2hp Johnson two much gas

furpy

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Hello there...I have a 2 hp Johnson that I am rebuilding.....new coil.....carb rebuild kit....and new packing on the lean rich high low needle valves...gapped the points at .020....my problem is...it gets too much gas.....I open it up full throttle and it just chugs....I close both needle valves all the way and still gets too much gas...what?s going on?...When I close the fuel line, it will finally start to run fast and then die from fuel starvation.....put new float....needle and seat.....new packing on the needle valves....the packing was two rings of what looks like cork or something...and the one washer that was some kind of plastic....the needle valves looked like they were in good shape....
 

GA_Boater

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Welcome aboard.

Did you set the float level and check the the float and needle aren't sticking?
 

oldboat1

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'84 model, but probably representative: http://www.iboats.com/Carburetor/dm/cart_id.930066599--session_id.303364649--view_id.1545030 Think I would note the float configuration (possible to install upside down). Also the float needle, valve, washer and the little wire clip for the needle (goes over the float arm). Let's see -- also the choke flapper in the front of the carb throat. May be closed/flooding. Gasket at the bottom of the nozzle also important for proper fuel feed. There are six lead shots that need to be in place on the model shown (replace if any were removed).
 

F_R

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It is impossible for it to get any gas if you truly have both needles completely closed unless gasket #21 in oldboat1's link is missing or leaking.

EDIT: Well also any lead shots that may be missing below the fuel level, as oldboat suggested.
 

furpy

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Hello...finally learned how to reply here...update....found that the main jet needs to have a cork ring around the top to seal....it was missing....put it on and now it runs good at full throttle only....and it will race way too high on rpms....kept adjusting high speed needle...could not throttle down without it killing....can?t get it to idle....all lead shots are in place....float is level and not upside down....might change spark plug....haven?t yet.....gave up on it today....how about the water pump? It is spitting small amounts out through those four little holes along with exhaust. I?m using 91 octane...no ethanol....50-1 ratio....
 

furpy

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1976 Johnson Outboards 2 - 2R76S CARBURETOR section
This is the exploded view of my carb....very similar to the Evinrude...
Hmmmm...did not paste what I wanted.
 

oldboat1

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The gasket is # 21 at the bottom of the nozzle, as mentioned earlier.

The domed fitting (#6 "plug") at the top needs to come off to clean the idle passages. The needle at the top is the idle adjustment needle (air/fuel). Initial setting is 1 to 1 1/2 turns open.
 

tomhath

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Regarding the water pump, they don't spray much, more like a fine mist. But if you haven't changed the impeller and lower unit oil you should just to be sure. The impeller might pump okay until it breaks apart and causes big problems.
 

furpy

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The gasket is # 21 at the bottom of the nozzle, as mentioned
The domed fitting (#6 "plug") at the top needs to come off to clean the idle passages. The needle at the top is the idle adjustment needle (air/fuel). Initial setting is 1 to 1 1/2 turns open.

I will remove the dome cover....but will be a leap of faith for me....don?t like doing that....will use small chisel or screw driver?....just kind of pry up on it? Then just tap new one in after cleaning?....it looks to me as though the gasket 21 goes on top of the main jet....it is a cork ring about 1/4 thick....just sits atop the jet and when you put the top of the carb back on, it pushes down on the cork gasket causing a seal around the top of the jet, thus keeping extra gas from getting sucked into the Venturi?
 

furpy

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Check reed valves?
Not quite sure how to check reed valves, but compression seems to be ok when I pull the rope....also....the person who worked on it before me had reversed the mounts that hold the fuel tank assembly.....it caused the flywheel to rub on the top housing...
 
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Bonaventure

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That is true, but if their condition can cause too much fuel entering the crankcase. The screws holding them in place could be loose, the reed valve gasket could be leaking. Reed valves are between the carburator and the crankcase.
 

hardwater fisherman

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I will remove the dome cover....but will be a leap of faith for me....don?t like doing that....will use small chisel or screw driver?....just kind of pry up on it? Then just tap new one in after cleaning?....it looks to me as though the gasket 21 goes on top of the main jet....it is a cork ring about 1/4 thick....just sits atop the jet and when you put the top of the carb back on, it pushes down on the cork gasket causing a seal around the top of the jet, thus keeping extra gas from getting sucked into the Venturi?

My manuals say to drill a 1/8 inch hole 1/16 of an inch deep. And then pry it out with a punch. That is how I do mine. If you drill it out, do not go too deep. And make sure you get any metal shavings that may have fallen in the carb. To reinstall the manual says to put the convex side up and tap it in with a square ended punch. You can add a little sealant to the outer edge of new plug before tapping it in. However you decide to remove it I would stay away from the casting of the carb to avoid chipping or marking it. Also be careful if you use any sealant. You do not want it dripping or falling into the carb.
 

furpy

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My manuals say to drill a 1/8 inch hole 1/16 of an inch deep. And then pry it out with a punch. That is how I do mine. If you drill it out, do not go too deep. And make












sure you get any metal shavings that may have fallen in the carb. To reinstall the manual says to put the convex side up and tap it in with a square ended punch.
You can add a little sealant to the outer edge of new plug before tapping it in. However you decide to remove it I would stay away from the casting of the carb to avoid chipping or marking it. Also be careful if you use any sealant. You do not want it dripping or falling into the carb.



Ok thanks....I will do that! Then I can see if there is some gunk in there...there has to be....it runs too lean now.
 

furpy

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Reed valves have nothing to do with compression in the cylinder.




Not quite sure how to check the reed valves....on a two cycle, there is only intake/ compression....power/ exhaust....will google that...
 

jbuote

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Still pretty new, and haven't had to check my reed valves, but as I understand it, One way to check them is to hold an index card or similar in front of your carb.
​If the card or paper or whatever you use, blows away from the carb, then the reed valves aren't closing properly.. Carbs should only suck air/fuel in really..

​The reed valves are behind the carbs in the intake manifold. They are supposed to open to let the air/fuel mix into the crankcase when piston move upward to top of it's stroke (creating vacuum in the crankcase), then they close so it doesn't come back out the carb when piston is moving down (creating pressure In the crankcase)..

​There's no valves in the cylinder top like a car (or any 4 stroke).. 2 stroke has holes in the cylinder walls towards the middle/bottom.. One set to let fuel/air into the combustion chamber and another set to let exhaust out..
​When the piston moves up past these sets of holes, they're blocked off from the combustion chamber, which is why the reed valves have nothing to do with your compression readings..

​Again, Still pretty new, so it's possible I have something not quite right in the above statement, but that's how I understand it to work at this time anyway..

​For whatever that may be worth... lol
 
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