2001 johnson 90 hp leaking fuel

[captmello]

Hi, new to outboards, just brought home my new to me, pontoon with a 2001 90hp Johnson.

The previous owner started it up for the first time of the season this morning to let me hear it run and allow me to do a compression check. We only ran it for a minute or so. It seemed to run fine, but I'm not used to 2 stroke outboards so I can say if it was running right or not. It smoked a lot but it had been fogged in the fall and I figured it was ok.

Following the Compression test, which showed all cylinders right about 125 psi, I went ahead and bought the boat.

So, when I got it home, I walked around behind the pontoon to find fuel running down the lower unit. I pulled the cover off the motor and it looks like is coming from the upper carb on the starboard side.

The fuel seemed to originate from about the center of this pic.

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What do you guys think my next move should be?

The other thing that has me worried is when I lowered the motor down, this sludge started running out or the exhaust. I'm hoping its just some residual fogging oil mixed with the water from running it earlier in the day.

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What do you guys think?

 

[DargelJohn]

Re: 2001 johnson 90 hp leaking fuel

Compression numbers are great.

Can't tell anything from the top pic, the lower pic is unburned fuel coming from the exhaust which is not a worry.

With the engine off, pump the primer bulb til it's hard and look for leaks. If it's leaking from the air box cover then you might have a stuck float valve. Time for carb rebuilds...

 

[captmello]

Re: 2001 johnson 90 hp leaking fuel

Thanks for the response.

I was thinking a stuck float as well. Is this a job for a DIYer? Is it standard procedure to rebuild all carbs at the same time? Are there special tools needed? I'm trying to find a manual...

 

[Chris1956]

Re: 2001 johnson 90 hp leaking fuel

Sometimes the floats will unstick themselves. Give it 24 hours and recheck. if you are going to clean and rebuild one carb, you may as well do 'em all. Foru carbs = four carb kits. They are avail lots of places, so you can shop by price.

 

[Chris1956]

Re: 2001 johnson 90 hp leaking fuel

manuals are avail at marineengine.com. Have the model number handy.

 

[captmello]

Re: 2001 johnson 90 hp leaking fuel

Ok, so I went out to try to get a closer look and find where the fuel is coming out.

I removed the Air Box from the front of the motor. there wasn't any fuel in it.

I proceeded to pump the fuel primer bulb to see if anything happened. right away I could hear a hiss.

The hiss was coming from here. The seal on this fuel box (separation chamber/distributer?) right at the tip of my screwdriver.

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I put a quarter turn on the screws and it seemed to seal up fairly well, but still hisses a little when I squeeze hard on the bulb.

With the motor tilted down, it didn't seem to leak any fuel. However when I tilted it up about half way, fuel started running out of what seemed like all the carbs. I couldn't pin down where it was coming from but it seemed like it might be coming from around the float bowl gaskets or from around the screws that secure the float bowl. But I can't be sure. I can be sure that it appears to leak evenly from each side of the motor and I'm pretty sure from each carb. The entire front of the motor is covered in fuel. I'm guessing every time the motor it tilted up, all the fuel is running out of the carbs, but I can't figure out where.

Help guys!!!

edit, just wanted to add that the engine has been run for a total of one minute this year after being in storage since last season.

 

[captmello]

Re: 2001 johnson 90 hp leaking fuel

Any Ideas?

 

[bob johnson]

Re: 2001 johnson 90 hp leaking fuel

mine have always leaked when tilted up..

one very commone leak spot is the brass ball used to plug up a float bowl passage...you can see them on the starboard side carbs, but you cant see them on the port carbs..

the gas usually seeps out of there..

with plastic carbs leaks are common, clean up the inside of the cowling and run and let sit, see if you can see any fuel leaking into the cowl...or leaking from your fuel component bracket.

I have been running my motor with these little issues for two years..... the drip drip drip leaks are BAD......but if it is like so slow you cant see it happening...it is just a messy inconveinence....

you could pull all the carbs and fuel brackets and install all new gaskets and rebuild the crabs and seal up those brass ball plugs!!!

bob

 

[ziemann]

Re: 2001 johnson 90 hp leaking fuel

Personally, I think you have 2 different issues. I think you have a float that is stuck open. Most likely as stated above, the vibration of the motor while running will resolve it and it will be fine. Get some new fuel through through the engine and it may likely clean itself out (fogging oil) and loosen up that float.

As to the second issue, I don't know. Obviously there is a diaphragm there that is brittle and is leaking. If tightening doesn't work, then you might have to tear it down.

As far as the carb rebuild goes, if you are forced to do it yourself, PERSONALLY I think you should save yourself the aggravation and someone else do it. It can be a pain to do. Look in a service manual and see you agree- it is a fairly in depth process...

 

[captmello]

Re: 2001 johnson 90 hp leaking fuel

Hi guys, thanks for the replies. I guess for now, I'm going to leave it alone and run the engine a bit and see if anything changes or gets better or worse. Like I said, the motors been sitting all winter and the previous owner didn't have a clue about the motor. He just drove it and had a marina "winterize" it every fall. I'm normally a DIYer and would like to be able to work on my own motor, but I also know my limitations.

I've got more questions, but will not add them to this thread. And btw, if anyone has any other comments about this issue please let me know. I don't want to be driving a bomb around the lake.

Thanks again.

 

[Chris1956]

Re: 2001 johnson 90 hp leaking fuel

If the vapor seperator is leaking air out, it will likely leak air in. I would think that would cause your fuel pump to suck air and force extra air into the fuel mix. It may even cause a fuel shortage.