89 225 excel issues

[borkml]

Just bought a wellcraft 250 with a yamaha 225 excel. Motor has good compression and was semi rebuilt 2 years ago. It idles fine and will rev up all the way in neutral. However, under a load, when throttle increased, motor bogs down and struggles. Seems to me like its not getting enough fuel but I'm up for suggestions.

Also, motor still has the oil injection system. Does anyone know about these specific systems and if they are any good or should be pulled out? Thanks a lot in advance!

[boats.net]

It sounds like a carb problem you might remove and clean carbs(mark each carb and the float bowl so can be reinstalled the same way they came off and be carefull not to mix up main jets in carbs), check fuel pump diaphragms. The Yamaha oil injection is one of the best oil injection systems on the market.

[borkml]

Thanks, sounds good i'll take a look. I definately think it is starving for fuel since it is only under a load when you increase throttle that it bogs down.

[ginmills]

I have that same 89 Excel engine that came with the boat I bought. Same problem experienced.

Previous owner had installed an in-line electric fuel pump before the separator. With the pump off - could not even plane. Pump on - had no problems.

Researching this issue on other boards, it is recommended to bypass the quick disconnect and small filter assembly on the engine. Just use a quality Yamaha 10 micron fuel filter/separator instead. Apparently that small on-engine filter assembly was prone to restriction problems. Maybe this will help..

[Hamfisted]

Any kind of pump, either the hand primer pump or the electric fuel pump you have on your boat should be installed AFTER the fuel/water separator. The separator is not designed to have constant pressure on it, and Racors are only built to a 7 psi max pressure standard. If you absolutely have to have it (shouldn't) just put the electric fuel pump on the outlet side of the separator for safety. Some diaphragm fuelpumps act as a check-valve, or won't let fuel pass by if they're not running. So just turning the electric inline fuel pump off may not be a true indication of the problem. You may have to remove it completely and splice the line back together for a true picture of the motor's capability.


Mike