Runs on land but not on water

I have a 2006 AR230. I just put new motors in on port and starboard side. I'm having the same issues on both sides, it would start and idle and run on both sides while on land with the hose running but when I'm at the docks and it's in the water, it has a hard time starting. If it starts, it'll idle but as soon as I give it throttle and back to neutral, it'll die and have a hard time starting again.

I have YDS and have no codes, I've set the TPS to be within value (no wake mode button works).

One ECU is brand new, and the other was rebuilt from regulator rectifier.

I've replaced both fuel pumps. Oil level seems good.

I bought the boat in 2023, my thinking is that while it's in the water, there could be load on the jet drive unit and there hasn't been any maintenance done, maybe I need to grease the or replace the cone bearings? Since 2023 til now, I took the boat out twice before both engines failed. Just finally got to putting new motors in.

While the boat is on the water at the dock and I get the engine running, I can leave the docks and it'll run while above idle speeds, it'll also get up in rpms no problem, but once I get it back to neutral, it'll die and have a hard time starting. If it's running on land and I blip the throttle, it'll still stay running, not when the same is done on the water.

If anyone has any suggestions, I would really appreciate it, I did read through the forum and found someone with a similar issue on one enegine. One person commented saying that the engine might not be running on all cylinders. I'll check my compression as the next step but it sounds like it is running on all 4.

Thank you

Be sure you do not have stale fuel in the tank

My engines weren’t new on my 08 AR230, but I had idle issues in the water upon first start up. I’d get off the trailer after throttling up and as soon as I’d go back to neutral one or both engines would die. Changed spark plugs in both and it helped the port engine but not starboard engine. Noticed one day the starboard engine idled about 150-200RPMs lower than port on land. Adjusted the idle screws to idle higher on both engines and never had the problem again.

Not sure if this is your problem but easy to adjust the screw! Be interesting to see your compression results and go from there.

Cobra Jet Steering LLC said:

Be sure you do not have stale fuel in the tank

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Thank you, I've emptied the tank and put fresh fuel in after dropping in the motors.

Hot2Go said:

My engines weren’t new on my 08 AR230, but I had idle issues in the water upon first start up. I’d get off the trailer after throttling up and as soon as I’d go back to neutral one or both engines would die. Changed spark plugs in both and it helped the port engine but not starboard engine. Noticed one day the starboard engine idled about 150-200RPMs lower than port on land. Adjusted the idle screws to idle higher on both engines and never had the problem again.

Not sure if this is your problem but easy to adjust the screw! Be interesting to see your compression results and go from there.

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Thanks, I've adjusted the screw, even used YDS to make sure it's within specs, when it runs, both motors idles just fine, new spark plugs as well.

Clogged injectors?

Maybe increase throttle at the helm and spray fuel in the intake with a sprayer to see if there's a change in keeping up with the rpms.

If more fuel keeps it going, is probably a fuel delivery issue.

Beachbummer said:

Clogged injectors?

Maybe increase throttle at the helm and spray fuel in the intake with a sprayer to see if there's a change in keeping up with the rpms.

If more fuel keeps it going, is probably a fuel delivery issue.

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I did replace both fuel pumps with new filter and pressure regulator. While the baskets were out, I cleaned the tank and vacuumed out all the debris. It's possible with the injectors being clogged. I did order a new throttle assembly that came with injectors for the starboard side so I don't think injectors are clogged on that side. But problem is occuring on both sides.

havewill22 said:

Thanks, I've adjusted the screw, even used YDS to make sure it's within specs, when it runs, both motors idles just fine, new spark plugs as well.

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So I adjusted my idle on both engines above spec. I think I had my engines running around 1600RPM, which I believe spec is 1300-1400? Either way when I’d get into the water under load the RPM was lower than what I adjusted it to on land. It’s very odd that you’re having issues with brand new engines though!

Also you have mr1 engines and if anyone overfilled the oil it ruins the air filters so be sure those are in good condition

Hot2Go said:

So I adjusted my idle on both engines above spec. I think I had my engines running around 1600RPM, which I believe spec is 1300-1400? Either way when I’d get into the water under load the RPM was lower than what I adjusted it to on land. It’s very odd that you’re having issues with brand new engines though!

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User manual says idle is around 1600rpm. Mines runs within 1300 to 1600, I've also brought my laptop and hooked up while on the water and it's within that range. If I adjust anymore, no wake mode doesn't engage.

Cobra Jet Steering LLC said:

Also you have mr1 engines and if anyone overfilled the oil it ruins the air filters so be sure those are in good condition

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Thank you, I've check air filters and they look good.