3.0 hesitation at acceleration

[tjordan]

When I go from idle to acceleration I have severe hesitation and it wants to stall if I don't play with the throttle. I changed the accelerator pump but same problem. Could I have done the installation incorrectly? I've been told it could be bad fuel. What's the best way to remove the old fuel?
Mercuiser Alpha 3L with 60 hours. Fuel has sat for two months, no fuel water separator.

 

[dubs283]

Re: 3.0 hesitation at acceleration

there are fuel filters, one in the pump, one in the carb - check/replace them

have you checked fuel pump pressure??

when was the last FULL tune-up??

 

[Maclin]

Re: 3.0 hesitation at acceleration

Regarding the acelerator pump, pretty easy to check.. But first, you do mean the accelerator pump inside the carburetor, right?

If the accel pump is working well then you will see 2 very strong streams of fule spray out into the carb bores when the throttle is moved.

 

[tjordan]

Re: 3.0 hesitation at acceleration

there are fuel filters, one in the pump, one in the carb - check/replace them

have you checked fuel pump pressure??

when was the last FULL tune-up??

I saw posts about the filter being in the fuel pump 'canopy'. Am not sure how to open it up. I'll look for a diagram online. Is the carb filter inline in the tube where it enters the carb?

Last full tuneup was 2 years ago, 12 hours ago on engine.

 

[tjordan]

Re: 3.0 hesitation at acceleration

Regarding the acelerator pump, pretty easy to check.. But first, you do mean the accelerator pump inside the carburetor, right?

If the accel pump is working well then you will see 2 very strong streams of fule spray out into the carb bores when the throttle is moved.

Yes, the accel pump in the carb. I had this similar problem 3 years ago and replacing the accel pump solved it. Thought it would do the trick this time. Can I check for these streams with the flame arrestor off?

 

[dubs283]

Re: 3.0 hesitation at acceleration

I saw posts about the filter being in the fuel pump 'canopy'. Am not sure how to open it up. I'll look for a diagram online. Is the carb filter inline in the tube where it enters the carb?

fuel pump opens up by clipping the safety wire on the 3/8" hex bolt, loosen the bolt and the filter housing comes off

carb filter is in the housing where the metal line enters the carb, 1" wrench on the housing 5/8" flare wrench on the line connection

Can I check for these streams with the air filter cover and air filter off?

yes, and its not a filter per se, its a flame arrestor

 

[tjordan]

Re: 3.0 hesitation at acceleration

Awesome. I just opened the engine compartment and saw the wires around the nut and was pondering the wire around the bolt head. Thanks for pointing out it is the flame arrestor. I edited my post after I realized that. I'll let you know how it goes. Thanks

 

[tjordan]

Re: 3.0 hesitation at acceleration

Got the fuel pump filter out. I'll have to wait til tomorrow for the shop to open tomorrow to pick up a new one.
There was no filter that i could see at the carb end. Appreciate your time and knowledge.

 

[dubs283]

Re: 3.0 hesitation at acceleration

There was no filter that i could see at the carb end

did you remove the filter housing from the carb, 1" hex shaped housing??

 

[tjordan]

Re: 3.0 hesitation at acceleration

Ahh, it looked like it was part of the carb itself. I'll go undo it now. Thanks.

 

[tjordan]

Re: 3.0 hesitation at acceleration

Yep, dumb question. Kit has 3 gaskets, small one, large one, and one with both the small and large together. Mom sure is proud of her college graduate.

I hope this isn't a dumb question. I'm replacing the filters. On the fuel pump filter - how do you keep the smaller gasket on top of the filter while putting the canopy back on and securing it? The larger gasket fits up in there snug. I cleaned around where the smaller one came off but it doesn't seem to have a lip or anything to hold it up there. And if I just sit it on top of the filter it moves before I can get it up there.