2001 Suzuki engine

2001 Suzuki 4 stroke engine runs rough after 3000 rpms, any suggestions? have tried new fuel

hi john, kindly tell me what kind of roughness like is it jerking or sound a lot or something else, it will be better to fixed the problem. but my suggestion is
check the fuel line and fuel filter. Thanks Francis

sounds like yoour in rpm reduction mode

First off, these 4-stroke models are very picky about spak plugs. You may have already changed them, if not now would be a good time. You don't need to go to a marina, the auto parts store will have them tomorrow for $3/ea. RPM reduction kicks in at 3000 RPM as a protective measure if something is wrong (low oil, overheat, etc.) but should be accompanied by a beep or a light if you have a Suzuki tach. I have seen varnished or contaminated injectors cause this type of problem as well. They can be removed and cleaned, I would not advise pouring fuel injector cleaner into your fuel. You may also want to drain the VST to see if you find water or contamination. Look behind the intake manifold and you'll see an aluminium tank with some hoses and wires going to it. This is the VST (Vapor Seperator Tank) it houses the fuel injection pump. At the bottom of this tank there is an 8mm bolt that is also slotted to accept a screwdriver. This is the drain screw, don't take it out just back it up until fuel comes begins to trickle out from a nipple below the bolt (the nipple should have a pink hose connected to it but they often fall off). You can also drain your fuel injector rail via the Large bolt on the bottom that holds the fuel fitting wich looks something like a ball joint. This part is pressurized so loosen it slowly and be ready for a squirt! I think you just need plugs and if it still runs the same then clean the injectors. If you're up to it I could better explain the injector cleaning but I need to know the model. If you happen to have a carburated engine that's a whole other story. Best of luck, we'll get it.