1992 johnson 25 hp electric start runs like crap.

[kelplin]

So i just put a new starter in, rebuilt the carb, and it started and ran pretty good, still had the sneeze at low rpm's but ok. the bulb was having problems staying hard... so i drove it for about 5 min, ran good then started running like ****. checked spark, got spark in both cylinders, new plugs, new gas/filter/gas additive. still ran like crap. bought a new fuel line plug engine side and then the bulb would stay hard, but when it ran the rpm's would go up and down and then all the sudden clear out and run ok for a min then rpm's up and down. so i bought a fuel pump rebuild kit and rebuilt the fuel pump, now the bulb wont stay hard at all and will only run if i spray gas into the carb. so i put the pump back together wrong, so im gonna go try and fix the pump but i need to check the timing... could that be it? and it will not idle at all. im at a loss, i have a lot of money and time invested into this for it not to work. also the spark plug on the top cylender keeps getting all carbon-ed up every time i run it. im not sure how to put the fuel pump back together, the spring came out before i could see where it was. i need help. thanks nick ps this is the rebuild kit, http://www.marineengine.com/parts/a...g&title=+Sierra+Marine++Fuel+Pump+Kit+18-7800 what is the star looking round part? that is not in my fuel pump?

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

update, so i took the fuel pump off again and rebuilt it and now i get pressure in the bulb, it starts hard and doesnt idle for ****, but it runs and you can troll around at about 3 mph... when you give it wot it goes for a sec, then bogs down and then kicks back up but only for seconds then bogs back down... im stumped, it ran ok before the carb was rebuilt by a marine mechanic. it also turns over really hard?

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

anyone have a clue where to start? i would like to get it running correctly....

 

[Daviet]

Re: 1992 johnson 25 hp electric start runs like crap.

Try pumping the primer bulb when it is acting up, if it picks up and runs properly, you still have a fuel pump problem.
Have you tried adjusting the low speed needle valve to try and smooth out the idle?

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

ya i have tried pumping the bulb when it does the revving up and down thing, no change. the bulb stays hard. ya i have adjusted the low speed needle valve many times, it doesn't change the way it runs... i have good spark in both cylinders, but i pulled one of the plug wire off and started it, it ran the same, then i did the same for the other cylinder and it also ran the same. It seems like it is running rough and only on one cylinder. Could it be the timing? i also need to check the compression but i know it has compression cause the starter is brand new and turns over pretty slow. If i pull the plugs out it turns over real fast, i think the batterie has **** the bed.

 

[Haffiman]

Re: 1992 johnson 25 hp electric start runs like crap.

You seems to be jumping all over the place without getting any result.
Start with a link & synch.
Loosen the roller screw between carb and the ignition advance cam under the flywheel.
Start the engine and let it run at lowest possible rpm, only using the timing advance to adjust rpm.
Start with the carb screw about 3 turns out, then adjust IN 1/4 turn at a time until engine reach max rpm without altering the timing advance. If/when engine sneeze and cough, go out 1/2 turn.
Repeat a couple of times, with engine at lowest possible rpm.
Then advance the throttle and align the roller with the mark on the cam and tighten the screw. Sometimes better to just slightly let the mark pass the roller to get a smoother transition.
Put engine in forward gear(let it run, shift into gear and stop) and give full throttle.
Adjust the stopper on the link from carb to the vertical shaft (port side) until carb is 99,9% open. Be sure not to over-open the carb.
Go back to idle, shift into neutral, start the engine and do a test run AT SEA not on muffs!!!!

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

im not sure where the screw is for the ignition advance cam.....

 

[Haffiman]

Re: 1992 johnson 25 hp electric start runs like crap.

im not sure where the screw is for the ignition advance cam.....

It is no screw for ignition advance, ignition will be advanced when throttle is opened either by remote or twisting the handle. If the cam roller screw on carb is loose, rpm increase will be by ignition advance only.
PS:
If on remote control hook-up, disconnect the throttle cable and use the idle stop screw at the exhaust cover to increase/decrease idle.

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

So i made some videos of this motors issues..... sorry bout the sound i didn't realize you cant hear me most of the time http://youtu.be/PN3VMjZ6s6Y http://youtu.be/6Dibt4bBdrY http://youtu.be/302p9zdP828 http://youtu.be/EwYpACY5njg
running finally, this is after almost killing my car batteries and putting mix in the cylinder and carb, and a new plug http://youtu.be/EjUK0qlkNTo i should have put it all the way down into the idle spot on the vid to show it just stalls out before you have a chance to put it into gear. thanks ahead of time for any responses.

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

so i have pulled the boat out of the water, there is milky stuff(water getting into the bottom cylinder) so i have a bad seal? head gasket? or is the piston, ring and cylinder shot? I took the bottom plug all the way out and the motor started right up. i have issues....

 

[Cofe]

Re: 1992 johnson 25 hp electric start runs like crap.

so i have pulled the boat out of the water, there is milky stuff(water getting into the bottom cylinder) so i have a bad seal? head gasket? or is the piston, ring and cylinder shot? I took the bottom plug all the way out and the motor started right up. i have issues....

Water getting into the lower cylinder could be either a head gasket, or the exhaust baffle plate gaskets. I had a similar problem with a 1990 25 and replaced those gaskets then the motor ran fine.

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

Water getting into the lower cylinder could be either a head gasket, or the exhaust baffle plate gaskets. I had a similar problem with a 1990 25 and replaced those gaskets then the motor ran fine. but was it really hard to turn the motor over??

 

[kelplin]

Re: 1992 johnson 25 hp electric start runs like crap.

Water getting into the lower cylinder could be either a head gasket, or the exhaust baffle plate gaskets. I had a similar problem with a 1990 25 and replaced those gaskets then the motor ran fine. but was it really hard to turn the motor over??