Helluva SXR issue...need analysis

[Jetaddict]

This may be long, but both myself and Tom21 need some input:
2005 SXR- recently (and suddenly) started running bad: take it out on the water, it'd run decent for about 10 minutes, then it would begin to sputter- at full throttle the power would drop off every 2 or 3 seconds or so. After a few more minutes, problem gets worse, until finally the ski runs as if it is on one cylinder, won't go over 2 mph, and there is only one spot on the throttle where it will run at a fairly good clip. If you move the throttle a millimeter in any direction, it will bog.
Take it out of the water, it revs fine, or so it seems. Even after sitting in the water for an hour, you take the ski out again and it IMMEDIATELY runs like crap.
Then, upon pulling the plugs, it appears as if the ski is ingesting water. Clean up the plugs, ski starts up fine.
Exhaust seems unusually hot (both water coming out of the pisser and the pipe itself-STOCK exhaust).
Pulled the head and pipe- no evidence of leaks or failed gaskets.
Bring the ski home, let it sit in garage for 2 days. Go to fire the ski up, it won't start. Pull the plugs again, and notice water condensation on the electrodes and porcelain. Dry off plugs, spray with WD, ski fires up. Pull plugs again, notice similar water condensation on plugs...very odd.
Thinking bad fuel, water in tank, plugged up carbs, or even an electrical issue. Ski is totally stock. Had an ignition advance jumper, but when replaced the jump with the stock temp sensor, ski ran the same way- crappy.
I tried to make this short- anyone EVER experienced this and have ANY clue what is up? I cannot understand how the ski can sit for 2 days, and water is present in the cylinders and ends up on the plugs. Ski has not been submerged or ingested water badly for months.
THinking of checking the carbs for water, maybe doing a rebuild (it's a 2005 ski, never had a rebuild) , and then draining the tank and checking for water. I've ran about 1/2 a tank of gas through it and it doesn't seem to be getting any better....HELP!!!

 

[Shonuff]

You may have a crack in your top end allowing water into the case from your normal cooling route. I can't really think of any other way.

However, if Tom21 is even remotely stumped, then I'm surely no help as he is the man.

 

[Shonuff]

My scenario makes sense to me in that eventually the water intrusion would interfere with normal combustion and foul a plug. A small crack would take time to build up enough water to do so (the ten minutes of "running decent")

I could be wrong but I would at least look there. I think it would still pass a leakdown since the crack would be internal.

 

[Crab]

Pressure test should reveal a crack, water jackets don't normally have pressure when testing, just the cases, intake, exhaust, and cylinders.

 

[tom21]

I pulled the head and the exhaust, it doesn't have any pits or cracks on the sealing surfaces, or in the pipe. you would see a clean spot.

he also did not mention that the ski ran fine on a few occasions for what 5 minutes and then acted up. found the plug ends not making a great connection and it turned out to be it only ran for a few minutes before going to crap.

also he has revved the ski after riding it and not seen any more water out the exhaust and then found water on the plugs days later????

1- I am not convinced the coil wires are all the problem but I am not convinced they are not some of it. when I rode it I would describe it as the spark cutting on and off on one cylinder. idles fine. one plug was not real dark like the other. now with the water on the plugs we figured it was not a spark issue but a water intrusion issue.

it also became very water ingested just sitting on the beach in a few inches of water.

2- water is getting into both cylinders after running the ski in fresh water, and then clearing the exhaust. HOW??? I am game for draining the tank, or inspecting the carbs for water which is easier for me. have not so far cause the ski was running fine at first and then messing up when warmed up, didn't have the wet plugs yet.

poor jetaddict is losing his mind, give us some more ideas on where to look, I have been trying to go real easy on his wallet- so far he is down a 12 pack.

jetaddict - please feel free to correct me or add to this. I figured more info is better???? we'll get it.

 

[Scorn800]

Sounds like water in the fuel to me. I'd remove the fuel picks up from the tank and siphon all the fuel out and check for water. Then dive into the carbs.

 

[tom21]

anyway to explain how the ski got completely water ingested while sitting in the water? I guess taking it one step at a time would be best, this is what is frustrating so many weird things goin on all at once.

 

[ger87410]

Too bad there wasn't a way to keep the engine cool without water.....

