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wats218
12-29-2012, 09:31 AM
Winterized the boat about a month ago. Drained the exhaust manifolds and port side block plug, pulled the thermostat, and then ran 5 gallons of rv antifreeze out of a bucket through the entire engine. There was definitelt]y red antifreeze coming out of the exhaust.

I've been doing some reading on this site and it seems that everybody removes the drain plug on the starboard side of the block as well. Since I use the cheap rv antifreeze, I figured I'd do the same just in case the antifreeze was diluted too much. On my engine, this drain plug has the knock sensor on it. I got a 7/8" wrench and started turning the knock sensor to remove it. My problem is that the center hex head spins, but the outside housing and the threads in to the block do not. Is there a trick to removing the knock sensor? Did I damage it? The center hex does not spin smoothly, more in rough steps. Below is a link to skidim for the knock sensor that I have.


http://www.skidim.com/prodinfo.asp?number=R020027

ProStar Slalom
12-29-2012, 10:11 AM
I've got the same sensor and just loosen with a wrench as you describe; never had just part of it turn, so it sounds like something isn't right. I'm sure a better wrench will jump in here shortly.

mikeg205
12-29-2012, 12:28 PM
sounds like time for a new knock sensor. appears outer housing loose from over torquing when installing over there years. It only has to be snug.

MLA
12-29-2012, 12:36 PM
Loosen is up with a pair fo slip-joint plyers on the outer body. I would then suggest replacing it.

jakethebt
12-29-2012, 12:46 PM
What he said^^^^^^

EricB
12-29-2012, 01:07 PM
I 3rd what MLA suggests.

wats218
12-29-2012, 02:34 PM
Thanks guys. I just wanted to make sure before I took pliers or vice grips to the outer housing.

Jerseydave
12-29-2012, 04:55 PM
Loosen is up with a pair fo slip-joint plyers on the outer body. I would then suggest replacing it.

ditto, the outer housing is peened over to the inner part. Small pipe wrench on the outside should take it out, then replace. I take mine out every year to winterize.

mikeg205
12-29-2012, 10:11 PM
ditto, the outer housing is peened over to the inner part. Small pipe wrench on the outside should take it out, then replace. I take mine out every year to winterize.

Hey I learned a new word today... :) and the wives laugh our boating addictions.. ;)

94PS190
01-02-2013, 05:12 PM
I don't know what slip joit plyers are, but I would use dogs, or channel dogs to be more specific,

JimN
01-02-2013, 07:57 PM
Winterized the boat about a month ago. Drained the exhaust manifolds and port side block plug, pulled the thermostat, and then ran 5 gallons of rv antifreeze out of a bucket through the entire engine. There was definitelt]y red antifreeze coming out of the exhaust.

I've been doing some reading on this site and it seems that everybody removes the drain plug on the starboard side of the block as well. Since I use the cheap rv antifreeze, I figured I'd do the same just in case the antifreeze was diluted too much. On my engine, this drain plug has the knock sensor on it. I got a 7/8" wrench and started turning the knock sensor to remove it. My problem is that the center hex head spins, but the outside housing and the threads in to the block do not. Is there a trick to removing the knock sensor? Did I damage it? The center hex does not spin smoothly, more in rough steps. Below is a link to skidim for the knock sensor that I have.

http://www.skidim.com/prodinfo.asp?number=R020027


The knock sensor was probably over-tightened previously- it's supposed to go finger-tight and then go 3/4 turn tighter. The suggestion to use Channel-Locks (slip-joint pliers) is a good one, especially since it will be replaced, anyway.