Boat runs great in Driveway, but stalls on water

Hello,
I have a 1994 Four Winns Horizon 180, with an OMC, 5.0 Cobra engine. I've had the following work done recently:

• Rebuilt Carb (Twice)
• New Starter
• New Fuel Pump
• New Fuel/Water Separator
• Sparkling clean Flame Arrestor
• Fuel Fill replaced with new stainless steel one
• Fuel Tank emptied

When I start it in the driveway at home (both in neutral and in gear), it runs great. I can rev it just fine in both scenarios. However, when I get on the water, it still revs in neutral great, but the minute I push down the throttle it stalls. If I baby it, I can go just fine at about 5 mph. But if I tried to give it any more gas, the thing stalls on me. Also, I could be going at 5 mph, but if I go over someone's wake, it threatens to die as well.

Any ideas?

Thanks

Re: Boat runs great in Driveway, but stalls on water

The difference is in the water the engine is under load --- on the muffs it is not under any load.

If you have not changed the prop ----> increased pitch etc.,

I would run a compression test and check the timing. For a 5.0 Litre to be that low on power the timing chain may have jumped a tooth or two.

Have you owned this boat long ? When did it last run good ?

OFM

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If the boat is not sinking or on fire, Relax

Re: Boat runs great in Driveway, but stalls on water

What do you mean by "If you have not changed the prop ----> increased pitch etc."?

Also, how can I do a compression test? I'm still learning all this new stuff, but I do learn quickly. All those things I mentioned in my original post I can now do myself.

I've only owned the boat a few months...got it from a buddy of mine. Prior to me taking ownership, it had sat in the elements for two years (winterized).

It has run okay twice, and that's it. The rest of the time, it has been a headache.

Re: Boat runs great in Driveway, but stalls on water

Does it miss when you try to accelerate or does it just bog and die ?

Compression test ---> pull the spark plugs, remove the coil wire from the distributor cap and sit it close to a metal object but not the carb, get a compression guage ( rent it, buy it , borrow it from a parts store ), screw it into the plug holes one at a time and crank the engine until you see the guage move at least three times, repeat for each cylinder --- read the pressure from the gauge ---- should be 120-lbs or more.

The engine could be old and tired and someone over-propped it

If it misses under load when you try to accelerate than that is a whole different scenario.


OFM

-----------------------------------------------------------
If the boat is not sinking or on fire, Relax

Re: Boat runs great in Driveway, but stalls on water

Apollo75 said:

Does it miss when you try to accelerate or does it just bog and die ?

Click to expand...

It just bogs and dies...As soon as I push the throttle down, it chugs a couple times, then just stalls out.

I'll try out the compression test. One more quick question...I pull all spark plugs at the same time, correct? And sorry to ask, but what is the "distributer cap"?

Re: Boat runs great in Driveway, but stalls on water

I would look at a compete ignition tuneup first. You did not mention anything about a tune-up involving plugs cap rotor and timing set, also timing advance check having been done recently. It is best to get the manual for your setup and work from that as far as values and procedures for this.

Could be as simple as ignition timing or distributor not advancing the timing. In neutral an engine will not care much where the timing is for it to rev ok.

I am not sure what kind of ignition you have, but if the distributor has centrifugal timing advance you can check that action easy enough. Take the cap off and try to turn the rotor gently. It should move a little bit in the direction of the rotation and snap back once you release it. If this action is acts stodgy then the advance may not be happening at the right time and the engine will have driveability problems under load. Again, I am not sure exactly what type of distributor and ignition system you have, the advance may not be in the distributor but controlled by the ignition control box.

A compression test uses a pressure gauge with a fitting that screws in the spark plug hole. The engine is cranked over without starting and the gauge shows the compression. The test is done with all spark plugs out, throttle wide open, and with a good battery and starter. If done on a warm engine it is best, but if cold there are what is called wet and dry tests. If cold and you crank it over that is a dry test. Do it again after squirting in some oil and that is the wet test. If the engine is still warm from the last run then there usually is no need to do the wet test.

Re: Boat runs great in Driveway, but stalls on water

We will not be much help if you do not know how an internal combustion engine works along with all the related parts for your engine. Search the web and read. Then read some more ---> I still do it everyday

The prop on a boat is the load --- if someone changed it and it is too large or has too much pitch ----> moves more water on each revolution it will overload your engine. You will not be able to pick up speed.

If the engine is low on power with the right prop the same thing will happen ---> not enough power to accelerate.

Added : Good job Maclin

Best of luck

OFM

-----------------------------------------------------------
If the boat is not sinking or on fire, Relax

Re: Boat runs great in Driveway, but stalls on water

Did you rebuild the carb or someone else?

Re: Boat runs great in Driveway, but stalls on water

What is the model number of your drive/engine. 1994 is the year when the Volvo OMC joint venture started so you mat have the old or newer set up. May possibly make a difference in the diagnosis.

Also, what is the history of this boat? Did you just buy it? Has it ever run right? Why has the carb been rebuilt twice?

mrtommy03 said:

And sorry to ask, but what is the "distributer cap"?

Click to expand...

Also, if you don't know what a distributor is I might suggest getting friend to help you. Knowing what a distributor is would mean basic engine mechanical skills to me. You may be over your head on this.

Re: Boat runs great in Driveway, but stalls on water

If the engine will rev in neutral without stumbling or too much hesitation, then I doubt the carb is the issue. First, I'd check to make sure the outdrive isn't bound up keeping the prop from spinning. Don't know the Volvo specifics, though.

