Honda outboard stalling

[Mougly]

Hi all

My 1991 Honda 7.5 HP 4stroke outboard motor stalled today while I was out for a sail, it started fine and was running well then suddenly it stalled, when I started it again it started and idled fine, but as soon as I opened the throttle it stalled again...

I checked the fuel tank which had enough fuel in it....the bulb seemed to have pressure in it....and oil level was fine, It did get me back to the marina but only on idle speed.


Has any one had this problem? what would cause this?

 

[Ted]

I had a slightly older Honda 7.5 hp 4 stroke with a similar problem. It would idle fine but when I tried to increase the speed, it would almost die. When I removed the cover from the top of the motor, it ran perfectly fine at idle and full throttle. Try running your motor with the cover removed. If it runs better, then you probably have a hole in the exhaust tube or other exhaust leak under the cover. What happens is that exhaust gasses are leaking into the enclosure created by the cover and starving the motor of oxygen. When you remove the cover, a greater volume of fresh air is allowed to enter, and the motor should run fine again. It drove me crazy trying to figure out why this was happening but now it all makes sense. This may not be your problem but it's worth a try. You will have to replace the exhaust tube.

 

[Franklin]

I had that problem. Replaced spark plug and the problem went away.

 

[r.oril]

If the gas is not fresh, replace it and add some additive to clean the carb. Changing the plug is a good idea also as Franklin said.

 

[Mougly]

I did have new fuel and I know it's not an exhaust leak as I had the cover off and it did the same thing as before.
I will change the plugs and add an additive as suggested and see what happens.

Cheers

 

[kloudie1]

Sounds like a plugged high speed jet or passage in the carburetor..
My old 7.5 Honda (1979) had ignition points and would do that when the points got bad, every couple of years. Wasn’t the points as much as it was the piece that rubbed on the cam that opened the points..when that wore, the points gap would slowly disappear and finally get to the point (?) where it would idle but not run any faster. You’ve probably got electronic ignition, but that may have to be checked out if the other leads don’t fix the problem.

 

[alexco38]

Remove the thermostat housing and clear out any debri. May be the thermostat is stuck slightly open and the engine is running too cold. It drove me crazy for a long time.

 

[petersea]

ok here is my 2 cents. I would go with bad gas or a dirty carb. Clean the carb reset the jets, change the plugs and change the fuel lines on the engine also. The ethanol gas is junk and has no shelf life so that untreated fuel will go bad in less then 30 days. I also run a "maintenance" dose of stabilizer and cleaner all the time. Take the bowl off the carb and I bet you will find little "pebbles" (yellow /gray in color) If your hose from the tank to the engine is older then five years replace it also.This is the ethanol destroying your fuel lines. All the above work should only take you a hour to do.I have a mid 80's model 7.5 and except for the gas issue it is a great little engine.

 

[garyc]

Change your fuel filter.

 

[Johnt1594]

Ethanol

Practically every owner of small outboard engines in our area has had a problem lately with stalling. I have a 10 year old 5 hp Nissan that always started and ran perfectly. I had to have the carb removed and cleaned twice last year and a new carb kit put in this year plus replacing the fuel hoses and bulb. The mechanic always finds water and grit in the carb - no matter how fresh the fuel. Apparantly the ethanol in the fuel has been cleaning the inside of the tank and engine parts and dumping the accumulated varnish in the carburator.
I suggest draining and cleaning the tank, not storing fuel for more than one month, replacing the jets in the carb and running the engine dry if you store it for more than one week.

 

[Joe]

Did you open the vent in the gas tank?

 

[Mougly]

Thank you all...I've taken some of the advice and removed and cleaned the carb, replaces the plugs, the fuel, and even checked the fuel pump...after that the motor still had a problem and it seemed to have gotten worst until I removed the carb again and readjusted the float....in fact we had to do that twice.....this worked and the motor seems to be running dreat now...I hope it will last at least till the end of September when my boat comes out of the water and starts it's winter hibrination (early season)

 

[Mougly]

Well its that time again, the ice on the lake is finally gone and preparations are beginning for the new sailing season.... unfortunately at the end of last year the motor had the same stalling problem and now that I have it off the boat I am thinking about rebuilding the carb and fuel pump...I am also hoping that some one with a similar problem could sagest other things to do so that the motor does not stall especially during some of our nasty storms when you need the motor most.

 

[petersea]

Change all the fuel lines on the engine as well. Make sure the fuel bulb keeps pressure they do go bad so maybe replace it (relace the whole line from tank to engine). If you still have problems with engine stalling when giving it fuel try pulling choke half way out and running engine like that until you get back to shore but it would appear you need the carb rebuilt. Good Luck !