Hoppy
Jet Boat Junkie
- Messages
- 179
- Reaction score
- 526
- Points
- 142
- Location
- North Platte, Nebraska
- Boat Make
- Yamaha
- Year
- 2003
- Boat Model
- LX
- Boat Length
- 21
So o rebuilt the carbs got it all back together made sure cylinders was getting oil started it a little above idle then receding it up to 3k and then I tried to turn it off and it kept going with the key off at 3k had to put my hands over the intake to shut it down, you know what’s causing this ?
One of two things:
There is a black and a white wire in the harness that should connect together to kill the engine. There are three switches that are capable of killing the engine: the key switch, the lanyard switch, and the clean out hatch switch. If one of the other switches in the circuit will the engine it's a bad switch. If non of the switches will kill it and the black and white wires are not disconnected someplace the it is likely running to lean.
An engine running lean will run hot causing any carbon on the pistons to glow with enough heat to cause combustion without spark from a spark plug. Running lean can be caused from fuel delivery problems/ carburetor adjustments or an air leak in the intake or crankcase. If you can kill it by opening up the throttle and cooling the cylinders off with a flood fo cool air then it is likely running lean.