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]

Re: Yamaha 200 V6 1993 Help

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

It is the valve the fuel line comes from.

 

[NICKW]

Re: Yamaha 200 V6 1993 Help

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

 

[blackbox]

Re: Yamaha 200 V6 1993 Help

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]

Re: Yamaha 200 V6 1993 Help

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]

Re: Yamaha 200 V6 1993 Help

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/showthread.php?t=283363

 

[NICKW]

Re: Yamaha 200 V6 1993 Help

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

 

[rodbolt]

Re: Yamaha 200 V6 1993 Help

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]

Re: Yamaha 200 V6 1993 Help

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]

Re: Yamaha 200 V6 1993 Help

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]

Re: Yamaha 200 V6 1993 Help

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 !!!!!!!!!!!!!!!!!!!