185 evinrude fuel/running issues

Joes_yj

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Aug 13, 2012
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i have a 1984 evinrude 185 hp that ive been chasing a problem with, i got the boat and the head gasket was blown. replaced both head gaskets and now the boat runs good...sometimes. it has new fuel filter and fuel pump. i can not find any dry rotted lines or air leaks. the tank strainer is also clean. Now there is a smaller fuel filter on the side of the engine that the fuel flows through, this thing never stays full. it usually sucks down till its almost empty. is it supposed to stay full? the one on my smaller mercury out board always stays full. the boat will run good but is very hard to get to wot and is very picky on when it does. also surges alot if im giving to much throttle. any ideas? im thinking a air leak at the plastic fuel filter housing on the side of the engine . thanks
 

Bosunsmate

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Re: 185 evinrude fuel/running issues

you could try running it without that filter and checking tanks airvent
 

Joes_yj

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Aug 13, 2012
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Still having the same issue. the boat will almost plane out and then as soon as its about to level the motor dies all power, but stays running, primer bulb does not stay hard, after a few attempts it will take off and run but i can never hit it full throttle or it will die. I beleive its a fuel issue, i replaced the filter on the side of the engine and it helped but did not fix it. I also bypassed the water seperator. No change, im at a loss here, boat starts and runs fine some times it well run really good, other times not so much. What can i look for? to sum up ive done all this

Replaced fuel filter
Cleaned all three carbs
Replaced fuel pump
cleaned fuel tank strainer
bypassed water seperator
replaced a few fuel lines
 

Joes_yj

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Aug 13, 2012
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Still having the same issue. the boat will almost plane out and then as soon as its about to level the motor dies all power, but stays running, primer bulb does not stay hard, after a few attempts it will take off and run but i can never hit it full throttle or it will die. I beleive its a fuel issue, i replaced the filter on the side of the engine and it helped but did not fix it. I also bypassed the water seperator. No change, im at a loss here, boat starts and runs fine some times it well run really good, other times not so much. What can i look for? to sum up ive done all this

Replaced fuel filter
Cleaned all three carbs
Replaced fuel pump
cleaned fuel tank strainer
bypassed water seperator
replaced a few fuel lines
 

emdsapmgr

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Dec 9, 2005
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11,551
Sounds like your engine is using the VRO single fuel pump. Possible the fuel pump is weak. Weak pumps won't supply enough fuel to run the engine at WOT for long. The engine may consuming more fuel than the pump can supply. Once the fuel carb bowls are sucked down, the engine will slow until the fuel pump re-fill the carb bowls. You can do a test. When the engine starts to run poorly, have a buddy constantly prime the fuel hose bulb. This will force extra fuel into the carbs around the fuel pump. If the engine runs fine as long as you constantly prime the fuel hose bulb, you've got a fuel delivery problem. Possibly a weak fuel pump. Also, keep in mind that many of the factory fuel hoses originally installed inside the cowling are probably not ethanol ready. Original hoses will degrade and black bits of the hose can separate and migrate down into the jets of the carbs, possibly restricting them..
 

Joes_yj

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Aug 13, 2012
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i have not checked the vaccumm pluse, how do i go about doing that?


Emdsapmgr- The fuel pump is brand new, 500 dollar oem unit, The VRO unit has been removed and i premix the fuel. Ran better with new pump but not perfect. If you prime it while running it doesnt make to much of a diffrence, however when it does almost die out and you have to cut back and try and take off again, you need to prime it before doing so. Carbs are clean as well but im going to replace all the fuel line on it just to be safe. Do i need marine grade fuel line or will any fuel line work? Thanks in advance.
 

1983 ercoa 21'

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I have check them by temporarily installing a tee and using a vac gauge. More than anything check the vac hose to the pump for any kind of cracks. I'd also check things like the dip tube in the tank some are hoses and get old and crack and will suck air from top of the tank rather than picking up fuel.
 

emdsapmgr

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1983 has some good suggestions. In addition, pull the anti-siphon valve out and check it to be sure the ball valve can move freely. (does not have some debris stuck in the vavle.) If debris restricts the ball movement, it can restrict fuel flow, esp at high rpm's. If you get into replacing the fuel hose under the cowling, keep in mind that some of those hoses bend in tight radiuses. You can't use bulk hose in those applications. The factory has special part numbers for those heat-bent hoses. Get the specific factory hose part numbers in those cases.
 

