25 hp johnson running issues

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djchris

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I have a 1989 johnson 25 hp remote steer outboar.....i just picked it up from the mechanic after paying almost 1300 dollars and the **** thing still don't run right....here is what was done....new upper crank seal, case gasket, base gasket, impeller, rebuilt carb.

I picked it up last thursday and the thing wouldn't idle let alone run at anything except wot. took it back to the mechanic and he pulled the carb apart and found a piece of debris somewhere in the carb...said he didn't know where it came from but he knows it wasn't there when he put the carb back together the first time.....any ways he recleaned the carb and put another new base gasket in because he said it looked like it might have pushed out a bit. he calls me yesterday and tells me that everything is good now and that i can pick it up......

I take it to the lake and it started easily and idle great! left the dock and went wot and the thing wouldnt get on plane. so i stopped and lowered my pin and it seemed to do ok after that but than at wot the engine started surging like it was running out of fuel than catching back up and than running out of fuel again. now the thing wouldn't seem to idle very well but would some what stay running....i noticed if i throttled up the motor in neutral and held my hand in front of the carb it would smooth out and run ok....restricting air flow.....i brought it home and ran it on the hose and same thing...doesn't want to idle unless i have screw on the carb turned about 3.5 turns out and than it still isn't smooth. i pulled a fuel pump off my other engine and didn't affect it at all.....

does anyone have any idea what could be going on.....i don't really want to take it back to this guy he has had my boat for a total of about 3 months and though it does run better than it did when i took it too him it's still not right...had to take it back to him 3 times already.....
 
Surging at WOT indicates a fuel problem.......... incorrect adjusted float, high speed orifice plugged in the carb, fuel system air leak, fuel filter plugged, restricted fuel supply line, fuel tank vent or hose restricted, carburetor base gasket leak ......and the list goes on. This is why I do all my own work, that way I know what has been done so trouble shooting is easier. Who knows what that guy did or did not do?

For $1300 you could have bought another 25 that ran like a top. I would make the mechanic fix it for free now....
 
If you want to work on it yourself I would start with the easy stuff like making sure all fuel lines are good and air tight. Cost about 10 bucks to replace all the lines and put zip ties on the ends to insure a tight fit. Next I would take that carb apart and make sure it was rebuilt properly. It wouldn't be the first time I seen a so called mechanic mis adjust a float or just plane not rebuild the carb yet charged you for it.
 
well as far as taking it back to him...it's not gonna happen he has had it too long and i still have issues so i kinda told him off....i believe i just found the problem after a lil investigating of my own.....i took filter off the fuel pump if that what you wanna call it....the front part that has the screen in it...well there are some pieces that look like the lining out of a old fuel line....well the screen was disfigured and allowing the debris to get past and into the carb....so i am going to remove the carb and take a look...only thing is i am not sure how to get the carb off....i have to remove the starter bracket and can't really tell what bolts are what......

any idea on this?
 
Ok you need to replace all the fuel lines. What happens is the ethanol from today's fuel eats the inside of the lines of the old rubber that was put on those motors. So line replacement is a must. I also run ethanol free fuel in all my outboards.

I can walk you through getting the carb off and I have pics also I believe..... just give me a minute here ok : )
 
ok i dug in....i have the carb off.....all the fuel lines are new....i replaced those last when i started having troubles....what all comes apart in the carb? is my next question
 
Ok all you need to do is remove three bolts to get the starter, bracket and solenoid out of the way to get to the nut on the carb. First make sure power is disconnected. There is one bolt in the front #3 in the diagram (has a locknut on threads usually), one on the side #74 and one underneath behind the solenoid #47 that you will need an extension and a small swivel adapter to get at. That one takes a little manuevering to get at. The bottom bolt #47 in the diagram can sometimes just be loosened and not totally removed so the starter can be laid to the side. Do not unscrew the throttle advance stop on the side of the starter bracket, it is the threaded bolt that has a slot in it for a screwdriver with a nut on it (do not touch). There is also 2 small bolts that need to be removed from the throttle lever.


here is a diagram with the little bolts #34 and the throttle lever #31 that I am refering to https://www.boats.net/parts/search/BRP/JOHNSON/1989/TJ25ELCEB/CYLINDER%20%26%20CRANKCASE/parts.html
The three starter bolts are #3, #47, and #74 in the diagram

I have the same motor its just an 88' and have done this numerous times
DSCN6306.JPG
 
Ok lol....... I guess that was a wasted post. The carb is really easy, start by removing the 4 bolts from the bottom to get into the float chamber. Wait do you have a rebuild kit already? Or are you just wanting to clean it out?
 
just cleaning.....the mechanic said he rebuilt it but i believe i am getting debris in from what i stated on a earlier post....
 
Get some carb cleaner, guitar string and an air compressor to clean the carb. You will want to make sure all jets and orifices have a clear path and have no debri in them. The smallest piece can make your motor run like crap. And before you reinstall you will want to be sure all fuel lines are cleaned out or you will be doing this again and again trust me. Been there done that lol
 
I have to leave for awhile sorry..... wife is yelling at me. I will be back in a few hours to help again if you need it.
 
well i got the carb put back on and it's running.....a whole lot better might i add.....taking it to the lake for a test run tomorrow in the am!
 
ok well my idle is great! But it's still surging....going to try a new primer ball. the one i have is a cheap one....if that doesn't work im gonna pull the carb and recheck the float level even though the mechanic said it putt it at the highest point it can go......is there a easy way to measure this? maybe with a ruler?
 
Ok there is only ONE level the float should be at. There is NO highest level. Ok I couldn't find a pic of my 25hp carb but here is my 15hp carb off my 87'......... the carbs are virtually identical just smaller. The float should be perfectly parallel with the carburetor body when you have the carb upside down like shown in the picture. That is the correct float level.
DSCN5523.JPG
 
see thats what i have been reading.....the mechanic guy told me there is a gauge or something he uses and that there is a set of marks that it has to be within......i should have just checked it when i had the carb off saturday....thanks again for the help i will let you know how it works once i get a chance to get back to the lake prolly will be tuesday....
 
There is a gauge tester template that can be used but all it does it makes the float parallel to carb body. I find it a little odd that a so called mechanic would need this considering how easy it is to set it to the correct height. I literally set all my carb floats by eye and have never had an issue of any kind with float setting. If he has it set high when the carb is upside down then it will shut off fuel flow to early and it will not allow the carb to function properly.
 
all problems are fixed and the motor is running like new again! funny how something so dumb as a primer bulb can cause a major problem like that......now i just need a new prop(i took a chunk out of it yesterday during a test run...) and play with the motor setup a lil and i golden!

Again thanks for your help!
 

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