Fuel leaking when motor tilted.

[hardwater fisherman]

Early 80s 40 hp. Serial # 7207752 Canadian made. When tilted fuel runs out of the carb throat. I know some fuel dripping is "normal". If I pump the primer bulb with the motor tilted it pours out. If I prime it while the motor is down it fills the bowl like it should and the the bulb gets hard and the carb bowl stays full ... Then if I tilt the motor up fuel drips out quickly. Also running at WOT the motor surges a little. And if in a high speed turn the motor really surges. The motor had the carb rebuilt in a local shop back in 2017 and I have had no issues until now. I think maybe a float or float needle problem? It has the float bowl on the side of the carb which I do not have any other like it. Also I added electric start to it and the carb is hidden behind everything. Any help would be nice thanks.

 

[Chris1956]

That is normal. Floats only seal the inlet needle, when they can float (hence the name). When you tilt the motor, the floats cannot float normally.

Why are you pumping the primer bulb with the motor tilted?

 

[hardwater fisherman]

I was pumping it just to see where the fuel was leaking. I do not have any motor that loses all the fuel in the carb while tilted and it only started recently so I do not think its normal to have to refill the carb after motor has been tilted maybe I am wrong. I understand that some leakage is normal. If I tilt it up to fish and then put it back down after there is a slick of fuel on the water and I need to pump the bulb before starting. It did not leak at all that I know of until the last couple of trips that is why I asked. I do a lot of fishing with electric motor and have used several different motors that I tilt and leave up for hours. And I fill the carb bowl once only and I am good for the day.. This motor was the same except for the last couple times out.

 

[Chris1956]

Most/all of my outboards leak fuel when tilted. Some more than others. My I6 even had a fuel catch basin under the carbs.

Floats and inlet needles do not last forever. They are maintenance items. Perhaps yours's are worn out.

Can you leave the motor tilted down, when fishing? That saves you from rebuilding the carbs.

 

[hardwater fisherman]

I started leaving the motor down and just running the electric motor at a higher speed. And I ran the carb dry before tilting it at the end of the day. My main concern was the high speed surges that started af ths same time I noticed the carb leaking. I'm not sure if it's related or not.

 

[Chris1956]

When you say surges, do you mean that the motor runs up to full speed upon initial acceleration, and then slows a bit, an then runs back up to full speed?

 

[hardwater fisherman]

It is tiller throttle and if I hold it wide open it gets up to around 24 mph and then after running wot for a while the boat loses speed and I can here the rpms drop off and decreased speed for several seconds. Then it suddenly returns to the 24 mph again. Last year I had the same issue when using one of my tanks because the hose was pinching at the motor in a turn. I have 2 tanks that have around 20 feet of hose each as the tanks are up front. Next time out I think I will try a shorter hose and tank nearer to the motor. The motor starts and idles very well and does not stall. If I get up on plane and just keep it there at a cruising speed it runs nicely.

 

[Chris1956]

It does sound like fuel delivery issue. Pump the primer bulb when at full speed. If she maintains top speed, that confirms fuel delivery issue. If moving the tank closer doesn't fix it, you may want to rebuild the fuel pump. They do not last forever.

If primer bulb collapses, you have fuel tank vent issue or other restriction.

 

[hardwater fisherman]

It will not be for a couple weeks but I will let you know what happens.

 

[hardwater fisherman]

The fuel delivery problem is solved. It was the bayonet connector. I have 2 tanks and 2 fuel lines and I was running on one side for the first few trips and I had no problems.. The last few times running from the other tank . So I brought a 3rd 3 gallon tank to try today. When I removed the connector from the motor it fell apart. The inner part stayed with the motor and the gasket and ball bearing fell to the floor. Switched it over to the good connector and the motor ran great again.. I had 2 old OEM connectors that fell apart already and the one that fell apart today is 1 of 2 that I bought last year. I have serval OMC male and female connectors so I think I am going to convert it..