Force 85hp won't start

spike_87

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Nov 11, 2009
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I recently purchased a 1988 Bayliner Capri with an 85hp Force outboard. I took it out a few times and everything worked well. Then one day out on the lake it shut down cold from a full throttle. My first instinct was dirty fuel, but there was no sediment in the fuel filter. So it leaves me thinking that the fuel pump is bad. Does anyone know if the fuel pump should pump a full stream of fuel when you turn the motor over? Right now it will not pump a constant stream out of the outtake hose when turning the engine over. Any help would be appreciated, I need to know if this is a fuel pump problem do I need to buy a new one or buy a rebuild kit?
 

Stachi

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Re: Force 85hp won't start

I would start by checking if you are getting fuel TO the fuel pump....maybe a clogged fuel filter, possibly a broken fuel pick-up tube inside of your tank...squeeze your primer bulb and see if it gets hard...if not , look into your tank with a flashlight , and see if there is a hose laying on the bottom of the tank...common problem on that old a boat...let us know what you find
 

chitownborn

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Re: Force 85hp won't start

the fuel will pulse coming out of the fuel pump, on mine i take off the fuel line going to the top carb and give her a couple cranks, it should pulse and be about two to three inches high or higher
 

spike_87

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Re: Force 85hp won't start

Fuel filter is clean. I took the line off the carburetor and I can pump a good 2-3 inches out by using the bulb but when I try cranking the engine over it only dribbles out. I opened up the fuel pump and the diaphragm looks to be in tact but not really sure if you can tell if it's good just by appearance. It appears that these are vacuum fuel pumps, is this true?
 

jerryjerry05

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Re: Force 85hp won't start

Will it start after you pump it up? More info please.Any particualrs will help.J
 

JB

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45,907
Re: Force 85hp won't start

Have you been through the "Outboard won't start" post in the Engine FAQs Forum, Spike?

Check that out and let us know what you find there.
 

spike_87

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Re: Force 85hp won't start

It will not start after I pump it up but if I shoot fuel into the carbs with a squirt bottle it will run for a few minutes. I have been the "outboard won't start" forum but didn't find anything that exactly matched my situation.

Last night I pumped up the bulb and took off the line to the top carburetor it shoots a steady 2" steam of fuel out but when I crank it over it spits and sputters fuel out. Should fuel come out in a steady stream with force when I crank it over?
 

Stachi

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Re: Force 85hp won't start

post #3 answered your question,......it should pulse, you have a mechanical fuel pump and thats how they operate...IMHO , you have a fuel pump problem even though the diaphragm appears to be fine , there is more to the fuel pump than a diaphragm.....if you search the threads , you will find that there are check ball valves that do not agree with modern fuels and deteriorate.....good luck !
 

kend301

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Re: Force 85hp won't start

I have a force that did the same thing , 1 hr of running and it would run out of fuel , do you have a square or a fuel pump(single stage) or shaped like an 8 (dual stage) ? If it is like an 8 then fuel pressure should be constant flow , Mine turned out to be a streched diaphram. Make sure check valves are available prior to removal as some can not be reused
 

spike_87

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Re: Force 85hp won't start

It?s shaped like an 8 and it definitely does not have constant flow. I purchased the rebuild kit which included the diaphragm and gaskets but does not include the check valves. Where do I get these if I need them?
 

jerryjerry05

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May 7, 2008
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Re: Force 85hp won't start

If the check valves are still intact and not corroded they are still probably good.The diaphragms are probably bad.Make sure the compression is good.Bad compression no fuel.J
 

spike_87

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Re: Force 85hp won't start

What should the compression be? I really think the compression is fine because when it did run it ran great!
 

chitownborn

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Re: Force 85hp won't start

compression should be at least over 100 and should be within 10 percent of each other, like jerry05 said no compression no fuel, youre using the second & third cylinders to work the fuel pump, if compression is low on either cylinder fuel delivery will suffer hope this helps you out don
 

spike_87

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Re: Force 85hp won't start

Since I'm fairly new to boating, is there a safe way to run your motor at home? I've heard you can run it with a garden hose. Do I need some special equipment to do this or is it not recommended at all?
 

chitownborn

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Re: Force 85hp won't start

yep, you can buy a pair of muffs they wrap around the in takes on the lower unit, put them squarley on the intakes hook up the hose turn the water on and fire the motor up, just make sure after the motor fires you have water exiting the two **** holes on the middle of the leg, on mine it takes about thirty seconds to get water flow after motor has started
 

spike_87

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Re: Force 85hp won't start

thanks where can you buy the muffs? Walmart, Autozone? Or do I have to order them?
 

chitownborn

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Re: Force 85hp won't start

you can get them at walmart, but there a piece a junk, dont know about autozone, a marine place should have them or you could order them here on iboats, there not expensive, but get a good set of muffs you dont need them slipping off when the motor is running
 
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