Well, the Fastwin is "running"

[mr-asa]

1956 Evinrude Fastwin 15HP, 15016 serial
Running in a 25-ish gallon bucket on a stand

Really, she’s more spitting and coughing. I can only get her to stay running at mid-throttle, if I lower the RPMs she starts to buck and spit (very glad for those rubber bumpers,) if I try to raise the RPMs she falls flat and dies off.

While this is happening, I looked back behind her and saw that there was no water spitting from the weep hole. After I shut her off I put my hand on the powerhead and it was hot enough to make me worry that there wasn’t any airflow. I checked the impeller and it was new enough that it tried to regain it’s shape after I pulled it out of the lower unit, so I didn’t bother replacing it.

Maybe had her running for a minute or two total between a couple starts.

Any clues what could A) be causing it to run so rough B) run so hot?

[chris-p]

Any new motor to me I change the impeller. Perhaps the vanes are worn. Air hole open on the housing? Seal down the plate? Housing worn? Grommets in good condition? Grease grommets before installing gearcase? Did you blow out the water circuit to ensure she is free and clear? Is the pump actually submerged? The water line is a few inches below exhaust outlet. That pump is not self priming, you cannot just cover the water inlet. Just a few thoughts.

What are the needles set at? Have you gone through the carb? Go through linc n sync?

[mr-asa]

In general I change the impellers immediately as well, but the vanes looked 90% as good as a new pump, couldn’t really see any wear on them. Plate and pump housing looked ok, some wear but I have other motors that run fine looking like this one does. Hole is open, grommets were flexible and looked good. Didn’t blow open the passages. It is completely submerged.

Carb was just taken apart, gone through and cleaned. I mentioned in another thread that I noticed some damage to the low speed idle needle, but I cleaned it up and I am not convinced that is the culprit as it was acting like this before I tore the carb down and checked it. Haven’t checked sync yet.

[weedlessdrive]

Sounds like you need to check the water circuit. Maybe drop the lower unit and hook a air hose up and see if it has flow. Could be dirt dobber clogged line or exhaust water ports.

[chris-p]

yeah, drop the gearcase and either use air or the garden hose to flush the system. Put some grease or oil on the grommets and water line before installing, prevents pinching which restricts flow.

You could drop the whole gearcase in water, and spin the drive shaft to ensure that the actual case pumps water. That will narrow down to whether your issue is in the gearcase, or the powerhead side.

[mr-asa]

I got her pumping water nicely, but she still runs spottily.

I think there might be an air leak somewhere? I have new gaskets through the intake system and have rebuilt the carb
When I start her, I pull the choke and start cranking on her and within a couple pulls she starts. However she only runs with the choke pulled out. Any attempt to run without the choke kills her as well as if I twisted the throttle to the stop position.

[chris-p]

That motor is famous for weak crank seals, both top and bottom. Likely sucking air, making it over lean. Choking it helps even it out.

always a good idea to change those seals anyways.

thats my guess

[Mumbles]

Here’s the famous seal Chris is referring to. These are ‘as found’.

[mr-asa]

I will pull the powerhead and check.
I assume these seals are still readily available?

Anything I should know when I replace them? I don’t know if I have a manual for the Fastwin in particular

[jeff-register]

Get the part numbers somewhere before calling a parts house. Maybe someone will post that for you.

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