2008 175 optimax

rooster 33 · Post by **rooster 33** » Wed Mar 13, 2019 7:16 pm

Someone rear ended me at thanksgiving. And finally got my boat finished last week. Yes it’s been along time. It’s been a nightmare of a ride. My question is this insurance replaced all new lower unit and trim. My 1st test run I noticed the water was at 7 psi at 40 mph it used to be 12 psi. Then a alarm went off it was the port side over heating. Mechanic dropped lower today and said the water impeller was good. The merc tester said the port side was at 149 and the stbr was at 136. Water pressure said 0.5 what are the normal ranges. Thx.

MichaelB · Post by **MichaelB** » Thu Mar 14, 2019 4:56 am

Rooster:
Get registered at the Mercury forum at Bass Boat Central.
Read the sticky on details to include with your post, post your question and you will get some help.
They can help you with your Fury 4 also .... you are way overpitched with a 26p on a 175.
Good Luck.

http://www.bbcboards.net/forumdisplay.php?f=7

ash · Post by **ash** » Thu Mar 14, 2019 9:20 am

I agree that BBC is the place to go for setup and motor questions. I always thought that 10-12 PSI was the lowest you wanted a WOT. Something isn't right and i would think your mechanic would be dialed into these things and be able to tell you you need to lower your motor height for more water pickup or its the impeller / blockage.

JoeLanghans · Post by **JoeLanghans** » Thu Mar 14, 2019 5:39 pm

Check your engine height with the new lower and goods. Is it up too high? Then, check to see where your transducer is in comparison to the water intake, it may be throwing dirty water (air) into your water intake due to the ending height.

WRB · Post by **WRB** » Thu Mar 14, 2019 5:59 pm

If the impeller was new with the new lower unit and hasn't taken a set from being over heated it should be OK. 10 psi is minimum at any speed. The engine height could be too high and getting air in the upper intake ports, should be 3 1/2" from planning pad to level prop centerline to start with. The prop shouldn't affect heating but does seem at least 1" more pitch the a 175 can spin 5800 rom.
Sorry to hear about your accident.
Tom

rooster 33 · Post by **rooster 33** » Fri Mar 15, 2019 6:41 am

Thx for the info. I never thought about the new engine being to high. It was put back in the original location with a factory lower unit. I did check and the lower unit fins are sitting even with the bottom of the boat. I already found me a new mechanic. Thx again for the ideas.

WRB · Post by **WRB** » Fri Mar 15, 2019 3:41 pm

Fins? Do you mean cavitation plate? The prop shaft centerline is about 7" below the bottom surface of the cavitation plate. The plane pad is the flat surface in the center of the boats rear bottom area. If the cavitation plate is even with the plane pad surface the engine is 3 1/2" too low!
You need to find a new boat mechanic for sure!
Good luck,
Tom