1970 9.8hp dies when put into gear

[Steve613]

Hi everyone. I just picked up a 14’ aluminum boat with a 1970 Mercury 110 9.8hp. I can get it running in neutral, rev it up and down without issues. When I put into gear, it stalls.
I have read a few posts about this so far without any final repair solutions.
I also notice that the fuel connection at the motor leaks when I really pump the primer bulb. Is there supposed to be a seal or something in there?
Thanks in advance.

 

[tpenfield]

I just got my 1969 Merc 7.5 HP up and running after some re-build.

Revving an engine doesn't mean anything.

Stalling when going into gear . . . Make sure the engine is not idling too low. I think they are supposed to idle around 600-700 RPM. I tend to like 700 vs. 600. If that is OK and still stalling, the idle mixture setting may be too lean. IIRC, this engine has the Tillotson carb with the idle mixture screw just above the intake throat. Try screwing in 1/4 - 1/2 turn and see if that makes a difference.

Fuel fitting seal . . . yes there should be a seal within the fuel line fitting. Also keep in mind if you over prime the fuel system, fuel will over flow from the carburetor. Just be sure it is the fitting leaking and not the carb overflowing. I believe the fuel fitting for those engines is in short supply and a bit pricey if you can get them. Not sure if/how you can fix your existing fitting, if it comes to that.

 

[Steve613]

Update....
Took the boat out Friday, ran good around the lake for about 20 minutes. As I throttled down to approach the boat launch, motor stalled out. Tried to restart without success. Brought boat home and tried again Saturday morning. Motor started in lane way, brought to lake, couldn’t get started once in the water (it would only run for few seconds)
I have spark, and fuel no longer leaks from fuel line connector.

 

[tpenfield]

It sounds like you need a carburetor cleaning. Hard to say not knowing the history of the motor, but that what is sounds like