Sportster Oil Pressure Switch

[ejrice]

Hello, 

I have a 1998 Malibu Sportster with a Carbureted Indmar that has been acting up lately.  The first time we had been skiing on and off for about an hour when the motor sputtered and died.  Upon quick inspection I realized there was no fuel in the carb and the pump was not running with the key in cranking position. This led me to suspect a faulty oil pressure switch.  Luckily we had some wire on the boat to build a jumper to get it fired back up and back to the lift.  The oil pressure gauge is showing normal pressure when cranking and running.  I know these motors tend to have lower oil pressure at idle by nature.  The oil is changed every season and does not appear to burn or leak. A quick trip to the auto parts store and I was able to get a replacement switch, 2 pin only as I had to order in the correct 3 pin, and get back on the water.  I made a connector to tie in the starter wire to give power to the pump when cranking and that worked until I was able to get the 3 pin switch ordered.  After the 3 pin arrived I swapped out the 2 pin and wired back to the original configuration.  The boat had run flawlessly for about a month when the same issue occurred yesterday.  

The boat was running fine for about 15 minutes when it cutout running across the lake about 25 mph.  It would start and run for about 100 yards and die again the whole time showing good oil pressure on the gauge.  The pump was getting power while cranking like it should, but was cutting out after it started.  I have seen on here that the 3 pin switches can be troublesome and that some have switched to the 2 pin with the wire splice to the starter like I did previously.  Is there a reason why the 3 pin would have failed already? I don't want to throw another switch at it, only $6.99 thankfully, in hopes that it gets better so are there any other things I could check first?

Thank you!

[Rednucleus]

Might be a failing fuel pump.  Our 98 Sporty did the exact thing and pump change fixed it.  You could try your switch bypass trick again for a longer time period to see if the problem recurs; just keep a good eye on your oil pressure reading. 

[ejrice]

Hooked up the two prong switch and connected the orange starter wore and red fuel pump wire together.  The boat fired right up and seems to be running fine.  Tested the 3 prong switch and it failed, could not get continuity between the red and purple wires at any oil pressure.  For kicks I plumbed in another external pressure gauge and it matched the gauge on the dash within 2 psi.  Will keep it hooked up this way and test out this weekend.  Thanks for the reply.  The fuel pump is about 6 years old. Is there any test I could do on the fuel pump to see if it's going bad?  It does not get hot or sound bad when it's pumping.  When it was going out before it kept popping the circuit breaker, but had not done this since being replaced. 

Thank you

Edited August 12, 2017 by ejrice

[mcgreg]

Had same issue you describe, traced it to faulty lanyard safety switch. It is a simple on/off switch and you can test it with a continuity light, and/or bypass it by connecting the wires together. You will find the purple ignition wire originates at the lanyard and the purple/ black wire comes from ig switch. 

Good luck!