engine compression and wet spark plug

[Krzysiek]

Compression on one cylinder almost 200 (others between 175-180). Another cylinder spark plug and coil wet on outside. We dried spark plug and coil, put it back run the engine and it was wet again (did it 3 times). No water inside of engine or part of spark plug that is inside of engine. What could be the problem?

 

[rkluck]

When you say "wet" do you mean gas or water? Also, I assume this cylinder is not firing and all the others are? The spark plug that is in the non-firing cylinder should be "wet" from gas on the inside. Can you explain more around the problem you are having?

 

[Krzysiek]

It is water, not gas. All cylinders are working. Water is on spark plug (outside of engine). There is no water inside engine. Spark plug inside engine is dry and ok. this is second cylinder with compression of 180, next cylinder has compression of almost 200. Those are 2 middle cylinders. Thanks

 

[jcyamaharider]

What is your location? Maybe someone in the area could swing by and see what your are working with?

 

[Krzysiek]

NY. This is the boat I want to buy... or not! 2007 sx230 ho

 

[Noko]

Blown head gasket maybe?

 

[Krzysiek]

Noko, that's what one mechanic said. Blown head gasket. But he is not a jet boat mechanic. He said do not a buy jet boat. I called another mechanic, he said do not a buy jet boat.....!!!!!

 

[Gym]

Could be a head gasket. That would come off the asking price. As far as "don't buy a jet boat" that is old, uneducated wisdome. Many of the big boat builders are coming out with a jet propelled offering in their lineups.

 

[Krzysiek]

I want a yamaha jet boat. That one or not. I will get jet boat. Period!!!!

 

[robert843]

I want a yamaha jet boat. That one or not. I will get jet boat. Period!!!!

Get what you want! Most people still have negative thoughts about jet boats but they are thinking old school. By that train of thought don't buy a jet ski either. I took my two jet skis to the bahamas this year and never once was I worried about mechanical failure. I currently own a prop boat, jet boat, and two skis they all serve their purpose and as of now have no intent of getting rid of any of them. All that being said I would probably avoid the boat giving you different compression readings in each cylinder. I'm not a mechanic by any means but I don't think that's a good sign. I'm not sure what your budget is but if you hold out as it gets colder you will find someone wanting to unload a boat at a steal.

 

[Ramblin Wreck]

@robert843 so it sounds like you picked up a jet boat? What did you end up getting?

 

[buckbuck]

There is a gasket between the valve cover and the wells for the spark plugs and cylinder head. Seems to me it would not be too hard to repair. But if it is leaking there it may also be putting water in the oil. Just do the due diligence thing.

 

[rkluck]

I am not a mechanic but I have worked on engines since I was 14. A small difference in compression between cylinders is not that uncommon. The water could be from a head gasket leaking around a water cooling hole and may indicate a slightly warped head as well. Generally this would be due to over heating. Unless you get a deal to make it worth while to take the head off I would pass.

 

[buckbuck]

I remember impelled having a water leak on top of the valve cover. I believe it was a gasket for the cooling water pipe on top near plug 3.

 

[Cobra Jet Steering LLC]

look at the engine while it runs and see where it is leaking, on the outside is probably NOT a big deal , could be the pisser tube or some other hose etc.
clip the rear hatch kill switches to allow the engine to run with the cover open.

 

[Krzysiek]

how much is to change head gasket?

 

[Cobra Jet Steering LLC]

I do not believe that a head gasket is blown, usually the plugs foul and water gets in the oil. been there own the T shirt. I think it is just a small external leak . go to the dealer that services the boat bring the hull ID number and ask for a copy of the service records they may tell you all the info you need.

 

[Krzysiek]

seller of the boat is the dealer!!! they want to sell the boat. It is unclear to me.

 

[Cobra Jet Steering LLC]

Logic would dictate that if it were a simple problem the dealer would fix it and get a lot more for the boat , I think I would try to track down the previous owner or just run away from this.

 

[Cobra Jet Steering LLC]

Based on your post on the other web page I think you had a few more responses here than on the dark side.
http://yamahajetboaters.com/forum/viewtopic.php?f=1&t=67050
Ok on the serious note.
I would be concerned because a boat can be a great thing. Or a huge nightmare. It can make your day or ruin it in a split second.
Is this dealer a Yamaha jet boat dealer? If not he probably knows nothing about jet boats and possibly thinks they are not real boats.
There are a lot of people who think that way, this could be a good thing if he wants nothing to do with it.
On the other hand if he is a Yamaha jet boat dealer he probably knows what the problem is and wants nothing to do with it.
I have boated since I was about 13 years old. So with 50 years of experience and thinking of all the bad things that can happen with a boat if you do not know a great deal about them, You may want to keep in mind that there is nothing better that a good reliable boat that will give you good service and keep your family safe when things get rough or a storm rolls in on you. There is an old saying that lessons are expensive so be keep that in mind.