First of all, I am completely new to the boating game.
I purchased a little 82 15 foot sea swirl. What you would call a runabout I guess, its a closed bow, with a 78 55hp Johnson 2 stroke. I heard it run before I bought it, but it didn’t have a prop. I tried to research props but couldn’t really find what pitch to use. So I guessed and put on a 15 pitch. On the water the boat got up to maybe about 15mph with the bow up in the air. Also very low rpm,s. So I did some more searching and finally found the Solas website. I ran it through their prop finder and it came up with a 9, 10, or 11. I installed an 11 pitch. I also added a tachometer. On the water it took off pretty good, the boat got up and flattened out and I could see over the bow. The tach got up to almost 3000. WOT is 5000 on that motor. I don’t know my speed, but I was mov,n along pretty good.
What happened next is what bothers me most. I shut down on the lake for about an hour. I tried to start it up. I chocked it which I guess I shouldn’t have because I obviously flooded it. I opened up the throttle a little and cranked it till it started. It took a couple minutes to burn off the extra fuel. When I started to go, it started off good at first but then kinda got stuck around 1900 rpm,s. It gradually gained speed over more than 5 minutes to finely get up to the 3000 rpm. I shut it down again for a few minutes. I started it up without the chock and it still seemed to be rich. When I started out, it did the same thing again. It took a few minutes to get up to speed.
So I’m wondering, could running rich cause a problem like that? The weird thing is that the first time I started out it got up to speed pretty quickly.
Or does it just need a lower pitch prop? 9 seems to be the lowest pitch.
Not sure what step to take at this point. Maybe someone who knows these motors can give me a place to start. .
Oh, and the compression is 100 on #1 and 110 on #2. The lakes I go to are at least 6000 ft. elevation.
Thanks for the help
I purchased a little 82 15 foot sea swirl. What you would call a runabout I guess, its a closed bow, with a 78 55hp Johnson 2 stroke. I heard it run before I bought it, but it didn’t have a prop. I tried to research props but couldn’t really find what pitch to use. So I guessed and put on a 15 pitch. On the water the boat got up to maybe about 15mph with the bow up in the air. Also very low rpm,s. So I did some more searching and finally found the Solas website. I ran it through their prop finder and it came up with a 9, 10, or 11. I installed an 11 pitch. I also added a tachometer. On the water it took off pretty good, the boat got up and flattened out and I could see over the bow. The tach got up to almost 3000. WOT is 5000 on that motor. I don’t know my speed, but I was mov,n along pretty good.
What happened next is what bothers me most. I shut down on the lake for about an hour. I tried to start it up. I chocked it which I guess I shouldn’t have because I obviously flooded it. I opened up the throttle a little and cranked it till it started. It took a couple minutes to burn off the extra fuel. When I started to go, it started off good at first but then kinda got stuck around 1900 rpm,s. It gradually gained speed over more than 5 minutes to finely get up to the 3000 rpm. I shut it down again for a few minutes. I started it up without the chock and it still seemed to be rich. When I started out, it did the same thing again. It took a few minutes to get up to speed.
So I’m wondering, could running rich cause a problem like that? The weird thing is that the first time I started out it got up to speed pretty quickly.
Or does it just need a lower pitch prop? 9 seems to be the lowest pitch.
Not sure what step to take at this point. Maybe someone who knows these motors can give me a place to start. .
Oh, and the compression is 100 on #1 and 110 on #2. The lakes I go to are at least 6000 ft. elevation.
Thanks for the help
Last edited: