GTX RFI runs great but end of pipe still gets too hot

[hoovler814]

Hey there! I bought a 99gtx rfi that came to me with melted resonators and also blistered exhaust couplings. So far I've done the following and haven't got to ride more than 15-20 mins at a time(The pipe at the coupler side before the waterbox gets TOO hot and I can start to smell the rubber start melting)

1. Compression is dead perfect at 150 each hole. It has 245 HRS on it
2. Epoxied the holes in the resonators(holding well for now)
3. Removed the water regulator and checked for bad bellows, operation, etc.
4. Used compressed air to blow out cooling system.
5. New voltage reg, as it would charge when it wanted to. New battery as well.
6. Relocated tell-tale to the battery vent hole on the left of boat so I could see it better(always a stream coming out when on water or the hose)


It runs GREAT...I hit low 50's on the lie-o-meter...The end of the pipe just won't stay cool after a 1/2 mile WOT run.

This is where it gets embarrassing. I'm a small engine tech and auto mechanic and I restore old vw's and work on my own Boxster and this ski is just kicking my ass..I even work on a few skis at work(mainly wear rings, etc).

Should I just spend the money on a new water regulator and be done with it? Anybody think of anything else I need to look at? I just didn't see anything wrong with mine when I disassembled it. I'm lost...Anybody have any thoughts given the symptoms?

 

[racerxxx]

You can adjust the cap on the WCV (water control valve) on the water box and that should regulate the water into the pipe to cool it. I remember a few good threads on it here, probably in the service manual too.

 

[hoovler814]

The way it's set isn't flush...I've read threads on both a turn or two in and also set flush. Not sure which setting applies to mine..

I always have water out the tell-tale so that tells me it is indeed cooling correct?

Just not enough apparently and the regulator may be working but just not correctly?

 

[racerxxx]

The tell tale tells you it's flowing water thur the engine, the WCV injects water INSIDE the pipe to cool the hot exhaust gasses. Either your WCV is adjusted wrong or it bad, or you have an obstruction in the line or a corroded fitting into the pipe. Possibly.

 

[hoovler814]

i took all the fittings off and I'm doing it again right now just to make sure they're all still clear. I couldn't find any blockages before when I checked. If all looks good I'm going to just buy a whole new regulator. When I pull the line off that heads to the pipe it has a nice stream and I thought that meant it was working properly.. i dunno..frustrated.

 

[LouDoo]

I'm betting you need a new bellows in the water control valve, even if there's not a hole, they get weak over time.

Lou

 

[hoovler814]

I just disassembled the WCV again and I'm going to order a new bellows just because. It's developing a pin hole in it that doesn't actually go through but it does seem weak....The part will be ready for me when I get back from the beach and I'll take it to the lake again and see how it goes and report back. Thanks all.

Kris

 

[Sportster-2001-951C-Stock]

Since you are a mechanic, I just wanted to mention on the water valve cap, the more you screw it in, the more you screw it off.

Or perhaps better said, the more tension on the spring, the later it moves up to restrict water flow to the cone pipe. At least that's how mine works....

I would also check the hose going from the valve to the pipe, for obstructions.

 

[hoovler814]

Sportster everything is freeflowing. I get plenty of water out the pipe. I am going to set it flush for the next ride with a new bellows. It was just one turn spun in. Other than that it runs great. It's too big of a boat for me....I got a clean ski and trailer for 800.00...He thought he blew it up when it overheated. I can't complain too much. It's a little different than building shortblocks and the random car work i do daily. It's a fun learning thing. My mind is always hungry. You got to learn something everyday to be healthy.

 

[Sportster-2001-951C-Stock]

Sportster everything is freeflowing. I get plenty of water out the pipe. I am going to set it flush for the next ride with a new bellows. It was just one turn spun in. Other than that it runs great. It's too big of a boat for me....I got a clean ski and trailer for 800.00...He thought he blew it up when it overheated. I can't complain too much. It's a little different than building shortblocks and the random car work i do daily. It's a fun learning thing. My mind is always hungry. You got to learn something everyday to be healthy.

Yep, it sounds like there's insufficient quantity of water in the pipe, but since the resonators were melted as well, then insufficient water in entire exhaust, maybe. So, there could be a restriction in the water flow going to the waterbox valve, maybe?

Just thinking out loud.....

http://fiche.seadoowarehouse.com/se...sp?Type=18&make=seadoopwc&a=245&b=13&Action=O

 

[nmpeter]

Yep, it sounds like there's insufficient quantity of water in the pipe, but since the resonators were melted as well, then insufficient water in entire exhaust, maybe. So, there could be a restriction in the water flow going to the waterbox valve, maybe?

Just thinking out loud.....

http://fiche.seadoowarehouse.com/se...sp?Type=18&make=seadoopwc&a=245&b=13&Action=O

I have a melting rfi as well. water is flowing well, plenty coming out of the exhaust. Knocked heads around and came to a running lean theory.

gas was questionable, so it's been drained and I've eliminated the resonators with a couple of bits of custom bent exhaust pipe.

at the last meltdown it lost the long and port resonators and get this..the theory is a lean condition is allowing superheated exhaust gas to burn holes in the resonators at key locations( both sets blew out in the same place. I suspect at one time somebody dumped a entire can of some kinda snake oil in this gas to clear and injector problem and the ski has never run long enough to burn that gas off. now months or maybe years later that gas is like 75 octane with a good dash of ethanol

at least now if a hose melts its not costing me big bucks for parts, next time I'm going to try to make a single pipe solution. I did pull the pump and check the sock. all looks good. If its injectors or the fuel pump the owner is going to turn it into a reef. Things been a money pit since the week he came home with it.