Have you checked your coil (or do these have CDIs?), stator, and spark plug wires?

Maybe the water is coming back in from the exhaust?

Every time that you've tested this ski, it's been in the lake?
Can you do the same test with the ski on the hose? I may be wrong, but the water pressure on the hose could be less the the water pressure from the pump when in the water. :shrug: That'd atleast tell you if it's a pressure thing.

What's your compression?

 

[tom21]

Too bad there wasn't a way to keep the engine cool without water.....

Have you checked your coil (or do these have CDIs?), stator, and spark plug wires? sure maybe there is a problem there but the immediate concern is why water is in the motor.

Maybe the water is coming back in from the exhaust?should only get into the motor if it was above the exhaust opening for a good bit and since the ski was higher in the water then when it is floating I don't see how this would happen

Every time that you've tested this ski, it's been in the lake?
Can you do the same test with the ski on the hose? I may be wrong, but the water pressure on the hose could be less the the water pressure from the pump when in the water. :shrug: That'd atleast tell you if it's a pressure thing.not sure this would help as water still gets in somehow when the ski is revved without water and ends up with it in the motor. which as scorn pointed out could be water in the fuel but doesn't explain a completely ingested motor while resting in the water.

What's your compression?

according to my gauge its 150

 

[SuperJETT]

What is the exhaust setup? My old 550 mod had right-front side exhaust with Westcoast pipe/Jetcraft Turbomuff/total loss, and every once in a while when I shut it off, if the exhaust were completely underwater and the pistons were at the right place when I hit stop, it would completely flood the exhaust with water to the point of water getting back in the cylinders. Happened probably once a month when I was riding it a lot back in the day. The first 'high point' the water was was the headpipe.

This is a hard one.

 

[Jetaddict]

I am thinking that there is something up with the exhaust system too-here is why I am arriving at this conclusion:
I know that when you tow a ski above idle speed, and the ski isn't running, they tell you it's a good idea to block off the water lines so water doesn't "backflow" into the motor and swamp the motor, right? Is there a way this can occur under normal conditions, or when the ski is just sitting? The plugs on one occasion showed classic signs of water ingestion-wet, grey deposits all over them- a mixture of oil, water and gas...yet, the ski had NO water in the hull and it was not splashing in the carbs (I have a stock pipe and use the stock waterbox and flame arrestor). It was just sitting in the water near the beach like it always does.
Additionally, when I had the hood off at Tom's shop one day, he pointed out an RPM associated "ticking" noise that sounded as if it was coming from the lower manifold area of the exhaust. This noise is hard to pinpoint and is transient, and as he said, he pulled the exhaust and all looked fine.
I mean, is it possible for water to be backflowing through the exhaust while the ski is stationary and cause the ingestion?
As for the running issue, I would also lean to 1) ignition system or 2) water in the tank. I wish I had fuel filters so I could see any obvious water in there instead of yanking the whole tank, but oh well. It almost seems as if there are two separate issues as opposed to one major one...or so I hope.
Tom, I would think we start with the fuel and check for water- either by yanking the tank or opening the carbs...maybe check to see if a rebuild is necessary. Then, maybe check the ignition system- and see if maybe the coil or something else is flaky. Lastly, check the entire exhaust/intake system for leaks or some way this water is backflowing into the system- I have no clue how the whole setup is routed or how it truly operates, maybe there is a check valve or something that is bad, or something similar? I actually miss working on the Yamaha 701- it seemed to be a lot simpler to figure out issues with that motor and it was usually something glaringly obvious.
Thanks for the input so far, guys.

 

[tom21]

I'm game, and this will probably be glaringly obvious once we figure it out.:rant::banghead:

the exhaust is built like plumbing, it would have to rise over the top of exhaust port roughly to get thru the exhaust into the motor. unless there is a leak somewhere. which if there was you should see a clean spot around the crack.

just was hoping someone had similar issues or had some more ideas on what else we may not be thinking of so we can cover more ground when we tear it up.

usually its a case of thinking too hard and overlooking the easy obvious things.

 

[Jetaddict]

Tom, I am out of town this weekend, so I'll probably bring the beast by next week sometime. In the meantime, maybe someone else can offer up some advice...

