888 stumbles on hard acceleration

[harleyman1975]

Hi, I have been lurking here for a couple of years but never posted. Here is my issue. 1972 Cruisers Bonanza 22.5 with 302 Ford 188 hp I/O (888 mercruiser). Will accelerate if brought up to speed gradualy but if pushed forward quickly like if trying to pull a skier up it falls on its face and dies (leans out). This is the Holley 2bbl carb. One guy tells me to richen the idle mixture another says to have it Idle at 1100 in neutral (No way) I am thinking accelerator pump myself but it squirts when you push the little arm. Carb was rebuilt this spring when I bought the boat. This and the lower shifting cable are the only issues I have found with it since putting it in the lake 5 weeks ago. Any suggestions?

 

[ampedzach]

Re: 888 stumbles on hard acceleration

Give it a nice revamp. Get a Tune-up kit for it, some spark plugs, and maybe some wires. You can get all that for pretty cheap. Might help...

 

[cr2k]

Re: 888 stumbles on hard acceleration

Check the plastic cam on the throttle shaft that makes the pump squirt. It may be worn.
Also you can adjust the slack out of the pump arm.

 

[mrdjflores]

Re: 888 stumbles on hard acceleration

vacuum advance on the distributor??

 

[haulnazz15]

Re: 888 stumbles on hard acceleration

There isn't supposed to be any vacuum advance on a boat. All marine distributors are mechanical advance. I would be checking the base timing and timing advance first. Then looking at fuel delivery. Absolutely do not have it idle @1100 or you will shred the clutch/gears when going into gear. 600-700 should be pretty close to the range for idle. Enriching the idle screws also does next to nothing for acceleration issues. The accelerator pump and main jetting is going to be the areas of concern, as is fuel pressure.