Motor Running Rich?

[Salmonseeker]

The motor is a 2004 Johnson 50HP 2 -stroke.
I finished installing Boyesen Reeds over the winter. I adjusted the idle setting screw out 1/2 a turn according to the instructions. I believe the motor is running rich.

The motor smells of fuel when it is sitting and the plugs are wet. I am also getting a fuel and oil mixture coming from the air silencer. This is coming from the crankcase drain hose when the motor is tilted up.

If I try to lean the idle screw mixture more than it is. This problem occurs. After a WOT run, I will put the boat in neutral and the rpms will rise to around 1500. If I go any leaner the same will happen and will end in a lean sneeze which brings the rpms down and then begin to rise again. The only way to stop this symptom is to richen the carbs at idle to where they are set now.

Is there something I am missing?

Thanks, Jay

 

[Salmonseeker]

Re: Motor Running Rich?

Anyone have any ideas???

 

[tashasdaddy]

Re: Motor Running Rich?

link in sink

 

[Salmonseeker]

Re: Motor Running Rich?

I actually did it twice. The first time I forget to unhook the throttle cable. The second time I made sure I followed the instructions to the letter. I checked this about 10 times and everything seems good.

 

[iwombat]

Re: Motor Running Rich?

You may be flooding the carbs just enough to pour into the manifold and leak out into the intake. Have you taken a look at the floats?

 

[Salmonseeker]

Re: Motor Running Rich?

I rebuilt the carbs when I first got the motor. There was a resctriction in the main jet. This was 2 years ago. I adjusted the floats to the middle of the spec. I do not think this is the case because the carb throats between the carb and the silencer are always dry. There is no oil residue or anything.

It seems to me that it is just coming from the crankcase.

 

[iwombat]

Re: Motor Running Rich?

I'm beginning to sound like a broken record this week, but maybe you're leaking from the fuel pump into the pulse hole. Does the bulb stay firm for very long after pumping?

 

[F_R]

Re: Motor Running Rich?

I'll confess that I'm not familiar with those Boyesen reeds. But isn't there a lot of normal blowback through those things? Need a Boyesen expert here.

 

[Salmonseeker]

Re: Motor Running Rich?

I'm beginning to sound like a broken record this week, but maybe you're leaking from the fuel pump into the pulse hole. Does the bulb stay firm for very long after pumping?

I just checked what you suggested. I pumped the bulb and it stayed hard for 20 minutes. Just to be sure I also removed the pulse hose from the pump and squeezed the bulb. I also turned the motor over by hand about 10 turns. No sign of gas or oil from the hose or pump. It is dry.

Jay

 

[Salmonseeker]

Re: Motor Running Rich?

I'll confess that I'm not familiar with those Boyesen reeds. But isn't there a lot of normal blowback through those things? Need a Boyesen expert here.

I am not familiar with the Boyesen reeds myself, but I do know the intake throat of the carbs are dry. I would think if it was spitback there might be some oil residue on them.

I should also note that this problem seemed to be occurring last year with the stock reeds which were in perfect condition. It did not seem this bad though, but that was last year so I can't compare that accurately.

 

[iwombat]

Re: Motor Running Rich?

Well it was a hunch anyway. Fortunately, an easy to test hunch.

 

[Salmonseeker]

Re: Motor Running Rich?

Hey, I appreciate the suggestion. I am completely out of ideas.

I am beginning to think that maybe this motor just runs like this, but it does seem to be worse than last year. Otherwise the motor runs fine. It is a bit hard stating when cold, but I have heard some Johnson's are known for this.

Anymore ideas are much appreciated.

Jay

 

[Walker]

Re: Motor Running Rich?

Check your recirculation valve/valves. Not sure whether your motor has one or two.

 

[Salmonseeker]

Re: Motor Running Rich?

Where would I find the recirculation valve?

 

[Dhadley]

Re: Motor Running Rich?

If the motor has sneezed at idle it probably burned a reed tip(s). When the motor "sneezes" fire will actually come into the carb throat. That'll burn a fiber reed almost instantly. You'll need to check the reeds first.

Second, make sure the reeds are seating completely on the reed block. The best idea is to surface the reed block before you install the Boyesens.

Next, make sure the reed base gasket is on correctly. There is a short side and a long side (looking from the screw hole to each side).

Now, just a silly question but you didn't reuse the reed stop, right? Or any shims, right?

 

[Salmonseeker]

Re: Motor Running Rich?

I have heard about the sneezing burning the fiber reeds. It seemed to be running rich before the sneeze occurred. That was why I started to lean the mixture. Once it sneezed I richened the mixture back up. I hope I did not do any damage.

I did surface the reed blocks perfectly flat on a surface plate with 400 grit paper. When I installed the reeds there was a small gap about .005" between some of the reed tips and the gage. I was told this would be okay.

I did make sure the new gasket was on correctly.

No, I did not reuses the original reed stops or the shim.

This problem seemed to be happening mildly last year before I put the reeds in. The original reeds were in perfect shape. That is why I am not suspecting the reeds as the cause.

Thanks, Jay