still bogging down

[jrl]

replaced fuel filters, added fuel stabilizer, cleaned carb, and when still when I accelerate quickly as if I was pulling a skier the engine bogs down and will quit if I dont come off it any ideas? any info would be greatly appriciated. It is a 86 mercruiser 140, in a 19.5 ft Webbcraft

 

[fireship1]

Re: still bogging down

Hello, It's time for a carb rebuild. Sounds like your accelerator pump diaphragm is shot. Rebuild the carb or replace with new or rebuilt carb and you should be all set. Post back, let us know how it goes!

 

[LubeDude]

Re: still bogging down

Yep, my bet is on the accelerator pump too. Its only 18 years old.

 

[TwoBallScrewBall]

Re: still bogging down

I just rebuilt my 1988 2bbl, the accelerator pump was completely destryoed, the diaphragm was in three peices. I'd bet dollars to donuts that's the problem. It's an easy rebuild, my local marina had the complete rebuild kit for $22.

 

[jrl]

Re: still bogging down

Sounds like Ill be doing a rebuild, thanks alot guys, Ill let you know how it works out

 

[Jdeagro]

Re: still bogging down

jrl;<br /><br />does the boat accelerate correctly at a Slower rate than full throttle?

 

[Rhadley]

Re: still bogging down

What carb do you have? The merc 2bbl is notorious for this bog, and according to my book, later versions (1987+) increased the accelerator pump capacity by 100%. I am doing the same thing to mine.<br />Best pump price I've found is $40. Mine uses a rubber piston on a brass shaft. I'd like to get a newer version carb that isn't underdesigned, but they're so expensive.

 

[jrl]

Re: still bogging down

the boat does accelerate well at a slower rate, quite a bit slower though....thinking it could be something else?

 

[Striper Blues]

Re: still bogging down

jrl, I just went through this on my 3.0L OMC cobra. Bob suggested the accelerator pump might not be working correctly and he was right. It is easy to check. Remove spark arrestor/air cleaner and look down carb throat (you might have to prop open butterfly if engine is cold). With the linkage disconnected operate the carb to simulate full acceleration. When you do you should see the accelerator pump force a two streams of gas into throat on each side (for 2bbl). If you don't see gas spray when you open the carb full chances are you're accelerator pump isn't working properly. On my Rochester 2bbl it took less than a half hour to remove carb and replace accelerator pump. If you have to go to this extent you probably should throw in the whole rebuilt kit. Check it out, mine is purring now. Accelerates instantly everytime...

 

[jrl]

Re: still bogging down

Thanks for the info, I really appreciate the help, I will give it a check and hopefully a rebuild will fix my problem...its getting to be skiing weather.

 

[TwoBallScrewBall]

Re: still bogging down

On the rochester, you can do the accelerator pump with the carb still on the engine.

 

[msando]

Re: still bogging down

i have the same symptoms and just had it tuned up and a complete rebuild on same carb for $560.00. and now my w.o.t is at 3200 not 4600

 

[Westdevil]

Re: still bogging down

if your boat has points check them.

 

[Bondo]

Re: still bogging down

msando <br />Member # 42040 posted June 25, 2004 07:46 AM<br /><br /> i have the same symptoms and just had it tuned up and a complete rebuild on same carb for $560.00. and now my w.o.t is at 3200 not 4600 <br />

Bring it back to Whoever did it for you......<br />Something is Very Wrong.........