SX230

[Jason4356]

Just picked up a 2004 SX230 for a pretty good price. Did an oil and plug change and gave her a good cleaning and put her on the water. Engines started perfectly. No wake cruising is as expected. Once I got her to the point where I could see what she was made of, I discovered the starboard engine was lacking in power. It will only hit about 6000 RPMs. Then it will fluctuate between 4 and 6000. Otherwise it seems to run fine as long as I keep it around 4000 RPMs. I've read through many posts about ECMs/ECUs etc etc. So, am I thinking correctly that it may be related to the ECM on the starboard side? Hate to toss out 13-1400$ blindly. But, it wouldn't be the end of the world if I did. Also, I think I'll swap the port and starboard ECMs to verify. Any other ideas or thoughts? New to the forum. Its great to see it is active and has a ton of great info.

 

[WREKS]

I would get a service manual and check injectors, and coils for specification: then compression test. Do some of the less expensive things first.

 

[Jason4356]

Thanks. I was reading up on that in some of the other posts. Thanks for the reply.

 

[Looper7]

Welcome and congrats on the boat

 

[Jason4356]

Thanks

 

[Julian]

There is a place that reconditions ECUs. @bronze_10 has info.

 

[Beachbummer]

I believe YDS injector clicking test can help diagnose. Generally if it;s ECU it will run at or around 8K OK, but who knows...

Also, opening ECU case and finding it water filled is a bad indication.

 

[mark_m]

Just picked up a 2004 SX230 for a pretty good price. Did an oil and plug change and gave her a good cleaning and put her on the water. Engines started perfectly. No wake cruising is as expected. Once I got her to the point where I could see what she was made of, I discovered the starboard engine was lacking in power. It will only hit about 6000 RPMs. Then it will fluctuate between 4 and 6000. Otherwise it seems to run fine as long as I keep it around 4000 RPMs. I've read through many posts about ECMs/ECUs etc etc. So, am I thinking correctly that it may be related to the ECM on the starboard side? Hate to toss out 13-1400$ blindly. But, it wouldn't be the end of the world if I did. Also, I think I'll swap the port and starboard ECMs to verify. Any other ideas or thoughts? New to the forum. Its great to see it is active and has a ton of great info.

Double check that you re-plugged in all of the coils after your plug change. I missed a plug once after a change and had a similar situation.

 

[Jason4356]

Thanks for the tip. I did check after I changed. One felt a little questionable. But, it was on the Port side motor, which is running perfect. Did some tinkering with it last night and gonna put it on the water today and do some more diagnosing this evening. There were no air filters installed, which after reading through other threads, it may not be that big of a deal. So, im running filterless at the moment.

 

[mark_m]

Thanks for the tip. I did check after I changed. One felt a little questionable. But, it was on the Port side motor, which is running perfect. Did some tinkering with it last night and gonna put it on the water today and do some more diagnosing this evening. There were no air filters installed, which after reading through other threads, it may not be that big of a deal. So, im running filterless at the moment.

Got you. I think looking at ECU is your next step then. Good luck and keep us posted!

 

[Jason4356]

Will do. And thanks to everyone for the replies and advice so far.

 

[Scottintexas]

glad to have you on board, update your profile with your location so we know where you're at.

confirm your oil level, air filter is clean and I would change the spark plugs again, the mr1's are very picky about plugs for some reason, I had an engine topping out at 7k rpm, changed the plugs and it worked fine,

.

 

[Jason4356]

Thanks for the info. Hard to imagine changing out new plugs for new plugs. But, if they're that picky, then it's worth a shot. Better to rule out all possibilities before spending big money. Especially as cheap as something as plugs.

 

[Jason4356]

Quick plug change and she's running top notch! Thanks all!

 

[GTBRMC]

Glad to have you onboard! The MR1s are super spark plug sensitive but they are otherwise outstanding engines. You will love them. Best of luck and don't be shy asking questions here. If it can happen on a jetboat, somebody here knows how do deal with it. Cheers!

 

[Jason4356]

Thanks again everyone, for the welcome and the advice/tips. Pretty sure I'll be spending lots of time on here...when I'm not on the water.

 

[Gym]

Welcome aboard @Jason4356. While I do agree with all previous advice and at the risk of repeating some I would suggest you start with low & no cost items first.
1) Make sure you are using NGK CR9EB spark plugs gapped to the closer tolerance.
2) swap plugs between engines to see if trouble follows
3) check oil in under performing engine. If oil level high, smell for gas. This could indicate a dirty injector or one staying open at the request of the ECU. A dirty injector may be resolved with 5 cans of Sea Foam in a full tank of gas. If not you can send your injectors out for service.
4) If no luck with plug swap try a coil swap.
5) a compression check can easily be performed during a plug swap.
If no luck with the previous steps go for:
6) Swap your ECUs.
One of the above steps will definitely expose your problem. Hopefully you don't need to go beyond step 4.

 

[Jason4356]

Thats a spot on "check list". Keeping that in the record book for any future issues as an order of things to perform if the problem should arise again. Thabks Gym. Took a gamble on this boat as they are hard to find at the moment. So far, it seems to be as good an investment as a jet boat can be. So, I'm left with a few thousand in the budget for some upgrades soon.

 

[J-RAD]

Congrats on the boat! I'm glad you got her running smoothly. Have fun out there!

 

[Jason4356]

Congrats on the boat! I'm glad you got her running smoothly. Have fun it there!

Thanks. I plan on it.