Burnt tuned pipe and manifold

[kicker]

Picked up a 97 GSX a couple weeks ago. The tuned pipe and exhaust manifold were very hot at one point as you can see in the pics. By the looks of it, the gasket let go where the manifold and pipe join and the water could not cool the pipe properly. Looks like the PO tried to stop the leaks with some form-a-gasket which I am sure did not work very well.

The rubber joiner and rubber pipe going out the stern look fine, But by the looks of the blue gasket around the pipe fitting on the stern it must be leaking there too. The rave pressure valve also got melted

When this happens, Is there any other possible damage that I should look for? Would the engine have over heated because of this as well? Would the manifold get out of shape when it gets this hot?

Also if there are any tips out there on how to repaint the pipes/manifold that would be great.

 

[kicker]

Can anyone tell me if the pipe was originally white is was it purple like my 96 GSX?

 

[Strizzo]

97 787 pipes were white, i thought the factory paint had something in it that would turn it golden brown if it was overheated, but maybe the water running over the outside is what caused that paint to flake like that.

 

[Minnetonka4me]

That fawker got hot thats for sure. That guy liked his blue RTV! I hate using it, but my source (thats free) has every color other than black.

The big question was why it overheated. If it was the water regulator I doubt it would have gotten THAT hot, but the engine would have been cooled.

If something got plugged and the engine overheated like the pipe....its possible that the bearing races melted. You can usually take the spark plugs out and turn it over by hand and hear the balls clacking together.

The exhaust gasket is known to get weathered and leak. Usually it allows the big nut on the back get loose and it vibrates even looser.

Here is the tool you need to make if you want to tackle it....the OEM tool is discontinued. The fun part is taking out the brass fitting before you can use it.






These other guys are better with the paint so ill let them cover that.

 

[Matt Braley]

Um..what are you doing to a 787 with that home made tool? I read it over agan and still missed it. Tackle what?

 

[CReynoldsMIZ]

Um..what are you doing to a 787 with that home made tool? I read it over agan and still missed it. Tackle what?

Im stumped as well....

 

[Strizzo]

i think its for the nut on the exhaust outlet

 

[Matt Braley]

i think its for the nut on the exhaust outlet

I still don't see it. What would be wrong with a 17mm wrench?
Oh I get it. In the through hull out back.

 

[racerxxx]

How's the under side of the seat look? That is one crispy critter right there!

 

[kicker]

racerxx, not sure if you being sarcastic, but the underside of the seat is fine. My guess is that the gasket between the manifold and tuned pipe let go so no water was able to travel through the pipe and manifold. I pulled the plugs, the manifold is off, took the rotary cover off and the rave valves are out.

I did as Minnetonka suggested and jiggled it around and listened for any abnormal noise inside. There is only slight "clicking" when i grab the pto with 2 fingers and jiggle a bit, not enough to feel through the PTO, but I can hear the clicking. It actually feels tighter with less play then my 96 GSX. It definitely doesn't sound like loose balls kicking around.

I will say that the jugs are not as brown as the manifold but not white like the crankcase, not peeling or anything just discoloured. Not sure this is just a normal thing that happens because the pistons will be hotter than the crank.

 

[kicker]

The thru hull pipe is toast as well, Minnetonka what size ID do I need to make that tool? It's to deep in the hull to try and get a measurement.

I hope that's all that got scorched.

 

[DA080682]

Picked up a 97 GSX a couple weeks ago. The tuned pipe and exhaust manifold were very hot at one point as you can see in the pics. By the looks of it, the gasket let go where the manifold and pipe join and the water could not cool the pipe properly. Looks like the PO tried to stop the leaks with some form-a-gasket which I am sure did not work very well.

The rubber joiner and rubber pipe going out the stern look fine, But by the looks of the blue gasket around the pipe fitting on the stern it must be leaking there too. The rave pressure valve also got melted

When this happens, Is there any other possible damage that I should look for? Would the engine have over heated because of this as well? Would the manifold get out of shape when it gets this hot?

Also if there are any tips out there on how to repaint the pipes/manifold that would be great.

Holy COW!!!! Given the water flows across the top of the head then out and into the pipe, through the manifold, and then into the jugs, I bet the cylinders are nice and scored. Seems that there wasn't any water flowing anywhere. There must be an issue with the water supply from the pump as the water regulator is fed directly from the engine feed line. The regulator then feeds a metered amount of water to the water box and the tuned pipe.

 

[Minnetonka4me]

I was thinking if a guy just ran and ran and ran it with a blown regulator maybe it could get that bad. But..I agree its hard to think the motor didnt get damaged.

As far as the sound...think of one of those metal ball things people (bosses) had on their desks. Thats the noise you are looking for. When you turn it a ball will go up and over the top of the crank, and clank into the bearing on the other side.

A slight clank is usually piston slap which is pretty normal.

 

[kicker]

yes I was thinking just piston slap as well. Definitely not a clank. So now I am a little worried though. The compression is at 168 psi and 167 psi. The motor turns by hand very smooth.

Not sure what you guys can tell me after looking at the pictures, its hard to see.

Not to thrilled about tearing it down but better now then in June. The bolts have been removed from the heads at 1 point but the bottom end has not been touched. I am not sure if the heads were removed before or after the "cook out" The ski only has 112 hrs on it.

What would be the simplest cost effective way to tell if there is any damage that I should address before spring.

 

[Minnetonka4me]

Who knows maybe it had a transplant. I have baked a couple of motors w/o the bearings melting...and your motor looks pretty nice inside. I'd say let her buck.

 

[DA080682]

Who knows maybe it had a transplant. I have baked a couple of motors w/o the bearings melting...and your motor looks pretty nice inside. I'd say let her buck.

