Gas leaking woes- 1990 Evinrude 150

[steveb101]

I have a problem with gas leaking from front of motor when trailering with motor tilted up. I have gone through the carbs, installed new floats, needle valves, needle valve seats, all new gaskets, and still have the problem. I pumped the pressure bulb up after reinstalling the carbs, and everything seemed to hold fine with no leaks. I have a shutoff valve on the fuel line to the motor, and always shut off the gas when not running the motor. Upon arriving at launch for a test run, I noticed gas smell, pulled motor cover off and noticed gas dripping slowly from bottom of air intake box. Boat ran like a top, no gas leaks upon reloading on trailer, but leaking again when I arrived at home. Anybody have any ideas on what I might be missing here? Oh yeah, also the plastic float bowls were warped and I used a piece of glass and 120 sand paper to take the warp out of the gasket surfaces (a pointer I picked up on this forum- thank you!), and upon close inspection, there are no leaks from the float bowls, fuel line or fuel filter. The leaking fuel is evidently coming out from the front of the carburetors. I'm stumped and any experience with this or ideas would be appreciated. Are there float adjustments that have to be checked?

 

[boobie]

Re: Gas leaking woes- 1990 Evinrude 150

Check your reply to your post on Marine Engine.com.

 

[steveb101]

Re: Gas leaking woes- 1990 Evinrude 150

The info I received on Marine Engine.com was that this is evidently the way it is with these motors and if it's a problem, run the fuel out before tilting motor. The question I have is why the first two years I owned the boat this was never a problem? When it surfaced is when I did the carburetor work thinking the floats and needle valves were no longer doing their job. I read another post about a similar problem, and the feller said he ended up putting his old needle valves back in because they had rubber tips on them where the new aftermarket valves do not. Any more thoughts on experience with this would be appreciated. It seems to me there is way to much gas leaking out....it smelled up the whole garage after I parked it.

 

[Chris1956]

Re: Gas leaking woes- 1990 Evinrude 150

Perhaps when you turn off the fuel at the valve, the heat from the sun causes it to expand in the carbs and lines and overflow? Fuel is clearly not being "pushed" out of the fuel tank, right?

 

[Art Bernard]

Re: Gas leaking woes- 1990 Evinrude 150

Can't say why it's leaking out, but when you flush your engine after each use, let it run itself out of gas. This take care of the problem's symptoms untill you figure out the cause.

Art

 

[steveb101]

Re: Gas leaking woes- 1990 Evinrude 150

Correct, the fuel is not being pushed out from the built in vented fuel tank. I have a shut off valve between the tank and engine I always shut off when not using motor. The fuel expansion in the carbs did cross my mind, but the day I tested it was overcast and cool. I will run it out of fuel for now, but I have to say the low fuel warning whistle is hard on the ears when I do that. Does anybody know how to set the correct float adjustment? I replaced the floats which are identical to the old ones, and didn't know what to look for as far as adjustment.

 

[Auxlarry]

Re: Gas leaking woes- 1990 Evinrude 150

Could be the gasket on the air silencer cover is getting bad. Mine would do that every once in awhile until I changed the gasket and made sure the bolts were torqued properly.

 

[steveb101]

Re: Gas leaking woes- 1990 Evinrude 150

My next step will be to check the airbox gasket....I did put a new one in when I did the carb work, but it isn't sealing so maybe the cover is warped. Thanks for the input and I'll let you know how it turns out.

 

[Chris1956]

Re: Gas leaking woes- 1990 Evinrude 150

Don't run that motor dry. Some cylinders will run out of fuel first, and therefore will run out of lubricating oil as well.

I also recommend you not use the fuel shutoff. It is unnecessary and could cause the issue. After running the engine, the block stays hot for some time. This can cause the fuel to expand via heatsoak. Maybe this causes your issue? I think it worth a test.

BTW - If you are counting on the airbox gasket to stop a carb leak, you are fooling yourself.

 

[Auxlarry]

Re: Gas leaking woes- 1990 Evinrude 150

I have been told by numerous mechanics over the years to expect the carbs to leak when I tilt up after running on my V4 That is the reason a drain was installed on the air silencer base back to the block. If the gasket is good and all the bolts are installed in the air silencer cover you will not have the fuel/oil dripping into the engine.

Are the mechanics mistaken?

Larry

 

[boobie]

Re: Gas leaking woes- 1990 Evinrude 150

No !!

 

[Fed]

Re: Gas leaking woes- 1990 Evinrude 150

Leaking gasket or leaking drain hose.
I trim up with the motor turned to the starboard so the drain hose (port side) is on the high side and it doesn't leak. I promise to put a cable tie on that hose.... one day.

 

[emdsapmgr]

Re: Gas leaking woes- 1990 Evinrude 150

I'm with Chris on this. Don't run the engine till it runs out of fuel. You should have a VRO type fuel pump on that engine. When you disconnect the fuel line and let the engine run, the oil pump side of the pump will continue to work, and will pump your carb bowls full of oil. That's a problem next time you want to start the engine. Carb fuel leaks when the engine is tilted were common on the early crossflows, in the early to mid 70's. Not on these later carbs.

 

[steveb101]

Re: Gas leaking woes- 1990 Evinrude 150

It sounds from what I've heard not only on this forum that this is the norm on these motors, and the airbox and line to it are designed to catch the excess gas which WILL seep out when the motor is tilted all the way up. I picked up a new gasket, and will make sure the bolts are torqued and the line is tight, but I have to say this is poor engineering and another reason for me to look at replacing this motor with a Honda or Yamaha. Intentionally designing a motor to have raw gas vapor present at any time seems ridiculous at best. Thanks for all the input and safe sailing to everybody!

 

[Chris1956]

Re: Gas leaking woes- 1990 Evinrude 150

Hey Steve, Do you think Honda or Yamaha has a carb design that you can turn on it's side and it won't leak. If they do, I for one would be interested. Some chain saws have such carbs, but they are primative.

 

[steveb101]

Re: Gas leaking woes- 1990 Evinrude 150

I hear what your saying Chris, but I have owned 2 Hondas (still have one), and have never dealt with obnoxious gas vapors or smells on these motors whether they are tilted up or not. My brother-in-law also has a Honda 150, and said he never smells raw gas when the motor is tilted up. My beef is why would you design a motor to be tilted up and locked in that position, and recommend putting it in that position when trailering in the owners manual, knowing gas would leak out the carbs? It just seems like they could have had a better system to handle it and prevent the gas from escaping somehow. I'm not an engineer by any means, but other manufacturers do have it figured out, and hopefully BRP changed it for Evinrude and Johnson.

 

[boobie]

Re: Gas leaking woes- 1990 Evinrude 150

You have to remember that mtr is 21 yrs old. How old are the Hondas??

 

[steveb101]

Re: Gas leaking woes- 1990 Evinrude 150

My first Honda was a 1986, the one I own now is a 2000. No problems with either.