Suzuki 4 stroke bogging down

[TikiDoc]

Greetings all.  I need help with a fuel issue - 2011 Suzuki DF250.  Starts easily and idles fine.  I am running it in water under my lift.  Recent change of fuel lines, separator and primer bulb (OEM Evinrude brand - I heard they were among the best).  Accelerates in neutral to about 2900 RPM, but will not advance past that.  I started chasing down all components - bypassed separator, opened fuel filler, etc. - all with no change.  Finally, I ran it with a portion of (new) fuel line in jerry can of new gas.  Only possible element to allow air into the system was the bulb, which appears fine.  The curious part is after I pump the bulb a couple of times, it gets firm, but every 30-45 seconds, I hear a whirring sound from the fuel system of the motor, like its trying to purge air or fuel vapor.  When this happens, the bulb immediately goes soft and I can feel gas bubbles bubbling within the bulb.  Small amount of air gap noted in engine fuel filter when this happens that clears after couple of pumps of the bulb, only to have the cycle repeat in another 30-45 seconds.  The only possibilities I can think of are a bad primer bulb right out of the box that is allowing air in, a leaking connection at the bulb (which I haven't found) or something in the fuel system of the motor.  Wild idea - something about running in idle that limits it.  No alarms and tach/tach idiot lights/beeper appear to be working normally. To anyone who knows Suzuki - HELP!

Thanks in advance,
Blake

[Tampa Bay Mike]

They have a rev limiter when in idle. Sounds like that's all it is.

[Nates 86 200]

Sounds like its time to call in the pros. You can chasedown those problems and still never figure it out . I chased what I
Believed to be fuel problems  on a yamaha fourstroke it ended up needing a new computer. Best move I ever made was calling in a certified yamaha tech. A little money spent means you can get out and enjoy that lovely motor. Just my 2 cents.

[gaudzilla34]

Just throwing out some ideas with out seeing or knowing what you replaced.

-grey fuel lines have plastic liner inside could be small block at one of your connections, tank to primer to motor.  If used grey hose take apart connections and check inside fuel line for that.

- primer ball too high not enough hose losing prime when in load,  may need to add line from water fuel separator to prime ball. 

Last but not least coast Gaurd purge valve on fuel tank.

Hope it helps good place to trouble shoot.  Also I know Yamaha engines are very particular to which primer ball you can use.  So that would be another place to check.  Good luck been there before it gets frustrating fast.

[TikiDoc]

Thanks for the input guys.  Unfortunately, I'm dodging another hurricane today.  Like I said before, last time I investigated, I ran straight out of a jerry can with new hose and primer bulb with the same results.  So I know its not the tank pickup or check valve or anything like that.  It used to have the gray hoses and a cheap Atwood bulb when I got it.  I removed all this stuff when I first noticed problems and the line is all high quality Sierra.  I hope to look at it again this weekend.  Any ideas on something else to check?  Otherwise, its time to pack it up and take it to the mechanic.

Thanks,
Blake