sonar not working at high speed

[hardwater fisherman]

i have a hummingbird paranhamax 160 it worked well at top speed with my 28 hp. i installed a 40 hp and i get a big rooster tail coming off the transducer and it reads 500 ft deep. i have no manual for this sonar so does anyone know what to do? i thought maybe raise the transducer does that seem correct?

 

[Capt'n Chris]

Re: sonar not working at high speed

i have a hummingbird paranhamax 160 it worked well at top speed with my 28 hp. i installed a 40 hp and i get a big rooster tail coming off the transducer and it reads 500 ft deep. i have no manual for this sonar so does anyone know what to do? i thought maybe raise the transducer does that seem correct?

http://store.humminbird.com/media/document/PiranhaMAX_150-160-170-180-190c.pdf

 

[hardwater fisherman]

Re: sonar not working at high speed

thanks

 

[mikphilips]

Re: sonar not working at high speed

Moving the transducer up or down may solve the problem. Your transducer wants to ride in clear water (no bubbles or turbulence) for the best look at the bottom. If both engines produced a similar planing angle while running, then it may be the additional weight (guessing since 28 to 40HP engine) is causing the transom to sit lower in the water.
This may mean that raising the transducer would help, but you might study the current setup while running at plane to find the clearest water for the transducer. The bottom face of the transducer usually wants to be about 1/4" below the bottom edge of the transom, min 24" away from prop.