Gas in Exhaust / Oil in Starboard Engine

[iTzTPATT]

Hello all. Fairly new Yamaha owner of a 2005 AR230. Has run like a top the past 2 seasons but recently noticed gas leaking through the exhaust, and after pulling the spark plugs noticed oil in the Starboard engine.

Both engines were still hitting 8-9K RPM no problem as recently as last weekend, but shut it down after noticing the gas leak.

Any thoughts on what my issue may be? Thanks in advance for the insight/help!

 

[Farny]

Hello all. Fairly new Yamaha owner of a 2005 AR230. Has run like a top the past 2 seasons but recently noticed gas leaking through the exhaust, and after pulling the spark plugs noticed oil in the Starboard engine.

Both engines were still hitting 8-9K RPM no problem as recently as last weekend, but shut it down after noticing the gas leak.

Any thoughts on what my issue may be? Thanks in advance for the insight/help!

Check injectors & ECM

 

[iTzTPATT]

Thank you. Would the YDS accomplish both of these? Plan on doing that next once I find my kit.

 

[scokill]

Check your oil level. If an injector is stuck open and gas going into oil it will thin it out and could cause catastrophic engine failure.

 

[Farny]

Thank you. Would the YDS accomplish both of these? Plan on doing that next once I find my kit.

YDS Not necessarily - really need to perform physical injector test

 

[kjr6306]

Just to clarify they are suggesting that you have a stuck open fuel injector that is pouring fuel into your cylinder/s. The fuel makes it past the rings and contaminates the oil. This is a somewhat common problem due to corrosion in the ECM.

 

[Farny]

Sometimes seafoam will clear it up. Do an oil change, run Seafoam, see if that clears it up.

 

[iTzTPATT]

2004 AR230

Thank you all. As an update we had someone come out and look at the boat. Looks like the previous owner had too much oil in each engine (similar to many other threads) which explains why we may have come across some in the pan.

Did a full oil change.

Seemed to fix the issue for the first 20 minutes but then the gas in the port exhaust returned.

plugged in YDS for both engines. Injectors all clicked as I assume they should 20 times.

would this lead you to believe it is the ECU? If so, is there another thread on how to access it? I’ll try to swap ECUs and see if that is my problem next if that is the recommended course of action.

good news,
finally was able to read the hours. 156 on each engine on a 2004 AR230. Lack of run may be a little worrisome, but better than the alternative I hope.

 

[Beachbummer]

I don't know if on your boat it may be easier to swap injectors or ECU to test/diagnose. It's one or the other likely. Sadly the YDS test was inconclusive. Did the oil level increase again? does the oil smell like fuel? Does the engine run fine otherwise at low RPMs?

 

[iTzTPATT]

Did not notice fuel in the oil. Engines both honestly run/start fine, and would argue the port motor with the tbd gas leak runs better than the starboard.

will try to swap ECUs this weekend to see if that is my issue. I’m assuming it is in the black box on the rear behind the motor? Looks like the four bolts are accessed via the clean out hatch on the back of the boat. Any other tips/tricks I should know before I unbolt both and swap?

 

[Farny]

Did not notice fuel in the oil. Engines both honestly run/start fine, and would argue the port motor with the tbd gas leak runs better than the starboard.

will try to swap ECUs this weekend to see if that is my issue. I’m assuming it is in the black box on the rear behind the motor? Looks like the four bolts are accessed via the clean out hatch on the back of the boat. Any other tips/tricks I should know before I unbolt both and swap?

Even though the injectors may be clicking, it could be a clogged injector flooding the piston. Did you perhaps try either an injector test or sea foam? You can test your injectors by putting a water bottle over each and see if it is leaking.

 

[Farny]

Did not notice fuel in the oil. Engines both honestly run/start fine, and would argue the port motor with the tbd gas leak runs better than the starboard.

will try to swap ECUs this weekend to see if that is my issue. I’m assuming it is in the black box on the rear behind the motor? Looks like the four bolts are accessed via the clean out hatch on the back of the boat. Any other tips/tricks I should know before I unbolt both and swap?

