nissan 2000 NS40D2 EPTO2 rpm falls off

[hkcarbine]

While running about 3000 rpm the rpm fell to about 1500. Pulling throttle up and then down was able to run up to 3000. Then hit small wake and reduction happened again. Couldn't get rpm above 1500. Water outlet shooting out good stream. New premium non ethonal gas. Checked fuel filter under engine cover, no crud or varnish. No obvious loose wiring. What path to start down to resolve?
thanks for any and all advice

 

[Sea Rider]

Is fuel pick up filter located inside fuel tank clean with no debris obstructions. Is fuel tank immaculate clean. How about fuel connectors o´rings, are they dried, cracked, worn-out as to suck air when engine is running ?

You are looking at a 14 year oldie, Does engine runs smooth at 1500-3000 rpm ? If fuel circuit is in good working order could be a electrical related issue as a CD.

Happy Boating

 

[pvanv]

Diagnose the fuel and electrical systems. When was the last time the carbs were cleaned? Was it working OK up until this happened? Do you always run the carbs dry at the end of the day?

 

[hkcarbine]

Prior owner had carbs rebuilt last year. Only non-ethonal gas since. I had run boat 5 or 6 times with no problems. Cleaned fuel filters in tank and internal to engine. Internal fuel lines look new, suspect replaced when carbs rebuilt. Engine accelerated smoothly and ran good at all rpms prior. Will buy new fuel line between tank and engine. May be original with internal blockage due to ethonal gas. Will test when new line in hand! Keep ideas & thoughts coming!

 

[hkcarbine]

At last found time to work on motor. Replaced fuel line assembly from tank to motor. That did trick, in fact am able to get more rpms. Flushed with fresh water and ran fuel out. Good to go. Thanks for tips and ideas!

 

[Sea Rider]

Nice to read that worked for you, those small connector o'rings are not eternal, will dry out, wear out at some point. Find a real crime that you must buy a new brand fuel hose to solve gas related issues. Next time remove old ones, go to a car store and buy same diam & width, peanuts cost compared to. Run carb dry after each outing...

Happy Boating