I have had my 2018 Honda BF250 /Phoenix 721 for 3 seasons now and have been playing with several prop combinations and set up's for all 3 years. I was told by just about every person that I talked to including Honda dealers, Honda staff not to mention a few custom prop shops to always run with all pvs holes plugged on a Honda outboard. They told me because the Honda is a four stroke the prop should never be vented"PLUG ALL HOLES" for best hole shot.
The first 2 of 3 years I have owned this set up that was fine and I only had a very minor difference in top end and hole shot from spring thru fall. However this year in New York state were I live, and run my boat most of the time we have had several weeks of temps over 90deg with lots of humidity the Honda was not even getting on plane with a full load. However the option of going down in pitch was out because my WOT rpm's are fine it was ONLY a hole shot issue.
I made a call to a few prop guys and 1 of them said it was ok to vent a pop run on a Honda " a little bit", I also put a post on the "prop section" of this site and fund several people vent their props for 4 stroke outboards. Yesterday I opened up 2 of the 3 holes on a Tempest and it made a night and day difference with the boat jumping up on plane. I do have to admit it did produce a few too many rpm's so I plan on closing 1 more hole and I think it will be just perfect.
My question is do any of you guys run with some form of minor venting, like 1 out of 3 holes open or just small vent plugs in all 3???