performance related question --- 1996 Black Max 175

jeffunger

Cadet
Joined
Jul 3, 2006
Messages
8
Hi,

(short version) -- I recently (this week) upgraded to a 1996 175 HP Black Max from a 1984 150 Black Max. I put the propeller from the 150 on the 175. I rode it for the first time today and was generally disappointed. It would not go over about 4900 RPM and it did not "raise" the boat as much as the old 150. I noticed that this new motor did not trim as high as my old one. I will be talking with my mechanic tomorrow and at the moment I would like to believe the motor is operating fine and either it needs raised/lowered and/or I need a different prop. Before I talk with him I was hoping maybe to get some different thoughts.

I know enough to be dangerous; fishing a lot, but never really spending a great deal of time learning about performance considerations. I think motor height and the prop have something to do with this. The motor is on a 1983 18.5 foot Champion. With the old 150 I ran about a 5 foot rooster tail, 54-5500 RPM, and it lifted the front end nicely, I always felt the boat was riding somewhere right behind the seats.

Today it definitely ran "flatter" (the front end did not rise as much), it felt like the boat was riding a couple of feet in front of the seats, I didn't have any rooster tail (maybe a foot, if that --- the motor would trim any higher), and I couldn't get over 4900 RPM. One thing my mechanic said when I picked it up was that he thought my prop needed "cupped" and balanced.

Thanks in advance for any feedback and thoughts,

Jeff
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,446
Re: performance related question --- 1996 Black Max 175

You have either motor or set up issues. Good range for that motor is 57, 5800(way more if you were like me:D) Tha 2.5 175 should be like day and night compared to your little 2.0 150. Find someone in your area that has some knowledge on "how to" and what to" do on your set up.
Maybe someone here can get ya headed in tha right direction.............

GL..........D

JAN. You might go to BBC. They have a Champion forum.........
 

jeffunger

Cadet
Joined
Jul 3, 2006
Messages
8
Re: performance related question --- 1996 Black Max 175

thank you ---- I was kind of thinking that way -- motor seemed to work fine, it just doesn't seem to want to "lift" the boat enough/right
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: performance related question --- 1996 Black Max 175

Sounds like setup to me. Engine height or setback.

Does the trim system run normally at full engine power? Does it go to the end of the high pressure rams under power as indicated on the dashboard indicator?

Is the engine mounted at the same height as the old one? Is it the same length engine?

The prop should run the same on this engine as the old one, unless the LU gear ratios are different. Stock they should both be 1.87:1

On another note. When I bought my XR4 it was pretty doggy. There were about a dozen fuel, timing, and setup errors on it, and it's now a champ.

hope it helps
John
 
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