94 johnson 25hp fuel pump

[cooperjd]

model J94teerc ( i think). is there a way to take apart and examine my fuel pump to tell if its any good or not? i'm new to working on outboards, any help would be appreciated. i'm having problems reaching full throttle, my boat suddenly won't do it, so i figure fuel pump or carb problem. my bulb works fine, and the screen at fuel pump is clean, and gas will spurt out fine when i squeeze the bulb. has new spark plugs, but i'll change them again to be safe.

 

[OBJ]

Re: 94 johnson 25hp fuel pump

Other things can be causing your problem other than the pump coop.<br /><br />Start with basics. Do a compression test on each cylinder and check the spark.<br /><br />Cooling system working OK? Engine isn't overheating?<br /><br />Knowing what kind of rpm your getting now would also help. Running on one cylinder will cut your rpm. Usually when it's an "all of a sudden" problem, it usually is ingnition related.<br /><br />Easy test for fuel supply, put some premix fuel in a spray bottle and take it with on the boat. At WOT, spray some premix into the carb throat. If the engine picks up, likely fuel flow problem. If the engine does not pick up, likely ignition problem if compression is good.

 

[rodbolt]

Re: 94 johnson 25hp fuel pump

some of the later jonny/rude tiny mite pumps used an orange rubber set of check valves that can and do fail. try blowing backwards through the pump, if you can odds are one or more check valves failed.<br /> if one did its IMPERATIVE to find any missing pieces.<br /> other than that its about waht OBJ says.<br />becareful when testing cause if your problem is a lack of fuel in the crankcase it will run lean, try to limit the high speed testing.<br />as far as dissasembling the pump just remove it and all the screws holding it together and its apart.<br />rebuild kits are avalible however if its bad I replace them.

 

[cooperjd]

Re: 94 johnson 25hp fuel pump

i will try and get a compression test done asap, also i will to spray some fuel mix into the carb and see if taht will help. i hear that a powerpack can get loose connections and cause problems, so i'll check that out too. quick question about checking the spark, am i just looking for a spark, or is there a way to test the intensity?<br />thanks