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slabbuster
04-04-2005, 10:53 AM
Look I have question for anyone who knows anything about motors,lol. I am tired of taking my boat to the boat shop for minor tune ups so I decided to try it myself. I am having trouble with my boat getting off to a fast start. I have changed the spark plugs, put fuel additive in the gas tank, and sprayed carberatur cleaner in the carberatur, and put a new fuel filter on. It almost seems like the motor is slipping.

Moose1am
04-04-2005, 11:14 AM
Motor Slipping? That is what I am keying in on. Sounds like the prop is either caviting or slipping. If the prop won't turn with the shaft it's slipping. You can check the prop and make sure that it's tight on the prop shaft and that the nut is locked into postion with a key pin. Also check the blades of the prop for wear and tear. Worn or broken blades can cavitate. Cavitation occurs when low pressure on the back side of the blade while it's under the water creates air bubbles from the pressure drop. Water normally holds the air is solution but when the pressure on the dissolved air is decreased the air can form bubbles. Since props are designed to work in water not in air you can loose thrust when your prop is cavitating. Also it will make a lot of noise, well lots if you are a nuclear submarine trying to remain unheard. By going deeper the subs can get rid of the cavition as the water pressure increases as you go deeper.

I would bet that its the nut on your prop that needs to be tightened a bit. Unless your motor still is using shear pins but most modern motors don't use them anymore from what I understand.

Make sure that you have water running out fo the engines so that you know that the water pump is working. If you have not had the water pumps rubber impeller replaced in a few years you may want to have that checked as part of your routine maintainence. Also have the thermostat checked to make sure it's still in good shape ever few years.



Look I have question for anyone who knows anything about motors,lol. I am tired of taking my boat to the boat shop for minor tune ups so I decided to try it myself. I am having trouble with my boat getting off to a fast start. I have changed the spark plugs, put fuel additive in the gas tank, and sprayed carberatur cleaner in the carberatur, and put a new fuel filter on. It almost seems like the motor is slipping.

SweetHomeAlabama
04-04-2005, 11:17 AM
If you think there is slippage, it may be your prop. A quick trip to the prop shop will show one way or the other.

If you want to clean the carbs, the best way is to take them off, take all of the plastic and rubber off, take out the jets, and soak it in Berrymans Carb cleaner (the 2 or 3 gallon bucket with the dipping tray) for 2-3 hours. Rinse with water and let dry.

Put in new plugs and reset the timing with freshly cleaned carbs. A timing light will be necessary.

The best way to avoid having to clean the carbs is to disconnect the fuel line when you are putting the boat back on the trailer. After the boat is on the trailer, let the motor run till it cuts off due to lack of fuel, then try to crank it a couple of more times. This will insure that all of the fuel is out of the carbs.

Barnacle Bill
04-04-2005, 11:19 AM
Look I have question for anyone who knows anything about motors,lol. I am tired of taking my boat to the boat shop for minor tune ups so I decided to try it myself. I am having trouble with my boat getting off to a fast start. I have changed the spark plugs, put fuel additive in the gas tank, and sprayed carberatur cleaner in the carberatur, and put a new fuel filter on. It almost seems like the motor is slipping.

Need more info. What kind of motor is it? When you give it the gas, what does it do? Have you changed props recently? Does it idle smoothly? Have you added any weight to the boat? If you have a tach, what is you RPMs at WOT?

papasage
04-04-2005, 11:46 AM
put a mark on the prop alinge with the hub run it and see if it mooved .
spraying carb cleaner in the carb want do much . they usealey git clogged at the high speed jets . might need a rebuild . check this site for information.http://www.themarinedoctor.com/cgi-bin/YaBB.pl

Moose1am
04-04-2005, 11:54 AM
Hey Sweet:

I have always run the fuel out of my engine after unhooking the fuel line from the engine. That seemed to work as I never had any carb problems for many years. Only after about 20 years did I find that the carb needed to be rebuilt.

But someone told me that unhooking the fuel line and running the engine until it stops would not remove all the fuel from inside the carb bowl?

