BF50L milky gear oil, How many seals to replace?

I have a Honda BF50L 5 HP that has milky gear oil, can someone let me know what seal to replace? Thank you

Typically you go for the prop shaft seal first. It's the one that fails most often. Especially if you never pull the prop and inspect for fishing line wrap. Fishing line wraps are the #1 cause of prop seal failure and frequent inspection and removal of line and debris wrapped around the prop shaft is the best way to prevent seal and thrust washer damage. It's a "routine" most experienced boat owners learn to keep up on to prevent problems.

There is also a seal or seals for the main shaft as well as a seal for the shift shaft where they enter the gearcase. Those seals fail far less often.

Other things to keep in mind are the oring seals for the drain and fill plugs. Although they don't look like a big deal, leaks do occur there and it's a good practice to replace them every time you remove the screws.

The gearcase will build pressure as friction from the gears heats the oil. But, as the lube and air in the case cools down, a vaccum will occur at times and this will help water and air to intrude.

Things like water temperature changes and leaving the case submerged can help increase this intrusion.

Water and air being less viscous than the gear oil makes it possible for intrusion to occur while no oil leaks are apparent. So just because you don't see an oil leak doesn't necessarily mean that the case is fully sealed.

Most COMPETENT shops will pressure and vacuum check the gearcase when diagnosing leaks or after any repairs such as seal replacement.

Hope this helps and

Good luck.

Thank you very much