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Grover777
10-19-2008, 05:50 PM
Me again!

Just removed the drain plug with the knock sensor...its handy to have the laptop in the boat!

There is a bit of black gunk on the end which is in the block. Should I clean this gunk off? It almost looks like carbon.

Thanks for all of the help!!

JimN
10-19-2008, 06:05 PM
Black gunk on he knock sensor? Clean it off, but it won't affect the sensitivity since the sensor is basically a microphone and picks up the vibrations from the block. Make sure the water rushes out of the block from the hole where the knock sensor is mounted. If it doesn't rush out, get a fitting to adapt from a garden hose to screw in or a barb that will connect to a primer bulb and fuel line (this will only be used for water after this point, not fuel). It's probably silt and it definitely needs to be flushed out.

Grover777
10-19-2008, 06:06 PM
Thanks Jim!

The water did rush out of the block and everthing appears ok in the drain hole...

When I go to reinsert the knock sensor, it goes in easy by hand turning about 1/4 of the way then gets very hard to turn. Is this normal? I do not want to risk forcing it in and stripping the threads in the block...

Thanks again!

Jesus_Freak
10-20-2008, 10:23 AM
Thanks Jim!

The water did rush out of the block and everthing appears ok in the drain hole...

When I go to reinsert the knock sensor, it goes in easy by hand turning about 1/4 of the way then gets very hard to turn. Is this normal? I do not want to risk forcing it in and stripping the threads in the block...

Thanks again!

Mine does this also; hope it is normal. :o

JimN
10-20-2008, 10:27 AM
Don't worry about how far it goes in- get it finger tight and add 3/4 of a turn. Its an NPT tapered thread. You won't strip the thread in the block but you can strip the sensor or break it off.

Tapered fitting into straight threaded hole=good tight fit with minimal torque.

Grover777
10-20-2008, 11:48 AM
Thanks Jim! I ran across one of your posts later last night that helped as well!