Sailpro 6 took a swim...

Hi folks, first time here.

a friends sailpro 6h fell off her transom mount a couple days ago. It wasn't running at the time. I took it home to get it going again. Now I'm getting nothing but a very occasional backfire.

What I've done:

inspected motor housing when I got to the boat -within an hour of submerging. No evidence of water inside the cover anywhere. Easy pull on the starter had no excessive resistance.

Took it home to work on it and did/found the following:
changed oil twice ( it was milky)
replaced plug,
checked fuel pump -working
inspected carburetor -working and clean. Float works, jet unobstructed, no evidence of water.
verified spark with plug out of block, sparking as expected, but can it be insufficient?
checked by hand draw through carb, and suction/compression in cylinder at plug port.
Only took lifter cover off,

all seems to be OK otherwise, but am wondering about timing, or other things to check

suggestions appreciated.

Jeff

Timing is controlled by the CD, so no adjustment. Check ohm values of all electrical components and verify carb has been cleaned, even though it looks OK.

Thanks, I'll recheck / clean the carb tonight. I only found a simple wiring diagram, with no expected voltages resistance values, or other specs. However, I did verify continuity on all connectors, including the oil lamp, the kill switch, and the rectified aux DC output. only have a handheld dvm so couldn't verify the spark wire other than seeing a transient, and seeing the spark.

Can you tell me what I should expect for resistance on the spark cable? Again, I saw no evidence of water in the motor housing itself, especially on any of the electronic components.

J

To test the electrical components, you will want a good analog, not digital, multimeter. I you want to see the pulse going into the CD on a 6A2, your meter needs DVA capability. Tohatsu test procedures use resistance values, rather than voltages for the exciters and pulsers for the MFS6A2 and early 6B, but on the 6C, there is only the igniter, so either it works or not. You did not mention model, but if it's a sail pro, it's likely a 6C. DC resistance across the plug wire to ground should be almost infinite. You can use an inductive timing light to see whether the spark is firing in time with the timing mark on the flywheel. The oil LED should flicker as you crank, showing the low voltage is being generated.

Most issues with the 6C can be traced to fuel. The carb must be impeccably clean. Also verify that the oil is not overfilled... 1/2 way (between the hash marks) on the stick is about right.

Make sure that a good amount of clean fuel is making it to the carb by opening the drain screw. If only a few drops, the carb isn't full. Likewise, if the drops bead up on the block as they drip, they are water -- not gas. Gas should stick to the block as it drips out. Popping through the carb indicates insufficient fuel.

Since there was definitely water in the oil, it's guaranteed that everything was quite wet.

The Factory service manual has full info:
Covers 4hp, 5hp & 6hp "B" and "C" 4-stroke models
Part #: 003-21034-2
List Price (MSRP): $41.67