Logo
FULL SITE MENU

Trouble starting and run on

J

Jeepersji

New member
135 hp will start but have to put throttle way up for gas? Will a injection cleaner help? It also won't shut down good, knocks. Had tune up and carb work done 2 years ago. Gas problem?
 
yes you have a 3.0 l motor 2 barrel carb.

Tell your mechanic to go thru the fuel system form the fuel pickup thru the carb.

Then a tune up.

Post back when he's done if you still have a problem.
 
It's a I/0 on a 18 ft run about boat. Mercury. Was hoping just need fuel additive :( runs just after skiing when we shut it down to change people,it s hard to start and often won't shut Down without the run on knocking.
 
Sounds like it's flooding. Carb issue. Loading up at start so that's why throttle plates need to be open all the way to start, then time to shut offit's at idle loading up again and runs on afterwards IMO.
 
Is the transom of the boat covered with any black soot?

Hard starting the running on after shutting it down is usually cause by a rich fuel condition. The piston tops will be covered with carbon(from the rich condition) which will be hot enough to ignite fuel after the ignition is shut off.

Time for a Tune up.


FYI
3.0 liter 140 hp.
2.5 liter 120 hp
 
Ok thanks. Heading to the lake next weekend and will check it out and try to find local mechanic and not the marina who worked on it last time. We were just curious for answers before we find mechanic.
 
Jeepersji said:
Ok thanks. Heading to the lake next weekend and will check it out and try to find local mechanic and not the marina who worked on it last time. We were just curious for answers before we find mechanic.
Click to expand...

Some advice. When you find a mechanic, don't suggest anything to him. Let him diagnose your boat and see what he has to say first.
 
run -on can be caused by:
poor fuel
high rpm idle setting
advanced timing
high engine temp
carbon deposits on piston

Most times after a hard run you should turn on the bilge blower and let the motor idle a bit to get rid of the hot water in the engine.
 
Chief just turned on a light bulb for me. What year is the boat? Do you have "Turn Key Start" written on top of the flame arrestor??
 
Last edited:
Back
Top