Help.... 93 yam losing power in rough seas

[esteym]

Hi,


My Yam is bogging down in rough seas sporadicly. I have two theories, one that the fuel is reversing its flow as I pound through the waves (fyi the tank is midships and the fuel line is probably 15ft long and is below deck so I think it would have enough downward pull in rough seas to cause a reverse flow or slow it down.)

Or, the carbs have some particulates in them and when we go through the bumps it shakes it up off the bottom and causes a restriction. Only problem with this theory is that dropping it back to 6 knots would not reduce the suction enough to allow the particulate to drop away once it was picked up.


THoughts? I just don't want to pull the carbs apart if I dont have to. Can I put a inline fuel pump in to assist the pumps on the engine?

thanks!

Mike

 

[esteym]

Re: Help.... 93 yam losing power in rough seas

http://forums.iboats.com/showthread.php?t=131048 this thred seems to talk about the same problem.

I'll start with the carb rebuild since it is about time.

Then look at the water/fuel seperator drain it in a clear container - doubt it is this since we run alcohol in our fuel here and I have run 100 + gallons this year already.

Then I'll run a separate tank with seafoam or the equivalent to clean out anything I missed.

I have a relatively new tank - I hope that there is not gunk in the tank screwing things up

Let me know if you have any other suggestions

Mike

 

[jstavrakas]

Re: Help.... 93 yam losing power in rough seas

Two thoughts,

Check your water separator. If there is water in it, it may slosh around and get past the separator and cause the engine to hesitate.

I had a similar problem with a 250 HP EFI. There is a fine mesh screen in the high pressure fuel pump housing that filters out particulates. It was clogged up with a fine powder (this was a used engine and we were guessing the former owner's boat had an aluminum tank that created this powder). Long story short, once the screen was changed out, problem went away. This was difficult to diagnose because it only happend when we really hit the throttle hard or when the boat was running hard into a head sea.

JS

 

[Ray Neudecker]

Re: Help.... 93 yam losing power in rough seas

You can put an inline pump in as long as it will flow enough fuel at 6lbs or so. I would still go through the carbs and always replace the filter if I suspect a fuel problem.