1978 Johnson 9.9 replaced impeller, grommet, and thermostat. Still no water :/

Purchased a 1978 Johnson 9.9 at an auction earlier this spring. The saga began with no spark so I used a multimeter to diagnose the powerpack. Replaced powerpack and started right up. But no water out the telltale.

Purchase impeller kit and replaced. Still no water. Removed power head to get at the common grommet issue and even though the grommet didn’t look half bad (appears to be fresh water only) replaced it. While the powerhead was off I blew air through everything and a large bug blew out of the block so I thought great that’s what the problem was it’ll for sure pee out the telltale now. Put it all back together, still no water. Removed thermostat and though it appeared to still function it was a bit crusty so I replaced. Removed lower unit and verified impeller housing slides onto copper water tube. Blew air from telltale tube and feel air coming out the lower unit where water would flow in. Thought I had it for sure.

still no water out the tell tale. I can feel a small amount of air and also some exhaust push through at idle.

My 4 year old daughter who I’ve been working on this project with says, “daddy I give up we’ll never get to go fishing” I really want to show her if you stick at something you can always get it figured out, but at my wits end on what to try next. Any suggestions?

Put more water in your test bucket.----Water must be 8" above the impeller!

racerone said:

Put more water in your test bucket.----Water must be 8" above the impeller!

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LOL, well that was easy. I owe you a or several!

I had tried both rabbit ears and a bucket and neither had worked. Apparently the rabbit ears didn’t seal well enough… Now I wonder if I really needed to do even half of what I had tried, but oh well I’ll just be happy I can take my daughter fishing. Her first question when I showed her it was working was, “when can we go on the boat daddy”

thanks again!

It certainly wasn't a complete waste of time. With all motors it is always good to get the bugs out. lol

What is the common grommet issue? Having cooling issues on a 1971 Johnson 125.

Jkrens said:

What is the common grommet issue? Having cooling issues on a 1971 Johnson 125.

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This was a problem inherent to the 9.9/15HP engines. The grommet sealed the water inlet tube to the bottom of the engine block. Over time the rubber would swell/warp and cause the grommet to close off the orifice and restrict water flow to the engine. The only fix is to remove the powerhead, replace the grommet and base gasket, and reinstall.