I would be concerned about the cages being brittle after all that heat. I agree, the top end looks pretty good from what we can see and the comp numbers are at least even.

 

[DA080682]

I was thinking if a guy just ran and ran and ran it with a blown regulator maybe it could get that bad. But..I agree its hard to think the motor didnt get damaged.

As far as the sound...think of one of those metal ball things people (bosses) had on their desks. Thats the noise you are looking for. When you turn it a ball will go up and over the top of the crank, and clank into the bearing on the other side.

A slight clank is usually piston slap which is pretty normal.

With a bad regulator, the stinger and coupling would be affected. Assuming their was water going to the working/non-working regulator you should still get water going to the box that would cool it, the exit hose, and the through hull fitting. I am suggesting that there was no water even coming from the pump to the regulator and the engine.

 

[racerxxx]

It probably was an old overheat and swapped like Minnetonka said. By looking at the manifold in your first set of pics, those jugs would have been discolored badly too cause that water is coming right by the exhaust ports to the manifold. If the safety pin has been removed from the grenade, she'll let you know. Run that mule!

 

[kicker]

Ok, I decided to just leave the tear down for the time being. But seeing how everything is melted or scorched from the stern all the way to the manifold, is there any way of testing the cooling without putting it in the water. It does not seem to me to be a "part" malfunction but rather a whole system kind of breakdown, which is what DA is referring to. (BTW whats a stinger and coupling?)

I know you can put a hose on it, but I am more concerned that the pump is not getting the water through properly. Also when using the hose attachment, to me, the water is going in on the "out" side of the heads, which would not give me a true indication if the jet pump is pushing water through the system properly.

 

[griz400]

looking at all the pics u posted , to me, looking at pistons (what u can see) looks good, and looking at the rear threw hull fitting, looks like actually you had water from cooling system, actually coming threw the little 90 degree fitting, or the whole "threw hull fitting" would be a complete meltdown, so, water from cooling system, just was blocked going threw the exhaust, looks like you'll probably have to cut the threw hull fitting out, with like a die grinder (cut off wheel) -- and the pistons look fair -to-good condition, i'd definately check the pump abd whole cooling system though !!!!:cheers:

 

[kwiktsi]

Pistons look pretty good to me. It's when they look like mine that you have to possibly consider a rebuild ...

 

[kicker]

looking at all the pics u posted , to me, looking at pistons (what u can see) looks good, and looking at the rear threw hull fitting, looks like actually you had water from cooling system, actually coming threw the little 90 degree fitting, or the whole "threw hull fitting" would be a complete meltdown, so, water from cooling system, just was blocked going threw the exhaust, looks like you'll probably have to cut the threw hull fitting out, with like a die grinder (cut off wheel) -- and the pistons look fair -to-good condition, i'd definately check the pump abd whole cooling system though !!!!:cheers:

Griz, same as you, to me it looks like some water made it back to the 90, but the wierd thing is that the water going to the 90 comes from the 2 fittings on the side of the block and that gets fed from the manifold on the other side. So if the manifold is that crispy and it is the manifold that feeds water to the pistons how did cool water get to that 90? Unless I am mistaken with how the water flows.

When you say check the pump, what are you referring to. I know the water is fed by the jetpump some how but not exactly sure how the water makes it way into the engine compartment. Just assumed there was a whole in the pump that split off into the hull.

I will start by taking off and replacing all the cooling lines, replacing reg. valve, and hopefully that will expose the problem with the water flow if there is indeed still a problem.

 

[racerxxx]

The pump sends the water into the WCV AND to the low side of the head. The head cools the head and the outlet on the front of the head cover feeds the tuned pipe through a brass fitting. The rubber hose is only about 6" long connecting the head to the tuned pipe. Check the head outlet is clogged and check the fitting, use a compressor to blow through with like 5-10 psi. This will feed INTO the exhaust manifold(your hot spot) and then flow into the cylinders, this will all eventually exit the high side of the head cover and out of the drain at the back of the ski and the cylinders will drain out on the on the lowside of the cylinders pass through a "t" and then go back to your exhaust elbow that melted. The WCV sprays water into the lower part of the tuned pipe to keep the exhaust cool thru the cone to the water box and also into the water box. And the only other line is the tell tale line coming off the top part of the exhaust manifold that will go back to your tie down ring. The manual has a really nice flow chart on this. If that head cover is plugged or the fitting that exhaust will get smokin'. I'd venture to say your probably Ok, I've seen a WCV lose a line before, and it ain't long before it will melt right off the brass fitting and be laying in the hull, another indicator that this may have been prior damage, all the blue goo holding the WCV together. You can blow air through the system, but physically inspect the WCV.

 

[kicker]

I was able to get it all stripped down and cleaned up, I did not find any blockages in the fittings or pipes. My conclusion is that whatever caused it to overheat has been rectified and any damage that was caused if any must have been repaired, except the stuff that got melted. I think the guy must have thought the blue RTV could seal everything.

thanks all, for your comments and help. I have a much better understanding now how the cooling system works.

 

[Minnetonka4me]

In my case, Ive had the line pop off the pump. What ends up happening is the hull is half full of water and the engine gets super hot.

Well...with all that water in there the engine transfers heat to the water. This happened to a brand new motor on the first ride in my back up ski about 6 years ago...and its still running fine. The funny thing is it didnt come off till the end of my break in tank.

That fawker happened 200' from shore and died just before I got to shore. Opened the seat and it was right up to the carbs, all the hoses had melted off. I pulled it up on shore, pulled the drain plugs and took a little nap while it cooled down. After 45mins I cut and reconnected the lines, climbed on, and she ran just fine....and still does.

When you have a plugged system and no water in the hull...thats when the real damage happens!