Plugged speedo hole on a Merc 115 Pro XS?

[JohnP]

Been a issue since I got it.  Use my graph for speed so it's not that big of issue but would be nice for it work since its there ;).  Had been able to pick out in the past but this last time I've picked all i can and it's still not working.  Seen suggestions to try and blow it out from the other end but can't figure out which tube would be the Speedo tube if there is on externally that I could up to?.

[fishinwrench]

3/32 drill bit, cordless drill, slow speed.

[JohnP]

1 hour ago, fishinwrench said:

3/32 drill bit, cordless drill, slow speed.

How far in?  

[fishinwrench]

There will likely be water trapped in it, so when the water starts running out you've gone far enough.    You're not going to drill through the housing without knowing it...so no worry's.  Just be careful not to wallow around in there or you might break the drill bit off in the cavity.  All you are likely extracting is soft waterlogged wood/plant debris.  Although I have had some that were clogged with sand, so if it feels gritty and like you are drilling into rock or glass then reverse the drill and back out of there.  If it's sand then you have to try high pressure air from the other direction, and there's a 50/50 chance that it's clogged for good.