Mercury 150 Black Max

[jgaryc3]

Hello again! Just to let everyone who doesnt remember me know I have a 1978 Mercury Black Max.

I have my steering issues figured out and the boat runs good now.

I have another issue:

When we start it up and try to get it going, the bow just rises and doesnt plane out.
If we pump the primer bulb hard, and then try to hit it again, it planes out good.

Now I have read on here and it seems like the fuel pump, no? Should I check the carbs? What is yalls opinion?

 

[Laddies]

Re: Mercury 150 Black Max

You need to start with the rebuilding of the fuel pump and checking any filters in the system

 

[jgaryc3]

Re: Mercury 150 Black Max

ok, I will do that. Also, when we are getting her cranked up (she takes a min after not being ran for a while) gas leaks out of the front of the motor. I guess it is coming from the carbs? Would this have anything to do with the fuel pump or is it another issue altogether?

Is it normal that it takes a mintue (more like 15) to get it cranked? I have had some people say yes on the older Merc 150 and some people say it should fire right up everytime.

 

[j_martin]

Re: Mercury 150 Black Max

Assuming you're talking 'bout a v6

Gas coming out the front is dirty needle valves, or a sunk float in at least one carb. The early V6's had foam floats, which sink in short order with the gasahol they foist on us as fuel these days. Good luck finding plastic floats. You probably have to score some carbs off'n eBay to get the floats.

Mine is cold blooded in cold weather, but if I compensate and prime it up good, including counting to ten on the choke, and squeezing the primer one more time before attempted start up, it pops right off. I humor it for about 20seconds with the choke button, and she's good to go.

A weak fuel pump will make it hard to start. Also, these things need good fuel delivery. If you're going hard, and it leans out, it can burn down in seconds. It needs good clear, not leaking suction line parts, a good diameter and condition primer bulb and hose, (Merc, not aftermarket) Clean fuel filter, Connectors either in good condition and OEM, (the plastic aftermarket ones just don't deliver enough fuel) or bypassed. On an engine that old, if the fuel lines have never been replaced, they are all suspect.

Been there, done that. Bought a lemon XR4 that is now a rocket.

Hope it helps
John

 

[Laddies]

Re: Mercury 150 Black Max

While your at the pump the carbs need cleaning too.

 

[jgaryc3]

Re: Mercury 150 Black Max

ok. am going to do the fuel pump. i looked and there are no in-line filters or anything and the primerbulb and line are new (mercury). The line isnt kinked and it appears that it would be getting good flow.

Like I said if we are fishing and then are going to take off, the bow just rises up and stays like that. if we go back to idle, pump the bulb hard, and then go to take off again, it rises fast, planes out fast, and rides out. hopefully doing the fuel pump will fix the issue.

I am still worried about those carbs though. How hard of a job is that?
The guy I bought it from was getting cancer treatment and did say it sat unused pretty much the whole time he was going through that. (6-9mos)

Any suggestions?