Need help - Blistered spark plug wall

[waterdog15]

Hello All,
I have an interesting series of questions. I have a 2005 Seadoo GTX. When my jet ski wouldn't start, I noticed the company who performed the winterization had left the spark plugs disconnected and also the #2 spark plug insert was about an inch from being seated. When it was removed, you could see rounded indentions in the chamber the spark plug goes in (imagine what looks like 3 blisters). If the stamped cylinder identification is 12 o'clock, the blisters are located from noon to 4 o'clock. Although I don't think it is related, the top of the spark plug (the threaded end) is bent. There is no way to get the plug out with the cylinder wall the way it is. The plugs haven't been changed since I owned the ski (the winterizing company was going to do it until they saw the blisters)

I bought the ski used from a local dealer 2-3 years ago. When I test drove the ski, it would go accelerate awesome but would not go above ~35/40. The dealer said it was due to a wear ring needing replacing. They fixed the wear ring and I bought the ski. The ski ran 70+ mph then and as of last year ran 70+ mph.

Any idea as to the cause of the blisters? By the rounded nature, I am guessing possibly the "chamber" behind it was over pressurized?? What is behind this area?

Due to the bent spark plug tip and the "wear ring", I am wondering if I was taken advantaged of. I am thinking it was actually running on 2 cylinders vs. 3 cylinders. What are the signs of this? And what are the signs of a bad wear ring?

Thanks for any help,
~Waterdog

 

[seadooman55]

if you had a bad wear ring it would only run about 10 mph slower. Mine was really bad, like would hardly get on plain but once it got going it still would pull 10 mph slower. If your running almost half the normal speed then your either in learning mode or like you said running on 2 cylinders. I had a bad ecu that shorted 2 of the coils and they were blistered and bent at the top of the plug NOT the bottom sounds to me like the coil pack was just set on top of the plug cause the spark to jump to the plug making it hot and warping the tip like you said that could explain why it ran good sometimes and not so much other times. good luck!

 

[waterdog15]

One thing I don't think I clarified very well is that it is actually the metal wall of the chamber that is "dented" or "blistered" in. In other words, a socket can not get past the blisters to remove the spark plug from the machine. Additionally the tip of the spark plug the rubber boot connects to is bent.

So the sign of a bad wear ring is it is slow to get to speed and a reduced top speed?

Any ideas of what the blisters/dents could be?

Thank-you!

 

[ski-d00]

depends how bad the wear ring is as to how much speed you will lose, have seen them really bad where it won't even get on plane. bad wear rings usually cause high rpms and slow to get up to speed and lower top speed. if your ski was going 70 on the speedo, then it isn't running on 2 cylinders, that's for sure.

I've never seen a spark plug tube damaged. Can you take pics and post? I suspect it is from some moron changing the plugs not knowing what they're doing, like trying to put a plug in when it already had one in and got it stuck. It is not difficult to replace the spark plug pipe, just remove the valve cover and the tubes come right out. I'm sure I have a few extra spark plug tubes lying around, list price on them is $21, I'll sell one for $15 shipped. PM me if interested.

 

[seadooman55]

yea i agree, wear rings wont cut your speed in half because by that point your not even getting on plane. along with the moron part about getting the plugs out there are some real hackers out there.

 

[waterdog15]

Here is a JPEG but don't know how to insert it. In the picture it is hard to tell but look to the right of the cylinder. The "blisters" start about 10 o'clock and continue to around 5 o'clock. The worst is between 1 & 2 o'clock. I think the bent tip came from someone changing the plug but the blisters had to come from inside the engine (isn't this called the top head?).

Can I email the picture?

Thanks,
~Waterdog

 

[waterdog15]

Update on "blisters" in spark plug tube.

The dealer got the ski and tore in to it. I am not a mechanic by any means and it was only 2 minute conversation as they were just starting. Anyway, he said the rocker arm came loose and something about a babbit bearing and needle bearings going through the engine. He said there was metal in the oil. Evidently, this is what caused the dents in the spark plug tube. He was saying it looks like it would need a new engine. I asked about just putting it back together but he said it would need some work (at least a ?piston?). He if we did that, it may last an hour or 5 years..... He also said they also need to check ?the cam?.

Can one of you guys translate and give your opinions - Any ideas how much an engine for a 2005 GTX Limited would be?

Thanks,
~Waterdog

 

[seadooman55]

sounds like just your top end is messed up, if they could just pull the head off and check to make sure nothing else is messed up then i dont see why they can't just replace the head. It would be alot cheaper hower i do agree with them with the metal in the engine part because when bearings go out it can be small filing or bigger hunks you cant tell since it is in a boat you cant pull the oil pan without pulling the motor. I would not risk that since it is an exspensive engine. SBT wants about $1700 for a new engine plus the 80 to 90 an hour shop time to put it in so you are looking at over 2k to repair it if your planning on putting a new engine in it.

 

[waterdog15]

I just heard from the dealer and they said the cam also needs to be replaced. Their estimate to replace the cam and all of the rocker arms is $1600.

Seadooman55, you said you "would not risk that since it is and exspensive engine" - risk what pulling the engine or just fixing the head?

Looking at SBT's website, the engine is ~$2700 for a remanufactured Sea-Doo 4TEC SC Premium Engine and it has a 2 year no-fault warranty. I would have to add labor to that for installation. How many hours labor does it take to install one?

Any thoughts?

 

[seadooman55]

the "risk" i am talking about is the metal shards that might have came off when the bearing blew out. If the dealer is pulling the motor to do the cam and rocker arms, then just have them check everything out, but if there leaving the motor in and doing the work you might have the metal shards in the oil pan and as soon as you run it, they will rip the engine apart. But you dont know what might be floating around in the engine that is the risk. it could be cheaper then replacing the engine if nothing else goes wrong but if they fix that engine and something else goes wrong youll end up paying more then if you where to have just put a new engine in in the first place. The dealer can probably swap the engine in and out 2 hours each way. That is a rough estimate. It was about 2 hours for me to pull a 2 stroke engine so a tech could probably do a 4 stroke engine in about the same time. so the desicion is yours, you could also have them pull that engine and check it over and replace the broken cam and rockers and that might be another alternative route.

 

[waterdog15]

The shop wanted $1600 to do the rocker arms & cam or $3800 to do the engine. I decided to just do the engine and avoid the chance. They told me that it is a Seadoo engine (evidently they have rebuild department) and will have 1 year parts and labor warranty.

I am just glad I have a money tree in the back yard....... at this rate, I may need to plant another one.

thanks for your input,
Waterdog