Outboard issue

[Has Been]

1986 Merc 35 hp . Starts hard but OK,runs 1/4 throttle kind of OK. Give it the gas, gets up on plane & runs OK for about 30 seconds , & dies dead. Starts OK . then repeats. Carb ISSUE? Float stuck? Fuel pump? Non ehtanol fuel the last couple of tank , but eth was used some prior.

 

 Any insite? Thanks in advance.

[McDragon]

Is the vent plugged on the fuel can?

[Has Been]

I have two tanks & it does it on both , but I will check again, thanks.

 

 My wife was born in Kingston.

[steelydan]

carb issues. float or needle valve

[Chas0218]

Does the throttle control box have 2 levers one for fast idle and the other for engaging the forward reverse/throttle? If so make sure the fast idle stays down while engaging in gear. I have seen this happen with the older mercs and kills the motor.

Sent from the awesomeness of Chas!

[rlconverse]

i seen and heard of a couple issues like this  how old is your fuel line from the tank to the engine? my father had an issue this spring with his 89 mariner the problem was that the fuel line had dry rot and was sucking air   good luck!

[CaptSpike]

As stated above lots to check. Check the easy stuff first. Fuel lines, filters, separaters and vents. I had problems earlier this yr that I thought was fuel related and did a search on ethonol fuel. looks like there can be some issues mixing back and forth between the two. You may want to do an internet search on mixing the two fuels. I don't remember the specifics as I used ethonol fuel only so it didn't apply to me, but I do remember seeing something about it.

 

Good luck finding the fix. Hopefully it is a simple fuel line replacement.

 

Spike

[ERABBIT]

 

 Fuel pump ?

 

Do all as you stated above but have someone pump the primer as you go from idle to .25- full throttle...... if it runs OK then the diapham in the fuel pump is almost shot time to rebuild  the fuel pump......

[McDragon]

To eliminate the onboard tanks try a portable tank. This will isolate the issue as to boat fuel system or Engine.

 

Ethanol breakdown in the tanks can be an issue. Also, in older boats the fuel line were designed for regular gas, not ethanol. The ethanol causes the rubber hoses to deteriate, which can lead to collapsing, or the rubber breaking down and causing a restriction.

[Has Been]

Put rebuild kit in carb & cleaned as good as I could. Needle valve did not seem to be working properly. Was leaking gas out of carb when I pumped it before , now it's not. Changed all hoses  from  carb to hose connect on motor. Put back together & test ran, Adjusted, Started & idled great in driveway w/the muffs. Will give it hell tommorow.

 

 Thanks to all for the input.

[Has Been]

Took it out bassin this morn & gave it heck on the lake. Seemed to run good as new.  I'm happy.