I recently bought a 2005 GTI. The first couple of times i took it out she ran fine. Third time I ran her for most of the day and then as I was making my way back to the dock, running full throttle, I lost power and she made about 10-15 mph, wide open. Eventually she started running normally again. When I got her home I checked my fuel filter, it was clean, I pulled the spark plugs and the forward plug had zero gap. I put in two new plugs and took her out again, this time she only ran for about 45 minutes and I had the same problem only she would only make a 2-5 mph. My buddy that I was riding with talked me into stopping and looking under the seat to make sure the throttle cable was working properly, it was but then I wasn't able to get the ski started again so we towed her back to the dock. This time, the aft spark plug had no gap. Once again I put in new plugs, took her out the next day and again she ran great, rode her all day and then when we were 10-15 minutes from the dock, she bogged down, made 10-15 mphs back to the dock, rode her up onto the trailer. When I pulled the plugs this time, again it was the forward spark plug with no gap. Anyone ever encounter something like this? Any suggestions?
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Conundrum
- Thread starter abadaba
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Using NGK BR8ES plugs, while searching online I came across a site that states they are supposed to be BR8ES-11 plugs. I found some on amazon and have ordered 2 of them. Not sure what if any difference in these compared to what I bought this morning at O'reilly's (BR8ES)but since Im replacing a plug every time I take ihe ski out, I don't suppose it could hurt. With a flashlight, I am able to look down into the forward cylinder, I can see the piston but I dont see any sign that its been hitting the spark plug.
So Ive been told that I may have water in my fuel, when it gets in the cylinder at ignition it has no where to go and for some reason is pushing up on the side electrode seeking a way out? Sounds semi plausible and as I have a crack in the side of my gas cap, Im thinking maybe there is something to this. The gas cap has a rubber seal that I would think would keep water that might get in from the crack out but who knows?
No, water will not cause the plug electrode gap to close.
Running at WOT then it slows down to 15 mph tells me you were running lean and seized the engine. That and having the spark plug electrode collapsed tells me you had something mechanical let go inside the engine.
Your next step is to check compression.
Running at WOT then it slows down to 15 mph tells me you were running lean and seized the engine. That and having the spark plug electrode collapsed tells me you had something mechanical let go inside the engine.
Your next step is to check compression.
I guess Im not quite as mechanically adept as most of ya'll but how could you even do a compression check if something in my engine has seized? Correct me if Im wrong but if I had a seized piston, how would the crankshaft turn to supply compression to anything? If something in my engine was seized, how would the jet ski even start to do a compression test?
In your first post you said you were running wide open then it just went to 15mph. Typically on these when that happens it is because it was starving from fuel and went lean. This causes the lean cylinder to seize. It will in many cases restart and turn over but the damage is already done.
A compression test would help verify this without pulling the head or anything and is why I suggested it.
Now with the picture of that plug it does look lean and silver so you could very well have detonation and that is aluminum from the piston on the plug.
Is this a 720 GTI or a 787RFI?
At this point you just need to pull the head and see what damage has been done.
A compression test would help verify this without pulling the head or anything and is why I suggested it.
Now with the picture of that plug it does look lean and silver so you could very well have detonation and that is aluminum from the piston on the plug.
Is this a 720 GTI or a 787RFI?
At this point you just need to pull the head and see what damage has been done.
Well, when a cylinder runs lean it gets hot. This vaporizes the thin film of oil between the cylinder wall and piston then you have metal on metal contact, thus a seize. Just because it turns over and runs doesn't mean you're pistons aren't scuffed up.
I am not saying that is what happened to yours but spark plug electrodes don't just bend over like yours did.
I have never seen one do that and it isn't normal.
As Chester suggested you could be getting detonation also.
You really need to just pull the head. It shouldn't take more than 10 minutes and uses o-rings to seal not a gasket.
That ski has a single carb and your other plug looks good. You need to find out what is going on in the cylinder with the bad plug.
I am not saying that is what happened to yours but spark plug electrodes don't just bend over like yours did.
I have never seen one do that and it isn't normal.
As Chester suggested you could be getting detonation also.
You really need to just pull the head. It shouldn't take more than 10 minutes and uses o-rings to seal not a gasket.
That ski has a single carb and your other plug looks good. You need to find out what is going on in the cylinder with the bad plug.
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Most of the time when these things seize, it's only for a brief time. By the time you float to a stop, it will usually cool off enough to let go and start right up again. No need to do a compression test. See those little gray specs on that bent plug? That's from your melted piston. Pull the head off, the damage is done.
Chester
Chester
so Ive pulled the head cylinder, if you look closely at the 2nd picture you can see some water to the side of the cylinders. As i was carefully removing the head, I didn't see a hose that was connected down to the manifold, down underneath it, it jerked the head out of my hand and spilled water down in the lower end, what can I or should I do to prevent any further damage down in there?
WOW!
That engine is done.
My guess is dirty fuel system and old gas. That thing needs the cylinders bored and new pistons and 99% sure it is going to need a crank too.
You are going to have to do a full tear down and inspect the rotary drive too.
If you are not the mechanical type then just send it for an exchange to SBT and be running again in a couple weeks.
Also what oil were you using? I can see what looks like a black oil supply hose in the picture.
That engine is done.
My guess is dirty fuel system and old gas. That thing needs the cylinders bored and new pistons and 99% sure it is going to need a crank too.
You are going to have to do a full tear down and inspect the rotary drive too.
If you are not the mechanical type then just send it for an exchange to SBT and be running again in a couple weeks.
Also what oil were you using? I can see what looks like a black oil supply hose in the picture.
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