Does anyone know what the truth is? My experience tells me that it does not hurt the motor to run the fuel out and the store it like that all winter long. I do shoot some fogging oil into each spark plug hole for long term storage as that helps to protect the cylinders and pistons during the long cold winter months when the boat is stored outside under a canvas cover.



If you think there is slippage, it may be your prop. A quick trip to the prop shop will show one way or the other.

If you want to clean the carbs, the best way is to take them off, take all of the plastic and rubber off, take out the jets, and soak it in Berrymans Carb cleaner (the 2 or 3 gallon bucket with the dipping tray) for 2-3 hours. Rinse with water and let dry.

Put in new plugs and reset the timing with freshly cleaned carbs. A timing light will be necessary.

The best way to avoid having to clean the carbs is to disconnect the fuel line when you are putting the boat back on the trailer. After the boat is on the trailer, let the motor run till it cuts off due to lack of fuel, then try to crank it a couple of more times. This will insure that all of the fuel is out of the carbs.

Barnacle Bill
04-04-2005, 12:39 PM
Moose, you were told correctly. When you disconnect the fuel line and let it run until it quits, there is still some fuel in the carbs. However there is NO fuel in the cylinders and now have no protection. (lube). This can cause scoring of the cylinder walls over a period of time.

Crappie Chatt
04-04-2005, 12:45 PM
Be careful running your engine without/out of water. You will ruin the impellers in the water pump. A can of 'Seafoam' gas stablizer is your best bet. Add it to your gas before you take it out fishin. You won't have to run it dry when done, in fact, it's better if you don't. A little preventive care will make your days longer on the water and not in the repair shop. Remember,,,, fuel at marina's just might be old, especially this time of the year. <*)}}}><

Barnacle Bill
04-04-2005, 12:48 PM
That Seafoam is some fantastic stuff. It helps keep carbon out and also is a fuel stabalizer. I've seen some old engines brought back to life doing a decarb with it.

Bassky
04-04-2005, 02:04 PM
Hey Sweet:

I have always run the fuel out of my engine after unhooking the fuel line from the engine. That seemed to work as I never had any carb problems for many years. Only after about 20 years did I find that the carb needed to be rebuilt.

But someone told me that unhooking the fuel line and running the engine until it stops would not remove all the fuel from inside the carb bowl?

Does anyone know what the truth is? My experience tells me that it does not hurt the motor to run the fuel out and the store it like that all winter long. I do shoot some fogging oil into each spark plug hole for long term storage as that helps to protect the cylinders and pistons during the long cold winter months when the boat is stored outside under a canvas cover.

Be aware if you run the gas out of the carbs you could score the pistons. Especially if you have more than 1 carburator. What happens is the top carb may run out of gas first before the bottom carbs, or vice versa, the engine still runs but there is no gas/oil getting into the cylinders. My dad used to do this until his Merc 50 started making some grinding noises, caused from him pulling the gas line off and letting the engine run until there was no gas in the carbs. This is what the mechanic said. So be aware of the problems you could encounter with multi carbs on your outboard.
Bassky
:)

slabbuster
04-07-2005, 08:00 AM
Thanks I appreciate the tips. To answer your questions IBNFSHN. THe motor is a Force 40 (mercury/chrysler engine). When I give to gas it is like rpm's are going up but thrust is not kicking in. The engine Idles smoothly and I have not added any weight. The Rpms go up to about 3 to 4. Also the boat was able to go 32 mph, but since I have had problems it only gets up to 27 mph once I get up to speed. It takes longer to get it up to max speed than it used too.

Barnacle Bill
04-07-2005, 11:36 AM
Thanks I appreciate the tips. To answer your questions IBNFSHN. THe motor is a Force 40 (mercury/chrysler engine). When I give to gas it is like rpm's are going up but thrust is not kicking in. The engine Idles smoothly and I have not added any weight. The Rpms go up to about 3 to 4. Also the boat was able to go 32 mph, but since I have had problems it only gets up to 27 mph once I get up to speed. It takes longer to get it up to max speed than it used too.

