200 HPDI fuel starvation

[whoknows]

Hello All, I have a had a recent problem with fuel on my 2001 200 HPDI. It will not rev past 4300 RPM and falls on it's face past 75% throttle. At 4300, it only delivers 10.88 GPH. I have replaced all strainers, filters and cleaned out the VST screen, new plugs good compression, no alarms, no change. I also have the large blue Yamaha fuel filter/seperator. Thanks

[jb123]

first, try an auxillary tank with fresh gas to isolate motor from tank, as you could have clogged lines,air leaks, etc.
next check/replace low pressure fuel pumps.
after that most likely have to check fuel pressure after vapor tank.

[Hamfisted]

Do you notice if the primer ball is collapsing when this happens? Like a fuel flow restriction from the boat's fuel tank itself. Can you pump the primer ball firm with the motor off? If not I would also suspect your low pressure (mechanical) fuel pumps. Since you said you already changed all the fuel filters.
Other than that I'd have to hook it up to the Yamaha diagnostic system and read the motor's computer and sensors.
If you have a laptop you can buy the YDS kit yourself for about $250, and read all the stuff yourself. Do you have a service manual for the motor? If your email is posted I'll try to send you one.


-Mike

[tkgjax]

I purchased a used 2004 200 HPDI and am having the same exact problem. Purchased about 300 miles away so taking it back is a last resort. The old motor was getting plenty of fuel before blowing head gasket and eventually the power head and it was replaced within a month so unless it is a coincidence the problem is with the motor and not the boat. I cleaned VST filter and changed fuel water seperator. The new motor is under warranty but since I installed myself and depending on the problem not sure if it will be covered. Is there a easy way to check the low pressure fuel pumps? I would love a copy of the manual. If you could send to tkgjax@yahoo.com if would be greatly appreciated. Thanks!

[whoknows]

It turned out on mine to be several problems. I had a mixture of the old gasoline additive (in pump gas) MTBE and the new, Ethanol mix and settled into a nasty crystaline structure in the fuel system on the motor after sitting for while in the system. They replaced the high pressure fuel filter (cut it open and it was collapsed with less than 100 hours on it), a electric pump in the VST (showed a blue ring aorund the base and 5psi low on pressure) and one injector. Bring money for the injector (>$300 each)and pump ($700+). Cleaned the whole system out, backflushed the injectors and replaced the fuel strainers in the injectors, replaced the filters and seperator and the system runs about 18 GPH fuel flow versus 10 GPH before at full throttle. I will send a copy of the manual for you to your email address. Good luck. Brian

P.S. Yamaha is obscenely expensive on replacement fuel system parts!!!