Sorry if a boat engine is out of the scope of this forum, but I was hoping you might be able help with an issue I am having with one of the engines on my 2013 Yamaha 242 Limited S boat. It has two 1.8L engines in it and on one of them at just over 5000 rpm, it will surge and go to 6000 rpm. It doesn't fluctuate up and down, it stays at 6000 until I move the throttle. It runs fine at 5000 and below, and at 6000 and above, but I can't get it to operate between 5 and 6. I changed the TPS sensor and spark plugs but the problem still exists. Would you have any idea what might cause this issue? The other engine runs fine, no issues at all. Both engines have about 100 hours on them. Thank you.
If it only acts up between $500 and 6,000 RPMs not below and not above that generally means you have some type of problem with the fuel system at that particular RPM spring. I'm assuming it's fuel injected you could try cleaning the fuel injectors. If it's carbureted. The carburetors would need rebuilding though
