Slow to get on plane Black Max 150 fixed!

lmoreau

Seaman
Joined
Mar 11, 2004
Messages
59
I had one of the 89 Black Max's that would stumble and not go to full power from a dead stop until the boat was in motion for some time, then it ran fine...<br /><br />Well, I took the fuel pump apart and the top gasket was broken. All of the diaphrams were very 'stretched out'. The top one may have had a pinhole leak in it. I changed them out, put in the new check valves, and took the boat out for a test yesterday. Boat now leaps out on plane, and I can hit 5900 RPM instead of 5600, giving me a mile an hour or two...briefly broke 60, to 60.3. Before, it was right at 59. Anywho, that's not important...what is is that it just accelerates smoothly now. It seems to maybe idle better as well. Still doesn't start like an EFI, though!
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Slow to get on plane Black Max 150 fixed!

Even the Merc EFIs don't start like an EFI. ;)
 

down_time_1

Seaman Apprentice
Joined
Jun 30, 2002
Messages
42
Re: Slow to get on plane Black Max 150 fixed!

I had a 135 carbed merc and have a 2004 150efi turnkey, their is a big diffrence. esp when cold and at idle. :p
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Slow to get on plane Black Max 150 fixed!

bad fuel pumps rarely happen on well maintained rigs. on the mercs,yammies and others that use a block mounted diaphram pump always replace or rebuild every 3 years and it never fails.<br /> but that also applies to water pumps, t-stats and pressure control devices. I make most my money on reactive maint instead of pro active :) :) . but after many years Ihave found the price of fuelpumps and water pumps stay the same no matter how many pistons ya buy with them. :)
 
Top