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Added tell tale to 85HP V4..sputtering a bit on muffs...normal?

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BadDecisions

New member
Motor is a '73 Johnson 85HP V4. Added a tell tale via the cast in boss on the upper starboard side of the motor, and ran a 3/16" hose down through the lower cowling. I've been meaning to order up the factory lower cowling fitting, and keep forgetting. I just did the impeller replacement, using a full OEM kit with new plastic housing/stainless ring, and have only run the motor on muffs since.

Unfortunately, there was once, that after running the motor for about 15 minutes, I shut it down, turned off the water, and restarted it about 5 minutes later without remembering to turn the water back on..probably ran it for about 30 seconds before remembering the water was still off. The next day I added the tell tale to see if I damaged the impeller.

Problem now is that I'm not getting what I'd consider to be a strong stream, and it's a bit...sputtery, for lack of a better term, lol. I'm still running it on last season's gas, so I'm assuming that's why it's also running a bit rough. Is this normal for running on muffs? It got a bit stronger with additional RPM, but never to the point that I'd consider it a "strong" stream, and still was a bit interrupted at times.

This is the first outboard I've had, always ran I/Os before, so I'm not really sure what I should expect. Or is this a case where I really do need the proper lower cowling fitting as a restrictor? I have a machine shop in the garage, so I can always make a through fitting to choke it down some if needed.


 
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Put it in a barrel of water 6 inches above the cavitation plate you get a false posative when you charge the pump with pressure the true test is on the water it could be just sucking air from the muffs?
 
Lake is only 20 minutes away...I can drag it down there for an in water test, just figured if it was an obvious problem now, it saves me a trip. Only barrels I own are steel burn barrels, and they all have numerous holes in them courtesy of 00 buckshot, lol.
 
You cannot test a water pump by running on muffs. The pump is not pumping when you do that---only allowing hose water to pass through.
 
I figured it had to be doing something...water wasn't making it to the motor until after I started it up. Tried it a few times thinking maybe the impeller just had stopped in such a way to block water from coming in, and every time water didn't come out of the tell tale until after I started the motor, and even then it took about 20 seconds of running before it started flowing.

Either way, I'll see if I can find some time tomorrow morning before it gets brutally hot to get it in the water for testing.
 
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