Yamaha 200 V6 1993 Help

[NICKW]

I Have Spent $5000 Trying To Get My Engine Fixed , It Hesitates On Acceleration With Throttle Fully Open, It Runs Around 28-33 Then Drops Down To 22-25 As If It Was Running On Five Cylinders I Have Had A New Exhaust, New Coil, New Water Pump, New Head Gaskests,new Thermostats, New Fillters,new Fuel Lines,two New Fuel Pumps , Carbs Cleaned And Blownout , New Spark Plugs , Compression Is Fine Also , With The Throttle Fully Open And Manully Pumping The Fuel Ball I Can Reach Speeds Of Around 38 Once I Stop It Will Drop Right Back Down Can Anyone Help

[sigma]

Have you looked at the anti siphon valve on the tank?????????

It is the valve the fuel line comes from.

[NICKW]

No I Will Look At And Let You Know , Do You Think It Might Also Be The Stator Breaking Down??

[blackbox]

this one should be easy! #1. use a portabil fuel tank and run the motor on it. if it runs o.k, the problem may just be in the boats fuel system.#2. use a clear 3/8 hose and a fuel vacume gauge at the motors fuel filter. a vacum of 4in. hg. or higher tells us there is a restriction in the system. if you see air bubbles in the clear hose, you may have an air leak in the fuel system. good luck.

[NICKW]

[QUOTE=blackbox;2376290]this one should be easy! #1. use a portabil fuel tank and run the motor on it. if it runs o.k, the problem may just be in the boats fuel system.#2. use a clear 3/8 hose and a fuel vacume gauge at the motors fuel filter. a vacum of 4in. hg. or higher tells us there is a restriction in the system. if you see air bubbles in the clear hose, you may have an air leak in the fuel system. good luck.[THANKS WILL TRY IT AS SEE]

[iammarcuse]

If you can get it to run by pumping the bulb then it is fuel not ignition. Have a look at this. http://forums.iboats.com/engine-frequently-asked-questions-faq/how-testing-your-boats-fuel-system-283363.html

[NICKW]

Thanks For All Of The Above, Done It All ,still Have The Same Problem No Change

[rodbolt]

by manually pumping the primer your bypassing the lift pumps.
have you actually tried trouble shooting as opposed to splatter gunning?
clear hose crap is just that.
use a decent vacum gauge t'eed into the lower lift pump.
should see at least .5"Hg and a max of 4"hg at the problem RPM.
what your describing is a lack of fuel to the fuel bowls.
and we dont care about speed, speed is totally irrelavent.
we need RPM information for technical issues.

[robert graham]

The primer bulb pumping should have been a dead givaway for fuel delivery/pressure issues and whoever you paid for that $5000 worth of "repairs" should be ashamed of themselves!

[ddowis]

You might want to check/clean the O2 sensor as well. O2 sensor will drop a cylinder (#1) if it is dirty or not functioning.

[NICKW]

Thanks To Everyone Who Replied Did All Of Above And Found Nothing Had Cabs Cleaned Runs Around 29-30 Now But Still Has A Hunting /serging Problem Still Need Help !!!!!!!!!!!!!!!!!!!