Ls 2000 right engine trouble. Reduced power?

[holidayshoreslsboater1]

i recently bought a Yamaha jet boat that was in good condition. I am new to the jet boating hobby and I am having some trouble. The boat ran fine all day the other day. We docked it had dinner and went out for one last ride before dark. As we were heading out I mistakenly drove with only one engine running and ever since (not knowing if this caused the problem) I can not get the rpms to stay up above 4000. It's almost like its starving for power. It has no trouble until it hits above 4k rpm. It's almost like its staving for gas/power?As I accelerate the rpms decrease over time while the other engine is running perfectly. Help? I changed spark plugs and checked fuel filters. Also checked the jet area for debris.

 

[4x15mph]

I saw your other post and made some recommendations there.

- Check compression on all cylinders.
- Check that all spark plugs are firing and that each cylinder is running (install new spark plugs, idle, and then pull them to see that all of them have oil/black. If they are clean, the cylinder may not be firing/running.
- check to see if you are overheating which would limit the rpm's to ~3K

 

[holidayshoreslsboater1]

Thank you. I will give it a shot. I hope I didn't get water into the intake. I ran it trying to figure out what was going on. Possibly making it worse because of the water inside?

 

[Yamatuf]

I had similar problems last year, my plug wires were shot and would start failing at higher rpm. I used Jetski solutions for new wires and boots. $75 per side + freight. This will entail you to open the e-box and remove the coil packs/ wires. If you have the proper meter you can check the ohms.


If this doesn’t solve the issue it may be a carb problem, starving for fuel.

 

[adamculby]

How did you get the plug wires out? I can't figure out how to pull the ignition coils to send in the wires and coils for new wires.