Joes_yj

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Aug 13, 2012
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i pulled the tank Draw tube out last summer, its aluminum and clear, i will check the vaccumm pluse and line for it. The anti siphon valve was new when pump was replaced but i will double check it.
 

1983 ercoa 21'

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Something else to think about. It wouldn't be the first time a new part was bad. Have you checked fuel pressure?
 

emdsapmgr

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You have done a lot of work on the fuel side of this engine. Any chance that it's not running on all 6 cylinders all of the time? Have you checked spark on each cyl when it's acting up? Weak ignition components tend to fail once the engine warms up to normal operating temps.
 

Joes_yj

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I know its been a while but i put the boat away for the season. Now its starting to get warm again and i dont want any issues with this, ive had it. I replaced the fuel filter on the side of the motor(small plastic unit) helped out a good bit. she still struggles. Im ordering new fuel primer blub and lines, im going to check pressures and vacuum pulse when i pull the cover off the boat in the next week or two (hope fully).

Emdsapmgr- i assume its a fuel issue because the clear filter on the side of the motor(the one i replaced) pulls down to almost empty. i would think its getting air in it some where but can not find where, im going over this with a fine tooth comb. i will also run a compression check.
 

Fed

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My little plastic filter always looks a bit empty but it doesn't seem to cause a problem. I asked my outboard guy & he said don't worry about it they're all like that.
Check your fuel vent line to the fuel tank for partial blockages.
 

emdsapmgr

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The small white filter in the main fuel line to my 83 V6 engine does the same thing. You pump it up when first starting and the filter fills. Once it's running and sucks fuel, it does not appear to be full, but the engine runs just fine. I've seen the squeeze bulb fail. Check the ball valves in it and be sure the hose is connected the right direction. You might repl the fuel filter. As 83eroca suggested, be sure the pulse hose is not cracked or leaking air. The pump won't suck right if it is. (Also, if the compression is down on that pulse cylinder, the fuel pump won't work well.) Usually any fuel line air leak is accompanied by a visible fuel leak at the same place.
When fuel deliver is poor to an engine, it may run full rpm's for a brief period, till the carb fuel bowls empty. The engine will then go to idle till the fuel pump recovers, and it will run good briefly. This cycle will repeat over and over if it's a fuel deliver problem. What did you find when you checked for spark after the engine was warmed up?
 

racerone

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Need compression values.------Does spark jump a gap of 7/16" on all 6 leads ?
 

Joes_yj

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My little plastic filter always looks a bit empty but it doesn't seem to cause a problem. I asked my outboard guy & he said don't worry about it they're all like that.
Check your fuel vent line to the fuel tank for partial blockages.

Fuel Vent line is clear.
 

Joes_yj

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The small white filter in the main fuel line to my 83 V6 engine does the same thing. You pump it up when first starting and the filter fills. Once it's running and sucks fuel, it does not appear to be full, but the engine runs just fine. I've seen the squeeze bulb fail. Check the ball valves in it and be sure the hose is connected the right direction. You might repl the fuel filter. As 83eroca suggested, be sure the pulse hose is not cracked or leaking air. The pump won't suck right if it is. (Also, if the compression is down on that pulse cylinder, the fuel pump won't work well.) Usually any fuel line air leak is accompanied by a visible fuel leak at the same place.
When fuel deliver is poor to an engine, it may run full rpm's for a brief period, till the carb fuel bowls empty. The engine will then go to idle till the fuel pump recovers, and it will run good briefly. This cycle will repeat over and over if it's a fuel deliver problem. What did you find when you checked for spark after the engine was warmed up?

Im ordering new prime blub and hoses (cheap insurance any way.) i will check pluse, compression and spark hopefully in the next few days if i get some spare time.
 
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