Evinrude 4.5 clogged tell tale

[tgr23]

Just getting an unused motor running after 10 years. The tell tale is clogged with some hard deposits. I've scraped out about 1/2" worth but it's still clogged and my tools can't reach anymore. How aggressive can I get with this? Run a drill bit up there? I've heard that there might be a grommet under the powerhead that might need to be checked. Thoughts? ideas?

Has a new water pump. Tried blowing air from the bottom up, no luck due to clog.

Thanks

 

[Good Trout To You Sir]

I'm interested in the answer to your question since I'm working to rehab a 1998 4HP that possibly has a blockage inside the overboard indicator. Is it OK to use compressed air to force air into the tell-tale (opposite direction of water flow)?

 

[kbait]

I’ve done that to stubborn 9.9/15’s to clear blockage..