Carbs flooding on 100hp johnson

[Fishindan]

Hi! Just put new carb kits on both carbs of my Johnson 100. (J100STLCEM). Set the floats IAW the factory serv. mnl. After reassy. I did the blow trick, with the carb inverted. They seem to seal pretty well ,but will still bypass some air.(The old needle & seat seem to seal better). After putting them back on, when I pump up the primer bulb,if I pump until the bulb is hard, fuel comes running out of both. Question is, should this happen if they are primed too much and if so how to tell how much to pump the primer to avoid this. I feel that the float and needle should seat, however maybe the bulb has enough force, if pumped enough, to force in fuel.

 

[oldcatamount]

Re: Carbs flooding on 100hp johnson

When priming the motor, you don't really need to squeeze the bulb until it's hard, just feel a firm resistance that's all. It doesn't take very much squeezing to fill the float chambers and that's all you're trying to achieve.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

Thanks. Thats what I was kind of hoping to hear. I'm going to put them back together and try it again.
I think between learning how much to prime and how much fuel to inject with the solenoid, for cold starts, this should solve much of my cold start problems. Also the VRO has been disabled on my motor-is the pump I hear running when the key is turned on the old oil pump?

 

[emdsapmgr]

Re: Carbs flooding on 100hp johnson

You should be able to pump the bulb till it's hard without fuel coming out of the carbs. The needle and float should shut the fuel off when the bowl fills. Where is the fuel leaking from: the bowls or from inside the carb throats? Any chance you have plastic bowls on those carbs?

 

[Joe Reeves]

Re: Carbs flooding on 100hp johnson

As "emdsapmgr" states, you should be able to apply all the pressure on that fuel primer bulb you can muster without having the carburetors flood.

(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

That was my thought initially. Best I can tell fuels coming from throats. And yes they do have plastic bowls.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

Joe, thats exactly the way I adjusted the floats. Then when turned right side up, the float hangs down 1 inch from lwr edge of the mating surface ,per the mnl.

 

[jonesg]

Re: Carbs flooding on 100hp johnson

To confirm its gonna work as planned, put a peice of tube on the fuel inlet and blow through as you turn the bowl over, it should block off the air as the needle seats.

Over-tightening plastic bowls can warp the edges and cause a leak too, thats why he asked.

Whats that noise you hear running when the key is on, I wonder?
Follow the noise.

 

[emdsapmgr]

Re: Carbs flooding on 100hp johnson

Were your carb kits purchased from Bombardier, or were they aftermarket? You will find the plastic bowls will warp, or may already be warped on your engine. Their ability to retain their original shape is very poor-the older they are. You might want to put both of them on a pc of glass and check to make sure they are still flat. They warp so much, even the thick rubber gasket won't keep them from leaking. Most need to be replaced with new aluminum bowls. In addition to leaking fuel at the rubber gasket, they can leak air into the suction tubes, causing a lean running condition.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

Just ckd the one bowl that is still off. The longer sides are warped to the tune of .014. Where to I fine new bowls? I got my kits through Boats.net. The parts bag says its genuine Evin/Johnson parts. I think I'm going to reassemb. everything and inst the carbs. leaving the air silencer off this time and slowly pump the primer and see if I can positively identify where the fuels coming from. Just to let you know I had this problem before I started rebuilding the carbs. Just got the boat last year and only had time to run it twice. spent the summer on the the hull exterior and the trailer.

 

[Silvertip]

Re: Carbs flooding on 100hp johnson

Also the VRO has been disabled on my motor-is the pump I hear running when the key is turned on the old oil pump?

Did nobody see this???? Your engine should NOT be fitted with an electric fuel pump and NO -- the VRO pump is not electric and does not make noise in operation. Turn the key on and use your ears to determine the source of the noise. Follow the fuel line from the engine back to the tank. If you find anything in that line other than the primer bulb, it is probably and electric fuel pump. Dangerous to install one on a two stroke outboard. If there is an electric pump, that pump may have too high pressure and it is overpowering the needle and seat. The only other thing that would be running when you turn on the ignition would be a livewell or bilge pump. You need to do more checking on that noise and determine where it is coming from.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

Thanks Silvertip. I intend to just havent gotten there yet. I havent had the boat that long and am still learning it. The noise you hear when the key is turned on is coming from the center console where the fuel tank is. I am going to disconnect the fuel line @ the large fuel filter and turn the key on to see if fuel is being pumped. I was able to fix the warped fuel bowls by laying a piece of 280 sandpaper on a hard flat surface and slowly milling out the warp. Cant get .002 feeler guage under the edges now.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

Silvertip. This thing absolutely DOES have an electric fuel pump in the tank. Dont know why or how. You recommend disabling it or removing ,yes? Guess that should solve my flooding problem.
Like I said, boats new to me, but has had a few hands on it over the years. Some probably not as good as others. Like to thank all the great folks on here. God love you all!

 

[64osby]

Re: Carbs flooding on 100hp johnson

Did nobody see this???? Your engine should NOT be fitted with an electric fuel pump ..........

Great remote diagnostic Silvertip

 

[emdsapmgr]

Re: Carbs flooding on 100hp johnson

Swapping out the carb bowls is simple, but not very straightforward. Order two of the original carb bowl part numbers. The replacement parts you get will be aluminum. The replacement aluminum bowls are machined differently and use different parts, so you will have to do some converting. You will need to replace the 2 bowl drain plugs on each carb-different thread sizes. Also, you will find two of the jets in your old carbs (not the high speed ones) will not fit in the new bowls. You will have to replace those jets with the same size, but with correct thread size.

 

[Silvertip]

Re: Carbs flooding on 100hp johnson

The reason electric fuel pumps should not be installed on a carbureted two stroke is because of what you were experiencing. Assume you were under way and the engine caught fire and died. Chances are you wouldn't think to turn the key off so the fuel pump kept feeding that fire. Internal carb leaks can fill the engine with fuel and should you hit the key you get an explosion.. Your fuel injected car for example has an oil pressure switch that cuts off the fuel pump should the engine die and in some cases the ECM controls that function. Your carbed two stroke does not have that feature nor is there an easy way to accomplish that function. Get rid of the electric pump and install a standard fuel-only (non-VRO) pump.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

Will the fuel pump thats integral to the still intalled VRO unit be enough? And if I disable the elec. pump you think it will still draw fuel through or will it need to be rmvd?

 

[Silvertip]

Re: Carbs flooding on 100hp johnson

The fuel-side of the VRO pump was enough to run the engine originally and probably has more capacity than the fuel-only equivalent. Unless that side of the pump is actually bad, it will work just fine. If it is bad, replace it with a fuel-only pump.

Why would you leave the electric in the system. It creates resistance to fuel flow. Get rid of it. It is not supposed to be there in the first place.

 

[Fishindan]

Re: Carbs flooding on 100hp johnson

I'm going to have to see what kind of connections are @ the tank. Not sure how big a deal it will be to remove the pump and install standard type outboard fuel tank fittings.

 

[jonesg]

Re: Carbs flooding on 100hp johnson

If you switch back to VRO, many of us find it works good, be sure to use premixed gas/oil until you verify its drawing oil properly.
Before connecting the oil line , pump the oil bulb to purge the line of air.