Merc 7.4l hard to start

So I just bought a chap 2330 and it has the 7.4 bravoIII when I water tested it it ran great and fired right up. Now when it is cold and I try to start it it takes Forever! It will kill a battery before it fires up and I noticed a can of "quick start" in one of the compartments (wish I had noticed before I bought the boat) So anyways once it is warm it runs great and fires up first try every time. The only thing I did notice is under WOT it will bog for about .05 of a sec..not even enough for most people in the boat to notice and that problem is intermittent because it didn't do it after driving the boat for about an hr. So I'm thinking fuel filter or fuel pump because I did put the quick start in (I had someone else do it as I was cranking it over) and it fired up and ran for a sec off of the quick start then died right away, which tells me it has spark.
I'm going to change the fuel filter because that should be done anyways! and after that I will possibly change the fuel pump but that is starting to get pricey if that is not the problem.
Any Ideas?
thanks
Nate

Re: Merc 7.4l hard to start

Might want to go ahead and post some serial numbers for the engine/drive and model year as that could make a difference in the type of troubleshooting.

Mark

Re: Merc 7.4l hard to start

mine will crank for a while too if I just try to crank it, but if I pump the gas twice it pops right off everytime. Its almost like the fuel has ran back down the line. Mine is a mechanical pump though.

Re: Merc 7.4l hard to start

Sorry the motor is a 1997 7.4l merc carbed I don't have the serial number right now but I can get it.

92rslt1 said:

Mine is a mechanical pump though.

Click to expand...

Mine is also a mechanical pump and it seems like it might be losing its prime as well.
What I'm going to try is get some one to pump my throttle while I watch the carb to see how long it takes to start squirting in fuel
thanks
Nate