Advice from @finnrigged

It is very likely a stuck fuel injector from one of two reasons. Old/dirty/ ethanol gas can clog them up sticking in the open position. The other common reason (but not common with the 1.8) is a bad ECM. The fuel injector relays in the ECM can go bad and has to be replaced (used one off eBay is your best bet). So...now is it really a stuck injector? The way to find out is a 2 person job. Leave spark plugs IN. REMOVE ALL SPARK PLUG QUICK CONNECT WIRES ON THE 4 COIL PACKS . Hope that helps.

The ONLY way I know of to test if this is just the injector sticking in the OPEN position is this:

You would remove the fuel rail, zip tie each of the fuel injectors to the actual rail to keep them in their place. Then, KEEP ALL SPARK PLUGS IN THE ENGINE.... but MAKE SURE TO DISCONNECT ALL OF THE SPARK PLUG QUICK CONNECT WIRES.

Take 4 empty water bottles and secure them somehow so that the tip of each fuel injector is inside the opening of the bottle to catch the fuel as it sprays out. NOW:

Just blip the starter by turning the key for that motor. This will "actuate" the fuel pump for that motor and fuel from the fuel injectors should AT MOST spray for a fragment of a second. If one of them stays open and continues to spray gas into the bottle then it will stop after about 10 to 20 seconds so don't worry. Just let it time out. YOU ARE NOT TRYING TO START THE MOTOR...just blipping the start key to get the fuel pump to actuate for like 1 second max. Now.,..IF one or more of your fuel injectors continues to spray gas for a sustained few seconds instead of just a fragment of a second...you swap the stuck ones with the ones that are not stuck and do it all over again. If the re-located stuck injectors continue to spray gas in their new positions (where no gas kept spraying from the first time) then you just have dirty or broken injectors. Go get them cleaned at a high preformance motorcycle or auto shop OR www.injectorRX.com is a great place you can send them off to in the mail here in Houston.

IF the first test "stuck" injectors do not stick on the second test and if the previously un-stuck injectors now continue to spray gas...then it is your ECM that is bad and will need to be re-programmed with new fuel injector relays installed inside. There is a company out of california that does this. They charge $80 to diagnose and if the ECM is bad and you decide to have them fix it it is a total of $400 plus shipping (they credit you the $80 from the diagnosis). Hope this helps...it should get you there.

 

[iTzTPATT]

Thank you very much for the response and detail! Learning on the fly here as a first time boat owner. I now know how I’ll be spending my Saturday in the TX heat.

 

[Farny]

Thank you very much for the response and detail! Learning on the fly here as a first time boat owner. I now know how I’ll be spending my Saturday in the TX heat.

Credit to @finnrigged for that. Copied his advice to me

 

[Murf'n'surf]

Bad injector(s) can cause damage to the ECU by causing high resistance. So, you should ohm out all of your injectors to see if you have a bad one. And then get the ECU checked out/repaired. There is a company that does both but I don't remember the name. I would not switch ECU's between motors and possibly cause damage to the other ECU.

 

[Murf'n'surf]

www.injectorrx.com

Injectors should be at 14-15 ohm @ 68 degrees

https://jetboaters.net/threads/mr1-issues.38022/#post-608641

 

[Beachbummer]

A lot of the reported damage is related to water in the ecu. Check for that too, that the ecu box is not full of water.

 

[iTzTPATT]

Hello all appreciate all of the help this far. As a quick update, I finally got around to the boat this afternoon. After reading the post, and other comments on the forum I started with the ECU box. Sure enough, after learning how to take that apart and open I did have a decent amount of water in the box. Safe to assume that is the issue and send it off to the California company for repair?

 

[Murf'n'surf]

Hello all appreciate all of the help this far. As a quick update, I finally got around to the boat this afternoon. After reading the post, and other comments on the forum I started with the ECU box. Sure enough, after learning how to take that apart and open I did have a decent amount of water in the box. Safe to assume that is the issue and send it off to the California company for repair?

Thanks for the update! Yeah, try the repair of ECU. Not sure they are repairable after water damage….might want to contact them before you waste time and shipping cost.

 

[Beachbummer]

And if you proceed with a repair be sure to ask ALL drivers be replaced. We have had members repair the one damaged, to have another one bite the dust a few months later