 

[Jetaddict]

Oh...a buddy of mine sent this to me...he knows a lot about cars and engines, but it sounded like it makes some sense to me:
"Honestly, it really sounds like water in the tank, carbs, or both. Unscrew your float bowls (I assume this is a normal carb setup) and check for water beads. What I am guessing, and this is only a guess, is that somewhere along the line you got water in your tank. As the ski runs, the water beads get smaller (imagine shaking up oily salad dressing)and get into the fuel lines, and therefore the float bowls. The same vibrations happen in the bowls, and then it gets into the motor. This also explains why it runs fine at first, because the water is beaded up really big at first, and isn't going anywhere. I assume that since it runs fine at a certain rpm, that is a harmonic resonance that is agreeable to the ski, and is keeping the water bubbles from geting into the motor.

Again, strictly a guess, but worth a shot."

Makes sense to me except the bowls.

 

[ger87410]

Makes sense to me except the bowls.

That and it's not happened once or twice but keeps happening.

 

[WFO Speedracer]

That and it's not happened once or twice but keeps happening.

Ok a couple of things here,I would say its a stator issue but you are talking water intrusion so here goes.I was working at the Kawi shop and we sold a new X2,the customer immediately brought it back and said it didn't run right.I did the usual checks,compression was good,pulled the carb,nothing there,full electrical diagnostic,nothing there,replaced the head gasket same deal.I went to water test it,as soon as you put in the water one cylinder died,pull it out and it ran on both.So back into the engine I go,nothing obvious wrong ,no visible damage anywhere.Here is what I did,I filled the shop sink full of water,I left the head on and unbolted the cylinder from the block,I made a hose up to pressurize the cooling system and with the system pressurized dunked the cylinder,Immediately air bubbles start going everywhere,upon further inspection I find a small hole in the casting going from the cooling passages directly into a transfer port on the cylinder that was dying.We ordered him a new cylinder and put it on and never saw him again the end.

 

[Crab]

Ok a couple of things here,I would say its a stator issue but you are talking water intrusion so here goes.I was working at the Kawi shop and we sold a new X2,the customer immediately brought it back and said it didn't run right.I did the usual checks,compression was good,pulled the carb,nothing there,full electrical diagnostic,nothing there,replaced the head gasket same deal.I went to water test it,as soon as you put in the water one cylinder died,pull it out and it ran on both.So back into the engine I go,nothing obvious wrong ,no visible damage anywhere.Here is what I did,I filled the shop sink full of water,I left the head on and unbolted the cylinder from the block,I made a hose up to pressurize the cooling system and with the system pressurized dunked the cylinder,Immediately air bubbles start going everywhere,upon further inspection I find a small hole in the casting going from the cooling passages directly into a transfer port on the cylinder that was dying.We ordered him a new cylinder and put it on and never saw him again the end.

PRESSURE TEST!

 

[WFO Speedracer]

PRESSURE TEST!

This show up during a pressure test of the crank seals but,the pressure test of the seals would have never revealed the true cause of the leak!:bigeyes:

 

[Shonuff]

Ok a couple of things here,I would say its a stator issue but you are talking water intrusion so here goes.I was working at the Kawi shop and we sold a new X2,the customer immediately brought it back and said it didn't run right.I did the usual checks,compression was good,pulled the carb,nothing there,full electrical diagnostic,nothing there,replaced the head gasket same deal.I went to water test it,as soon as you put in the water one cylinder died,pull it out and it ran on both.So back into the engine I go,nothing obvious wrong ,no visible damage anywhere.Here is what I did,I filled the shop sink full of water,I left the head on and unbolted the cylinder from the block,I made a hose up to pressurize the cooling system and with the system pressurized dunked the cylinder,Immediately air bubbles start going everywhere,upon further inspection I find a small hole in the casting going from the cooling passages directly into a transfer port on the cylinder that was dying.We ordered him a new cylinder and put it on and never saw him again the end.

Wedo, can I fill out an application to work for you since clearly we great minds think alike?

 

[SJ/XPBri]

This show up during a pressure test of the crank seals but,the pressure test of the seals would have never revealed the true cause of the leak!:bigeyes:

I'd personally do the pressure test, why pull the cylinder, when you have no idea that there is a leak in the first place?
Bri
Edit: I like your second step testing procedure, just don't think he's at that point yet