Boat power hesitates when trying to pull a skier up out of the water.

[theCaptn]

I just bought a 1990 Volante LTD a few weeks back. Last week was the first time I tried to pull a skier. When I went to give the boat a hole shot it hesitated and then went forward. Anybody have any ideas as to what could be wrong. Any feedback would be greatly appreciated.

Keith T. (theCaptn)

[phil]

Hi and welcome! Carb is certainly suspect. When you initially get on the throttle, you should get a squirt of fuel from the accelerator pump. I would verify that your indeed seeing this shot of fuel when you initially hit the throttle.  What carb is on there? Do you always get a stumble on hard acceleration?

[Mike Harry]

I've not yet had to give full throttle to pull up even a skier. I usually run about a quarter to half throttle for a second or two probly open the back 2 on the Carb if needed.but I am in no way a "pro" at pulling.

Is everyone else stabbing full throttle to pull up a skier?

[phil]

Heck no, we don't even punch it when we barefoot.

[Mike Harry]

If its a Carb, and your pushing to full throttle out of the hole,  I don't think it'll ever work that way. I've never tried it, but I'm coming off a fresh build so I haven't pushed it hard yet anyway.

[brandon]

If it is a carb motor, and you put it in gear and then try a hard acceleration and get a hesitation, it is the accelerator pump in the carb. 

[Midskier]

a 20 year old boat only owned for a few weeks ........... it could be anything
with a new used boat I typically start 2 the prop and work my way towards the engine
b4 expecting anything to be normal
clean no ding prop
good strut bearing
propshaft alignment
trans fluid
engine oil
raw water impeller
fuel filter(s)
replace worn hoses
cap rotor wires plugs - electronic ignition if not already installed
set timing

carb, does it squirt? easy enough to check WITH THE ENGINE OFF

too many unknowns to condemn the accelerator pump @ this stage

and having to use full throttle to get a skier up is also way too much to

Dan T

[skiboatdriver]

I would ask the previous owner when the carb was rebuilt last.

[theCaptn]

It is the accelerator pump. I was lucky enough to run into guy who works at a local marina over the labor day weekend.  Thank you to all for your responses.

[Joel]

My boat very recently started to stumble / hesitate at 1/4 to 1/2 throttle.  At WOT she's off to the races!    Starts just fine when she's cold, but a little more effort is required after the engine has warmed up... occasionally acts like its flooded, but not all the time.  No overheating - range is 150 - 160 F.

No one has looked at my carb in over 3 - 4 years other than me tuning it per some instructions I found on the internet on "How to tune a Holley Carb"...  Not rocket science, but I have no idea of the internal workings of a carb      What is an accelerator pump & what is involved in replacing it??

Any ideas, suggestions, comments on where to start are welcome!

Joel

[Midskier]

Joel, the accelerator pump is a small mechanism on the primary half of the carb / front of the linkage side.  While the boat is on the trailer take the spark arrester off , disconnect the throttle linkage and stick a screwdriver in to open the choke butterfly, then move the throttle arm forward by hand while looking in the primary barrels  and you should see a squirt of fuel. Study the linkage and you'll see how it works and how it is adjusted.  However I'd first replace the water separator

Dan T

[backfoot100]

Joel,
Sounds like you may need to tweak a couple things.

First off, what Dan said. Fuel filter/water seperator replacement.
Then adjust the acc pump arm. The pump arm is right in front of the throttle linkage on the bottom of the primary float bowl like Dan said. There's a small spring and nut on the arm that you tighten/loosen to set. Adjust the pump arm so there is zero slop to the pump diaphram on the bottom of the float bowl. If that pump arm has a little wiggle to it when you touch it, you can tighten it up a little bit. Just don't over-tighten it or you limit the travel of your diaphram. You can do this non-running on the trailer. Then the slightest movement of the throttle should get a shot of fuel out of both pump nozzles located under the choke plate.

Then take it out on the water, warm it up and put it in gear, idling so the engine is loaded. Adjust each idle mixture screw to get the highest RPM. The final setting should be someplace around 1 to 1 1/2 turns on each screw. You may have to readjust the idle RPM on the throttle linkage as you do this.

Then hook up a timing light and verify your timing is still on. Should be 8-10 BTDC.

As long as the points, plugs, cap, rotor and wires are good, this should fix your stumble.

[RonT]

Joels boat only gets mechanical attention when it goes to the reunions, this is why he volunteers his boat for tech demonstrations, he wanted to learn how to re-pack a stuffing box which we did. But I noticed the shaft was pulling the stuffing box down & suggested we align the engine while we were at it. (raised the front mounts a full 6 turns, aft 4) (While doing this I also noticed the fuel filter appeared to be original, he thought it might be) So I would start there...just a thought.

[Joel]

Thanks guys!  And Dan is correct...  the fuel/water separator is old and Dan is giving me some well deserved ribbing      That is first on the list to replace, but I doubt it is the root of this particular problem - of course, I could be completely wrong   

Its not the ONLY time the mechanicals get attention, but it is the BEST time, when the "brain trust" is assembled with lots of knowledgable eyes!!    As it turned out, it was the perfect item to have a tech session on since the packing gland appeared to be in good shape.  The root cause of the packing not sealing correctly was the shaft alignment was WAY WAY WAY low and wearing on only the bottom portion of the packing.  Probably contributed to additional vibrations and premature wear of the strut bearing since it was not centered through the shaft log nor the strut.

Thanks again to Ron & Dan for showing us how the shaft alignment is done, correctly, step by step and WHY its done this way...  We even used the special American Skier Brand feeler gauge - $1 bill - to measure the gap on the shaft coupler.  One on one with hands-on is the only way to learn how something is done and I know everyone in attendance learned a lot... especially me.

Joel