Yup, like someone else mentioned, it sound like you have spun a prop. Fairly common and any prop shop can fix it by re-hubbing it. You can verify this by putting a marks opposite each other on the inner and outer part of the hub. Take it for a spin until it does that again and then recheck the marks. If they are no longer lined up, thats your problem. That is a real common problem on 25HP Mercs. According to my prop man. its a poor design by Merc.

badbrad
04-07-2005, 12:02 PM
Who can tell me more about "Seafoam" I've not heard about it. Is it very expensive and do most marine dealers carry it? Also what is the application?

Barnacle Bill
04-07-2005, 12:07 PM
Who can tell me more about "Seafoam" I've not heard about it. Is it very expensive and do most marine dealers carry it? Also what is the application?

Its great! And most autoparts stores carry it now. Its used to remove and keep carbon out of your motors. I have seen old outboards brought back to life by doing a de-carb with it. It is also a fuel stabilizer so you don't have to worry about you gas sitting over winter, if you have one of those things each year.

papasage
04-07-2005, 05:37 PM
if the prop is slipping it can be rehubbed . i sent a S S prop to jacksonville fla. and had it re hubbed . there is a place in oklahoma city . am sure there is some near you . is pineville in Arkansaw. . a dealer could send it or tell you where to send it and they might have the equipment to do it

fiddlefarter
04-07-2005, 07:19 PM
There's a Prop Shop in Nashville. If you can't find something out your way, holler and I'll get their number for you. I'm sure there's one in AR somewhere tho.

Kokanee King
04-07-2005, 08:26 PM
this may be a problem that I am having too. When on a high speed the motor will give a sound like it was just put into nutral and the bout loses all forward momentum. I dont now if the prop is still rotating, because when I here that sound I pull back on the throtal. It happend on the last trip that I tock it out on it was fine in smooth water but not in the rough stuff. maybe I am just crazy.

Barnacle Bill
04-07-2005, 09:36 PM
this may be a problem that I am having too. When on a high speed the motor will give a sound like it was just put into nutral and the bout loses all forward momentum. I dont now if the prop is still rotating, because when I here that sound I pull back on the throtal. It happend on the last trip that I tock it out on it was fine in smooth water but not in the rough stuff. maybe I am just crazy.

Check it like I told Slabbuster a few posts up. Then you will know for sure.

papasage
04-08-2005, 04:40 AM
http://www.themarinedoctor.com/cgi-bin/YaBB.pl
http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi
this is 2 good sites . boat motor experts . the marine doctor is a mercuray teck . he also works on all other bran motors . i boats also have some good tecks . papasage

slabbuster
04-13-2005, 07:18 AM
ok thanks for all the excellent tips and pointers, but now the mystery is solved thanks to all of your help. So here is the answer to my own question. I was looking at my motor this weekend and saw a plate missing above my prop. It was a whole in my motor, so I went to the boat deal and ask for the part. I also asked if this missing would cause any problems. He told me yes and described exactly what was wrong with my boat. He said somewhat, lol, that this was for the exaust and and it was calavating my prop which would cause to have difficulty getting up and going. I'm just glad it was nothing major. thanks

JEFFRO
04-13-2005, 07:28 AM
Look I have question for anyone who knows anything about motors,lol. I am tired of taking my boat to the boat shop for minor tune ups so I decided to try it myself. I am having trouble with my boat getting off to a fast start. I have changed the spark plugs, put fuel additive in the gas tank, and sprayed carberatur cleaner in the carberatur, and put a new fuel filter on. It almost seems like the motor is slipping.
A PIN HOLE IN THE FUEL LINE WILL CAUSE IT TO DO THAT, I HAD THE SAME THING THING HAPPEN TO ME YEARS AGO , MY BOAT WOULD TAKE A LONG TIME TO PLANE OUT . TRIED EVERYTHING UNTIL A FRIEND TOLD ME TO REPLACE THE FUEL LINE . THAT SIMPLE FIX WAS THE ANSWER TO MY PROBLEM . IT MAY SOUND ELEMENTRY BUT IT ONLY COSTS A FEW DOLLARS TO ADD TO YOUR PROCESS OF ELEMINATION .

JEFFRO