Need help <ECU replacement RPM Issue>

[cjssho]

Hello all. Need some help. Long story short my 05 sx230HO blew a ecu about a month ago. Installed a new factory ecu and replaced the #3 coil and put new plugs in it. Only able to get 8k rpms on that same motor. Any suggestions?

 

[MIDLIFECRISIS]

 

[mark_m]

Hello all. Need some help. Long story short my 05 sx230HO blew a ecu about a month ago. Installed a new factory ecu and replaced the #3 coil and put new plugs in it. Only able to get 8k rpms on that same motor. Any suggestions?

Check to make sure you plugged in all the coils. I had same behavior after changing plugs but didn’t fully click in the coil. This was an aha moment for me on the water and an easy fix.

 

[cjssho]

Coils are good. The problem started when I changed the ecu, then I did the coil, and then the plugs. So it was through all 3 phases.

 

[Scottintexas]

any basic idea on why your original ECU blew??

I think I would try a new set of plugs first, it's easy, we've had members with similar issues and a plug wasn't gapped correctly,

Do you have a YDS?

 

[cjssho]

No I don't have a YDS. I did send the ecu off to be fixed but came back unrepairable. I have tried 2 different set of plugs one brand new set yesterday and a old repair that were new at the beginning of the year.

 

[Scottintexas]

any idea what made the ECU go bad ?

we've seen a couple people with injectors that were stuck open, just guessing buy maybe it's flooding the cylinder and causing a misfire??

Have you checked your oil lately to make sure it's not overfilled or has fuel in it?

 

[cjssho]

No not sure the cause of the ecu. Gas and oil are fine. After replacing the ecu I did notice that #3 coil was bad and causing a misfire but I did replace that with new plugs.

 

[cjssho]

If this helps any the motor does seem to idle a little rougher then the other.

 

[zipper]

@cjssho Where are you located, there may be a member here with YDS that would run the diagnostics for you. I do agree with all that @Scottintexas said esp. about gapping. Is there a chance you were sent the wrong ECU, maybe for a non HO motor? Just bringing it up, It is the same wiring harness p/n for both ECUs. The numbers I looked up on Yamahasportsplaza are for HO's 6P6-8591a-01-00 and for non HO's it is 6B5-8591a-01-00. I do not know if it would even run with the wrong ECU, others here have a better knowledge of this. Another suggestion is to unplug each spark plug, only one at a time, maybe starting with #3 to see if it changes the idle/running for the worse.

 

[cjssho]

I'll try the the spark plug thing and see what happens. I did order my ecu from Yamaha sport plaza and part number was correct. My plugs are the ngk iridium so I thought that they came gapped to specs. Thanks for all the suggestions. Keep them coming.

 

[zipper]

I'll try the the spark plug thing and see what happens. I did order my ecu from Yamaha sport plaza and part number was correct. My plugs are the ngk iridium so I thought that they came gapped to specs. Thanks for all the suggestions. Keep them coming.

The plugs should be, but it is always good to verify gap. As @Scottintexas said it could be a stuck injector.

 

[itsdgm]

8000 rpm is normal range for a non-ho engine. I wonder if the factory mislabeled the ECU.

You could try swapping it to the other engine to see if it's for sure the ecu.

 

[cjssho]

I thought about switching them but as I've come to realize Yamaha did not make it easy to get to the ecu.

 

[Jgorm]

8000 rpm is normal range for a non-ho engine. I wonder if the factory mislabeled the ECU.

You could try swapping it to the other engine to see if it's for sure the ecu.

No it's not. 04 non ho image. Both did 10k on my test, one with low compression. My non ho mr1 ski does 9000+ on three cylinders.

 

[itsdgm]

I thought about switching them but as I've come to realize Yamaha did not make it easy to get to the ecu.

No it's not. 04 non ho image. Both did 10k on my test, one with low compression. My non ho mr1 ski does 9000+ on three cylinders.

maybe I should be more specific. You're right @Jgorm theyre actually 3 different variations of the mr-1 engine that I'm aware of. There's a 150HP HO, 130 HP & a 110 HP. My non-ho 110 hp engine that were installed in the 210 series boats have a max rpm of just above 8k rpm's. But it's quite possible that the wiring harness wouldn't even plug in to your ECU anyway @cjssho.

Anyway, hopefully you've figured it out by now. Best of luck with it.

 

[Roman Wiertelak]

Hello all. Need some help. Long story short my 05 sx230HO blew a ecu about a month ago. Installed a new factory ecu and replaced the #3 coil and put new plugs in it. Only able to get 8k rpms on that same motor. Any suggestions?

HALLO
Lately i bought YAMAHA SX 230 ,year 2005 ,with 2 engines .I'm looking for hole electric box with wires .because i have only one ,box is called YAMAHA 6B6.
MODEL of boat SRT 1100-D. VIN YAMCS384D505
Computer in the box has these numbers :6P6-00, F8 T94874, 5129
Outer computer has these numbers : SH 678B-13, G4D.3
Do you have something like that ?I can send pictures if you like .
Iam looking forward for your replay .If you don't have it ,do you know where i can find it ?My mail is roman@wiertelak.pl
Kind regards,
Roman

 

[Roman Wiertelak]

8000 rpm is normal range for a non-ho engine. I wonder if the factory mislabeled the ECU.

You could try swapping it to the other engine to see if it's for sure the ecu.

HALLO
Lately i bought YAMAHA SX 230 ,year 2005 ,with 2 engines .I'm looking for hole electric box with wires .because i have only one ,box is called YAMAHA 6B6.
MODEL of boat SRT 1100-D. VIN YAMCS384D505
Computer in the box has these numbers :6P6-00, F8 T94874, 5129
Outer computer has these numbers : SH 678B-13, G4D.3
Do you have something like that ?I can send pictures if you like .
Iam looking forward for your replay .If you don't have it ,do you know where i can find it ?My mail is roman@wiertelak.pl
Kind regards,
Roman