Where's it go?... big plug

[Tanner]

Ok, I've never dewinterized my boat myself. The dealer temporarily winterized it while they had it. When I got the boat back from the dealer, I LUCKILY looked in my glove box to find my plugs laying in there in a baggy. I know where the exhaust manifold plugs go, and the block plug goes. But where does the big round silver circular plug go? Anybody? Pics would be ever so helpful... but I can follow a good description.

[dogbert]

What engine?

[Tanner]

06' 340 MP

Is this a knock sensor? I didn't crawl into the motor to see if I could find where it goes. Trying to save some time, as I'm running this boat to my buddy's stereo shop at 7am.

[dogbert]

I'd check around your water pump.

[chpthril]

My 06 340 has 1 plug in each exhaust manifold, 1 pipe-thread plug in the port side of block, and a knock sensor for the starboard block plug. Same threads and hole size though. Look for a single wire plug laying loose by the starboard motor mount.

http://i181.photobucket.com/albums/x101/chpthril/IMG_5822.jpg

[Tanner]

Thing is about the the size of a Half Dollar, maybe slightly larger. Threaded. and IF I remember right... it has a square head in the center of it.

[dogbert]

Hmm, sounds more like a freeze plug. I'd call the dealer.

[Tanner]

Looks like it might be the engine drain there in chpthril's pic, where the knock sensor plugs into. Hard to tell only going off of the brief 5 secs I looked at it.

[Tanner]

Thanks guys!

[balair]

umm...I'm pretty sure that is the drain plug for the back of the boat....the only square head plug is for the drain plug i think. just look behind you're boat just above your taps plate

[jleger98]

Looks like it might be the engine drain there in chpthril's pic, where the knock sensor plugs into. Hard to tell only going off of the brief 5 secs I looked at it.

I don't have the 340, but my engine has one of these on each side in the exhaust manifold. Threaded and a square hole in it just the right size for a socket wrench.

The other option is to put it in the water and start it and see where water comes out :)

[Tanner]

umm...I'm pretty sure that is the drain plug for the back of the boat....the only square head plug is for the drain plug i think. just look behind you're boat just above your taps plate

LOL... .good one. It's not the drain plug. I can honestly say that after 15 years of boating, I do know what a drain plug looks like. :D

[balair]

ok i was worried there haha...i have never seen a square head on anything else tho..i have the same engine too

[Tanner]

It might not of been square... I honestly can't remember and I'm locked out of my storage after 10. I'm about 95% sure that it's the Engine drain as labeled on Chp's pic. The "square part" I saw, is probably where the wire attaches for the knock sensor. My memory is probably fried... it's probably not even square at all....lol. We'll know tomorrow morn.

Part of the reason I'm so sure is I've never known where the starboard size plug was. Only the port side and exhaust manifolds.

[dogbert]

Yeah, seems like Mercruiser likes to put a bunch of stuff around the knock sensor so you can rip up your knuckles in the process of removing the drain plug.

[Tanner]

O was that a Merc? Thought that was a pic of a Marine Power like mine?

[chpthril]

O was that a Merc? Thought that was a pic of a Marine Power like mine?

We both have the same MP 340. Someone correct me if I'm wrong, but the Merc was the 335 and dont remember if it was offered in 06 or if 05 was the last year.

[dogbert]

Merc was a 315 or 330. Not sure when they stopped offering it, but 05/06 sounds about right.

[illiniboarder88]

Sounds like the engine drain/knock censor. Is there a place on it where an electrical plug can hook to it? Dealers not getting boats water ready apparently is not unheard of. I just talked to a guy out at my lake who had a brand new 08 (not a tige), and he said he realized that as he pulled away from the ramp he realized his boat was taking on water. The dealer had never water prep'd the boat, and a couple of the engine plugs were left out. That just seems plain ridiculous to me.

[dogbert]

Sounds like the engine drain/knock censor. Is there a place on it where an electrical plug can hook to it? Dealers not getting boats water ready apparently is not unheard of. I just talked to a guy out at my lake who had a brand new 08 (not a tige), and he said he realized that as he pulled away from the ramp he realized his boat was taking on water. The dealer had never water prep'd the boat, and a couple of the engine plugs were left out. That just seems plain ridiculous to me.

That's where I think my dealer does it right. The first trip out is always with them. It helps them identify things that need to be fixed and gives them an opportunity to review the features of the boat with their customers. :ro:

When I bought my first new boat, the sales guy did this and it was really helpful.

[balair]

Here's what you do, go to the ramp and back your boat in the water. Start it while it is still on the trailer and look for the leak.. judging by the size of your plug it should be easy to spot.


disclaimer...in no way am i being serious.

[illiniboarder88]

actually, Balair has a potentially good idea (if you don't want to just call your dealer), although I wouldn't go to the ramp. You could probably hook it up to a fake a lake.

[dogbert]

actually, Balair has a potentially good idea (if you don't want to just call your dealer), although I wouldn't go to the ramp. You could probably hook it up to a fake a lake.

Yeah, don't be the guy who ties up the whole boat ramp while working on his boat as scores of other boaters watch in agony. :eek:

[scoot18]

I've got your answer. The plug you have is a riser plug. Look on the back side of the risers and manifolds, probably closest to the back of the boat and wala, there will be your plug. I am using a pic I put in another thread for heater hose location. I added another text box to show your plug location.

[Tanner]

So it was the block plug with the knock sensor as Chp said