View Full Version : No fuel to carb?

04-08-2012, 04:58 PM
Put the boat back together and went to go out on the lake. Boat would crank but not start (2002 Mobius LSV Carb). Pulled the cover off the carb and there was no fuel spraying into the carb, even when pumping the throttle. I tried to check the voltage to the pump, but it returned zero.

I am confused about the operation of the pump, does it run when the key is in the on position?

Should it be getting power when the key is in the on position?

Manual shows a fuse location, but I do not see a fuse for the pump?

Normally when I cold start I pump the throttle to get some fuel in the carb, but now I cannot get any fuel out. I am at a loss.

04-08-2012, 10:02 PM
Better check that kill switch. That disables the electric fuel pump. Just happened to me about 3 weeks ago.

Engine Nut
04-08-2012, 11:05 PM
The fuel pump comes on only when the starter is engages and the engine is cranking, or if the engine is running. There is a fuel pump safety switch located by the distribuutor. Depending on the year of your boat, the switch will have three terminals or two. To see if the pump is functioning, you can temporarily hot wire the pump by jumping the purple to the red wire and see if the engine starts. If you have the two terminal switch, just run a temporary jumper from one terminal to the other. If the pump runs and the engine starts with the switch jumpered, you may have a bad switch. If the pump runs but the engine does not start, the pump may be the problem. DO NOT UNDER ANY CIRCUMSTANCES LEAVE THE JUMPER ON EITHER OF THE SWITCHES. YOU WILL BE UNSAFE AND IN VIOLATION OF COAST GUARD REGULATIONS. If the pump runs but will not pump fuel, check the fuel filter. It is also possible that the centrifugal vanes in the pump are stuck. ou can take the top off the pump and clean the vanes with carburetor cleaner.

04-09-2012, 09:04 AM
Thanks, I am gonna try this tonight after work.

I also plan to check the fuel filter and float.

04-09-2012, 09:51 AM
One more question, if I pump on the accelerator pump level on the carb, should this allow fuel to pump through even if the fuel pump isnt working?

I would think, no. Since there is not fuel in the line up to or beyond the pump to kick into the carb. Am I correct in this thinking?

04-09-2012, 07:40 PM
Ok, went through and checked everything, along with spending some time on the phone with the service department at the closest dealer.

Filter can pass through, and with a hand pump I can draw fuel from the tank.

Pump runs but will draw no fuel, looks like the pump has just gone bad.

Ordered a new pump and fuel filter from Skidim, should be here an installed by next week.

04-10-2012, 03:13 AM
It could be the oil pressure switch on the engine.I think if it is bad it shuts down current to the pump.
check out this post,


hope it helps.

04-18-2012, 11:14 AM
New pump from Skidim (first time buying from them, and they are great) and I am back in business. Checked the pump in the driveway by running off a battery to ensure I was getting gas to the carb. Took the boat over to the lake and it fire right up, ran strong, no problems.

The new pump did have different connections that my old, so I had to by some new connectors and re-wire the harness.