Why does my jet boat keep stalling?

Question

when I run my boat full throttle it stalls after 30 seconds. it runs fine at 80% throttle or less but when I go full speed it stalls. I'm able to turn it back on after about a minute. I already changed my fuel water separator filter which made it run a little better. what could be wrong?

Answer 1

Please,could we have a little more info. eg.

1) make and year of the engine

2)model etc

I'm going to guess but I think you have a newer engine with fuel injection.

If you like you can contact me through this site and I will try to help you along.

35 years as Master marine tec.

Answer 2

It looks like a replacement engine. Can you describe the outdrive or post a photo of it?

Answer 3

It's the fuel pump,

The rubber inside goes bad after awhile and can't keep up with the demand for fuel at wide open throttle.  If you have a Holley electric fuel pump there is a rebuild kit for it.  A new pump is around $180.00 but you can get a rebuild kit from Holley for about $35.00

Be sure to use a pressure regulator if needed.  And use marine grade everything.

I just did the same repair on my boat less than a month ago, with the same symptoms and it runs great now!

Answer 4

hi there...... check the  high speed jet on the carb.  the carb is probabily dirty.  

If its running well at  80% then  I wouldnt think that its your engine going bad.

I am more inclined to think that its either your carbs need cleaning.  

It may be the coil too... and at high revs it shorts..  

Go with the carbs first or if its fuel injected try cleaning the injectors.

Also is it a 4 stroke or two stroke.  Either way drain al the fuel out and make sure the whole fuel system is clean and start again with clean gas.  If two stroke make sure the oil gas ratio is correct.

You will see on many sites that outboard bog and die at full throttle and it is usually the carbs because they need cleaning.

Check out iboats.com   they have forums where you can as questions.