exhaust sensor issue?

[underwdr]

OK just curious if anyone has had an issue with a high temp alarm with wide open throttle. I have a 05 RXT with a Riva Stage 3 mod. Everything runs fine until I try to get over 65-70 mph range and then the alarm goes off. I have not really noticed an error code, but when I shut down and restart-all is fine again.
any ideas?:willy_nilly:

 

[ski-d00]

yes, that's a common problem, it's the blue sensor in the neck of the muffler(water box). the sensors are known for going bad and they are easy to test in hot water. but also the 3 small holes in the bottom of the j-pipe also can become clogged and restrict the flow to the muffler which will also trigger the h-temp exhaust alarm. the code is lost as soon as the temp comes down because it is no longer current, if you press set 5 times while it is going off it will give you the code or in BUDS it will show up as an occurred fault.

 

[underwdr]

Thanks for giving me some direction for this problem. How might I test the temp sensor in hot water? And how might I check for the plugged holes that you are talking about in the J pipe?
I appreciate your help!

 

[ski-d00]

The temp sensor (EGT) just changes the resistance at different temp levels. At room temp, it should be around 2500 ohms. you can put it in hot water to measure the resistance output. At boiling, 212 F, the resistance is around 160 ohms, and this is where the alarm is triggered.

Or, you can just change it since they are inexpensive.

The J-Pipe is connected to your exhaust manifold. To remove, unbolt the large clamp from your exhaust man and loosen the hose clamps on the exit side as well as the small hoses that connect to the exh man. slide it back as a unit with the mufflerto get it off the exh man, then pull out from muffler side. you'll see the 3 small holes on the muffler side that tend to clog up. you can clear these with water or compressed air.

 

[JFizzleJR]

OK just curious if anyone has had an issue with a high temp alarm with wide open throttle. I have a 05 RXT with a Riva Stage 3 mod. Everything runs fine until I try to get over 65-70 mph range and then the alarm goes off. I have not really noticed an error code, but when I shut down and restart-all is fine again.
any ideas?:willy_nilly:

What generation Riva intercooler is on your ski, Gen 1 (vortech) or Gen 2 (same as OEM X)? The Gen 1 Riva intercooler is notorious for clogging or leaking prematurely. Check that no hoses are kinked throughout the intercooler & exhaust circuit. As the other poster mentioned, you should check the small holes near the tip of the j-pipe. It's common to drill them out slightly larger for more flow. Loosen the coupler between the j-pipe and waterbox and slide it up to see the holes around the lower rim of the j-pipe.

The temp sensor (EGT) just changes the resistance at different temp levels. At room temp, it should be around 2500 ohms. you can put it in hot water to measure the resistance output. At boiling, 212 F, the resistance is around 160 ohms, and this is where the alarm is triggered.

Or, you can just change it since they are inexpensive.

The J-Pipe is connected to your exhaust manifold. To remove, unbolt the large clamp from your exhaust man and loosen the hose clamps on the exit side as well as the small hoses that connect to the exh man. slide it back as a unit with the mufflerto get it off the exh man, then pull out from muffler side. you'll see the 3 small holes on the muffler side that tend to clog up. you can clear these with water or compressed air.

I wanted to clear 1 thing up quick...The sensor is not an EGT sensor, as the 4-tec engine doesn't come equipped with one. It measures water temp as you referred to afterwards.

 

[ski-d00]

 

[Dennis]

SeaDoo does refer to it as a EGT sensor though.

 

[JFizzleJR]

SeaDoo does refer to it as a EGT sensor though.

That's quite unfortunate since they are only contributing to misinformation. Sure, there's gases in there, but there's a lot of water too!

When tuning the high HP (300+) 4-tecs with 14-38+ psi boost we put actual EGT sensors in the exhaust manifold to get true readings, which are in the 1600 deg. range, not 200 deg. like the waterbox sensor.

 

[Seadoobuddy]

OK JfizzleJr - You must work or own a shop. Name and location please to help our members.

 

[ski-d00]

I think he's a racer. We need more guys like that on here. I'm too old for that stuff anymore.

 

[Seadoobuddy]

That's what great about this forum. We have young people who bought a ski/boat last week, veterans who know a whole lot and racers who know about all the "cool" mods.

A small problem or a large mod, some one will know the answer sooner or later.

PS..whhhhhyyyyy won't my beeper work? :redface:

 

[JFizzleJR]

you guys should try to make it out to the hydrodrags nov. 4-6 in lakeland florida. it will be an eye opener for sure! watch at 42s into the video where the ski on the right gets a 2 second head start in an 8 second race (1/8 mile). that's a RXP-X in the right lane too, which is not a slouch by any means. http://www.youtube.com/watch?v=xiRGJmu0Xmc oh yeah, and the first "sanctioned" 100 mph run is at the end of the video. that will be topped once again (in competition) in 2 weeks

 

[underwdr]

OK guy's-back on track....I just want to say thanks to all for the info, especially sead00. I took the J-pipe off to check the holes you were talking about (ok-because I could do it tonight and it did not require an $80 part..I might be cheap!) anyway, whoever worked on the mods (best guess) overtightened the connecting hose clamps at the water box. This deformed the hose around the three holes to the point where it probably got to hot and continued to soften the rubber to where it sufficently impacted the water flow over time. I changed the hose and put it all together-not too bad for a first time working on these things (quite proud of myself-well sofar!) and am off to the lake to check it out tomorrow. If that is not it....Sensor!
Thanks again for the direction.

 

[underwdr]

Update to prior post: After testing unit on lake....and barely hanging on..... I am happy to say issue solved!!!!! Thanks again.

 

[gcooke3874]

The temp sensor (EGT) just changes the resistance at different temp levels. At room temp, it should be around 2500 ohms. you can put it in hot water to measure the resistance output. At boiling, 212 F, the resistance is around 160 ohms, and this is where the alarm is triggered.

Or, you can just change it since they are inexpensive.

The J-Pipe is connected to your exhaust manifold. To remove, unbolt the large clamp from your exhaust man and loosen the hose clamps on the exit side as well as the small hoses that connect to the exh man. slide it back as a unit with the mufflerto get it off the exh man, then pull out from muffler side. you'll see the 3 small holes on the muffler side that tend to clog up. you can clear these with water or compressed air.

Are the 3 small holes the "water packet holes?