1994 Yamaha 225 Stalling During Acceleration

[scarab30]

I recently purchased a 1994 30 ft Scarab Sport w/ twin 1994 Yamaha 225 hp saltwater series 76 degV outboards. Motors have approx 530 hrs each. Both motors generally run fine with the excption that the starboard motor has a tendency to run rough, bog and stall when accelerating from idle after the motor has been operating for a while. The motor can be made to run if the throttle is pushed all the way forward, it will hesitate slightly then accelerate. I have already checked & changed spark plugs, and both the onboard and remote fuel filters. I'm thinking my problem is with the carbs, maybe some fouling or a sticking float, but I wanted to get some opinions before I go any further. Additional note, the motor that is having this problem seems to be harder to prime than the other one, i.e. it is difficult to fill the onboard motor fuel filter bulb with gas completely by using the primer bulb?

 

[rodbolt]

Re: 1994 Yamaha 225 Stalling During Acceleration

hello<br /> the 76* motors had some uniqe features for acceleration. the fuel pumps need to be replaced about every 3 years,they get old and tired like me. test the engine compression then all the spark plug caps. yamaha had some stator issues back then so do a hot running charge coil output test to insure proper CDI output voltage.the TPS also sends throttle valve position as well as motion to the computer. on rapid throttle opening the computer will change timomg as well as add fuel through the six valves on the carbs. if #6 fuel bowl is not full it will suck all the fuel from the bowl and bog. that is why those engines have to have perfect fuel pumps.<br /> you may wish to find a tech that is familiar with your engines.<br /> good luck and keep posting