident like this and offer more support for taxi at an airfield they are probably not familiar with nor have taxi diagrams ready; etc. A progressive taxi should be standard practice after a situation like this. Its easy to ask for; but I felt the controller was not aware of the compromised mental state a pilot might be in after a flight like this.