Force 50 hp outboard won't start

[C-Dogg]

Hi all, new to the forum, bought my first boat near the end of last summer, an '85 Bayliner Capri with a Force 50 hp outboard. Boat and motor seemed to have been maintained well - you can eat of the motor it is so clean. Ran well last fall, and I had it winterized and stored indoors. Brought it out a couple of weeks ago after the storage place 'summerized' it. I got fresh gas/oil, took it out once and it ran fine. The next day, I was out with my son, puttering around just above idle making headway speed for about 10 minutes. Tried to open it up, and the engine died. Had to get a tow back to my dock . I thought it might have just been flooded, but two days later now it cranks but still won't start. I am moderately handy but I don't know diddly about boat motors, could use some guidance on where to start trouble shooting? The one time last fall when it wouldn't start, the issue seems to be the gas can was not venting properly - it got all sucked in and I think the vacuum stopped the flow of gas. I checked that this time and that doesn't seem to be the issue. Boat/motor are at my camp in southern Maine. Any thoughts would be appreciated!

 

[jerryjerry05]

Do a compression and then a spark test.
Both cylinders the same compression?
Spark on both?
Possible the flywheel key has sheared?
The squeezie pumped up till it gets firm?
Post the results.

Checking for a sheared flywheel key.
Remove the plugs, turn the flywheel until the mark on the flywheel lines up with the timing mark above the carb.
Then insert a screwdriver in the top plug hole and see if the piston is out as far as it will go.

 

[C-Dogg]

Thanks for the suggestions Jerry, I will be working on it this Saturday, will let you know what I find.

 

[Jiggz]

The great divide is whether the problem is fuel related or electrical. In your case, since there is only one carb the fastest way to find out is with the fuel spray test. Using a spray bottle, try spraying fuel mix directly into the carb while cranking it over. if it starts or even coughs (like trying to start) then you can tell it is most likely a fuel related problem. Otherwise, if it won't fire at all then you can tell it is a spark or electrical problem.

If it is fuel related, install a clear fuel filter between the fuel pump and the carb inlet. Just use a G2 Fram fuel filter costing less than $5. All it is is for troubleshooting purposes. After installation, prime the primer bulb until the clear filter is full and the primer bulb gets firm. Try starting again and if engine will not start, the problem is with the carb. Remove the carb bowl, and make sure the float is not stuck. Clean it thoroughly especially the needle port. Check make sure the float is moving freely and not sticking. Since the engine used to work before, there is no reason to make adjustments now just cleaning. Before putting it together, test the operation of the float and needle valve. Use a clean fuel hose to connect to the fuel inlet tube and slowly blow into it while manually raising the float with one hand. When the float reaches horizontal you should not be able to blow into it meaning it closes the needle port as required. And when the float is below horizontal you should be able to blow into it again.

On the otherhand, if the motor starts after the fuel priming steps discussed above but dies as soon as the clear fuel filter is emptied, then the problem is upstream of the filter, i.e. fuel pump, leaky hose or even clogged fuel lines.

 

[C-Dogg]

Ok, got back to the lake this morning, it started right up on the first turn of the key. I had planned to do some maintenance anyway so I took it out of the water and changed the gear oil. Put the lower unit in a barrel of water, and agin, it starts right up. Then, time for compression check. Both cylinders at ~105 psi. I had bought new plugs, using the model number from the Seloc guide, but when I opened the new ones, they were gapless. So I checked the gap on the old ones and put them back in. This time, engine cranks put does not start. I checked plugs for spark, that looks fine, so I don't think it's an electrical issue. Gas appears to be getting to the motor, I can smell it (and see it in the barrel) when I try to start it. What's next to check, the carb bowl like Jiggz mentions above?

 

[C-Dogg]

I will be back up to work on the boat tonight, if anyone has any thoughts or suggestions, let me know!

Thx,
Colin

 

[C-Dogg]

One more question regarding Jiggz suggestions above - to do those carb adjustments/cleaning, does the whole carburetor need to be removed? And if so, do I need a rebuild kit with new gaskets, etc, to put it back on? Thanks!

 

[Davee3]

One more question regarding Jiggz suggestions above - to do those carb adjustments/cleaning, does the whole carburetor need to be removed? And if so, do I need a rebuild kit with new gaskets, etc, to put it back on? Thanks!

Some times carb cleaning is easy & other times Stubborn I am on 4'th try on an OMC fully disassembled . This time sitting in a bowl of sea foam & see some new black spots that did not come out with other tries. I have heard at times eve nthe weltch plugs have to be removed. -to get at some drilled passages Funny it was running great for several weeks & now? Have installed a new fuel filter . You will likley get away without new gaskets

 

[jschneiter]

The great divide is whether the problem is fuel related or electrical. In your case, since there is only one carb the fastest way to find out is with the fuel spray test. Using a spray bottle, try spraying fuel mix directly into the carb while cranking it over. if it starts or even coughs (like trying to start) then you can tell it is most likely a fuel related problem. Otherwise, if it won't fire at all then you can tell it is a spark or electrical problem.

If it is fuel related, install a clear fuel filter between the fuel pump and the carb inlet. Just use a G2 Fram fuel filter costing less than $5. All it is is for troubleshooting purposes. After installation, prime the primer bulb until the clear filter is full and the primer bulb gets firm. Try starting again and if engine will not start, the problem is with the carb. Remove the carb bowl, and make sure the float is not stuck. Clean it thoroughly especially the needle port. Check make sure the float is moving freely and not sticking. Since the engine used to work before, there is no reason to make adjustments now just cleaning. Before putting it together, test the operation of the float and needle valve. Use a clean fuel hose to connect to the fuel inlet tube and slowly blow into it while manually raising the float with one hand. When the float reaches horizontal you should not be able to blow into it meaning it closes the needle port as required. And when the float is below horizontal you should be able to blow into it again.

On the otherhand, if the motor starts after the fuel priming steps discussed above but dies as soon as the clear fuel filter is emptied, then the problem is upstream of the filter, i.e. fuel pump, leaky hose or even clogged fuel lines.

I know this is an Old post, but this is the easiest to follow troubleshooting steps Ive seen EVER. I'm hoping I can't get my 90 force going again. It was working flawlessly one day at home on the muffs. Then the next day, nothing.

 

[cyclops222]

Running on water muffs ? Has damaged & overheated motors. To where parts on the motor become damaged. Been there and done it. When a phone call stopped me from watching the muffler move off the inlet ports.

 

[jerryjerry05]

Those muffs need to be taped in place.
Duct tape won't stick to a wet drive, put it on when the lower is dry.
Was at work and running a new motor test.
Things going good then I notice no water in the exhaust.
The yard guy unhooked the first part of my hose and hooked another so he could wash a boat. Got to watch.

 

[alldodge]

closed