Boat motor troubles 25HP Johnson

afrojojo

Cadet
Joined
Feb 28, 2012
Messages
13
I am running a 25hp Johnson, with an aluminum 10.5 x 11 prop, pushing a 1648 Crestliner Modified V.

The boat and motor performed well when I first got it. But last summer, I built a casting deck and added a trolling motor with battery. With the added weight, the motor does not perform as well as it did. I have adjusted the angle back 2 holes and experimented with the other holes. I found the current location of 2 holes back from the original was the best.

When I turn the throttle all the way and pick up speed everything sounds ok. When I get on plane and reach maximum speed, the motor starts chugging/whining. If I let of the throttle just a little it stops until I turn it all the way again. I am wondering if this is a prop issue? It seems to not do it as bad or at all when I have more people in the boat with me. Any ideas?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Boat motor troubles

Re: Boat motor troubles

Good Morning ,welcome,You did a pretty good job describing your issue but we need a lot more
details about your setup.Please read "read this first" at the top of the page.
I believe there is a maximum timing adance on your motor It limits how far the stator assembly can rotate.
adjustment is covered in the manual.There is also a link and sync that sets the point that the carb throttle
roller is picked up by the throttle cam on the bottom of the stator.
Now that this has been established as a motror problem a moderator may move it to the E/J section.
There still may be an issue with the prop do to the added weight.
If you have any questions questions about "read this first info please ask.
 

sutor623

Rear Admiral
Joined
May 23, 2011
Messages
4,087
Re: Boat motor troubles

Re: Boat motor troubles

Are you cavitating? Just wondering.
 
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