Re: Boat runs great in Driveway, but stalls on water

haulnazz15 said:

If the engine will rev in neutral without stumbling or too much hesitation, then I doubt the carb is the issue. First, I'd check to make sure the outdrive isn't bound up keeping the prop from spinning. Don't know the Volvo specifics, though.

Click to expand...

First off he has an OMC not a Volvo and he also states:

"When I start it in the driveway at home (both in neutral and in gear), it runs great"

I also disagree that it isn't a carb issue. You could have a very lean condition and still rev it in neutral.

Re: Boat runs great in Driveway, but stalls on water

Okay, so is the general consensus to start with a Compression test?? I'll get that done today.

If it is running lean, which I've also heard that from a ford mechanic who is familiar with these types of engines, then what should I do? Is there some kind of adjustment that can be done somewhere??

Re: Boat runs great in Driveway, but stalls on water

The compression test is a good start.
Also a full tune up as mentioned above.....I really think you need a mechanic to go over it and do the work.

Re: Boat runs great in Driveway, but stalls on water

On a previous boat i had a GM with a Cobra outdrive that displayed a very similar problem. Ran great at home. Even ran great when I got to the lake. After about 40 minutes on plane I throttled back for a no wake zone. (5 mph) Went to throttle up and she coughed and died. Restarted fine. Went forward and she died. Got towed back in took her home and she ran fine. A little more digging and I found a collapsing fuel supply line. It was old and sucking closed. Without a load enough fuel got through. But with the lower end in the water no power.

Re: Boat runs great in Driveway, but stalls on water

mrtommy03 said:

Hello,
I have a 1994 Four Winns Horizon 180, with an OMC, 5.0 Cobra engine. I've had the following work done recently:

• Rebuilt Carb (Twice)
• New Starter
• New Fuel Pump
• New Fuel/Water Separator
• Sparkling clean Flame Arrestor
• Fuel Fill replaced with new stainless steel one
• Fuel Tank emptied

When I start it in the driveway at home (both in neutral and in gear), it runs great. I can rev it just fine in both scenarios. However, when I get on the water, it still revs in neutral great, but the minute I push down the throttle it stalls. If I baby it, I can go just fine at about 5 mph. But if I tried to give it any more gas, the thing stalls on me. Also, I could be going at 5 mph, but if I go over someone's wake, it threatens to die as well.

Any ideas?

Thanks

Click to expand...

I have the same problem when i first purchase my Boat i have a OMC V6 3.8 L Engine. i have two .. everything you just mention was just like my boat.

I have two New REBUILT CARB. i have BOTH intake manifold and clean it out.
Replace OIL and SPark PLUG.

i have Replace BOth Waterpump with new House and impeller and plate. reseal both of them realllll good..

I will put everything back ASAP.

i will tell you what happen.
Also maybe the expert here is rigth about the timing.. you should really check that out. because on a regular car if the timing is to LOW you car is not going any where. and if it is to Advance.. i think thats also no good.

I will do all this distribution and spark plug replacement this month. i will let you know what happem.. if it work for me it should work for you..

YOU should really check your compression test on your ENGINE. it will tell alot about your ENGINE...

GO to AUtozone. the Compression test kit is only $60.

Re: Boat runs great in Driveway, but stalls on water

Gary H NC said:

The compression test is a good start.
Also a full tune up as mentioned above.....I really think you need a mechanic to go over it and do the work.

Click to expand...

I agree...However when I took it to the shop and said, "do everything you need to do to get it lake ready", I spent a crap load of money, and well, I just don't have enough to take it back and get raped financially again. The last time I picked it up from the shop they told me it was all ready to go. I later found out that their "lake test" was only run it in the driveway for an hour. They said it ran great! Well no ****, but under a load it obviously still has issues.

I will start with the compression test. How can I check to see if the fuel line is collapsing??

Re: Boat runs great in Driveway, but stalls on water

Go here and see Item #12:

http://forums.iboats.com/showthread.php?t=288430

Best way to check for fuel system problems is with a fuel pressure gauge. It's covered in the article above.

Re: Boat runs great in Driveway, but stalls on water

Okay, so I did the compression test and all looks good there.

I also popped off the Distributor cap and noticed a little bit of corrosion on a couple of the connectors (not sure of the correct terminology here). So, I ordered a new distributor cap and rotor. I also ordered a new Coil. After I get those installed, I'll take it out again on the water.

Stay Tuned...

Re: Boat runs great in Driveway, but stalls on water

Okay, so I did the compression test and all looks good there

Click to expand...

What were the numbers?
Did you do it by the book, like this service bulletin explains?
http://www.boatfix.com/merc/Bullet/97/97_25.pdf

How can I check to see if the fuel line is collapsing??

Click to expand...

Look at it, but if one is flat, it's because of something else being wrong, not the fuel line. In reality, if the fuel line were to collaps, then it's not marine rated and shouldn't be on the boat anyway.
THIS TEST will tell you if there is something wrong with the boats fuel system up to the fuel pump.

Re: Boat runs great in Driveway, but stalls on water

I also popped off the Distributor cap and noticed a little bit of corrosion on a couple of the connectors (not sure of the correct terminology here). So, I ordered a new distributor cap and rotor. I also ordered a new Coil. After I get those installed, I'll take it out again on the water.

Click to expand...

If you keep randomly replacing parts long enough, it's possible that you'll sooner or later get to what's wrong.

Logically troubleshooting the problem usually gets it fixed a lot quicker and cheaper ......

Did you even look at the link I posted above, in the earlier post?