it is just an idle mix problem all he needs is a screwdriver and a stretch of water to run the boat!
2004 BF90A4 JHTA Honda Outboard CARBURETOR Diagram and Parts
the idle jet is item 5 on that one.
What I can't tell is whether a CW turn is open or close. If it were me, I'd go CCW first, but that may be wrong.
As you don't sound like you are 100% certain, I'll puit this in basic steps. Apologies if I'm telling you old news.
- Do the "chok blip" test. Assuming it doesn't continue to stall and/ or throws you off the back of the seat when you do that test:
- take a digi pic or note of the screws' positions (so you can put them back in the same place if it doesn't work) and rememebr how far you have turned the screws so you can put it back.
- turn each of them 1/8 turn CCW. (1 per carb)
- test it.
--If it totally stalls or doesn't even start, turn the screws back to where you started, then turn them 1/8 turn CW & test again.
-- if it works, put the lid back on.
- if it seems to work a bit better, but still not brilliant (whichever way you end up turning the screws) , repeat with another 1/8 of a turn & continue to do so 'till it stops stalling.
- if you then want to be really anal about it, you can then turn the screws back 1/16 turn at a time 'till it stalls or hesitates and keep adjusting to & fro until you get an optimal setting.
Hopefully that is clear enough. The only thing I would say is I don't know these carbs, so if yours looks nothing like the pic, or you (understanably) don't want to trust my guess as to screw 5, hopefully someone will be along soon who knows that engine better than I do and can confirm / correct my guess.
The setting process still stands even if it is another screw!