dry exhaust

[Michael Pietro]

I have a Yanmar 3Gm 30F which runs beautifully, about 1500 hours. After a few months of non use I started it and noted no raw water in the exhaust. I immediately turned it off. Scrubbed the seacock opening, cleaned the strainer, replaced the impeller (which was intact). Bottom line, if I disconnect the raw water line from the exhaust elbow and run the engine, it gushes. If I connect it there is still no water in the exhaust, although I run the engine for less than a minute like this. I can only think:

1) there is some type of obstruction in the exhaust, or
2) the silencer has a large water capacity and I just need to run the engine longer.

Thoughts?

[DougR]

The water injection elbow has corroded/rusted shut and it won’t pass any water.
Check it out before you melt the hose or water lift muffler.