300 HPDI Loosing RPM

[Tomba]

I have a pair of 2007 300 Yams 300 HPDI with 180 hours on them. (New To Me)

The issue I'm having is that I can curise all day at 4000 rpm but as I go over that after a while the port engine alarms and goes down to idle. If I pull back on the throttle and push back up it goes back up for a while and the same thing happens again.

I've changed all filters and impellers and even ran fuel from a protable fuel tank thinking its a fuel line issue but the same thing occurs.

Any insight on what to look for will be greatly appriciated

http://www.screamandfly.com/images/icons/icon9.png

[VectorPat]

Still sounds like possible water pressure problems. Do you have a water pressure gauge? These motors are very sensitive to it especially in a performance type set up.

[Tomba]

Thinking of modifying the lower units for low water pickup. Anyone know the part # for the conversion kit?

[ivan2214]

x2 on the water pressure ..if you dnt have water press. guages i suggest you get some . how do you like the 33 avance??

[Tomba]

Thanks Pat and Ivan

I do have water pressure gauges. And they are reading normal during the testing.

I've only had the 33 advance for about four months now and have only been out on it a hand full of times. She's a real eye catcher an fun boat so far other than this issue I'm having. It's gets up to 64 mph before the alarm and losing rpm. So I'm really anxious to see how fast it will go running at the full 5600 rpm.

Any pics of the Carrera?

[Superbender]

Can you take close up pictures of the water intake screens?

[Tomba]

235956

235957

[VectorPat]

When you say water pressure is normal, what pressure is it? Superbender brings up a good point, those are the standard screens, they do make other "dynamic" screens that my help get more water to it. Also make sure there is nothing mounted on the hull in front of the gearcases like a transducer or livewell pick up.

[Tomba]

(what should the water pressuer be reading?)

Nothing infront of the gear casings.
We hooked up the engines to the computer and saw the alarm but no code.

Any online stores for the "dynamic" screens.

[Superbender]

I can send them to you but you have to answer Pats ques.how much water presure,also what kind of steering are you running and whats your toe measurement -/+.

[Tomba]

Toe Measurement? Please explain.

We are testing the boat again today. Will post pics of the steering and the water pressure guages while running.

R.

[Darkside's Calling]

toe is the inward or outward angle of the lowers realitive to each other.

Toe'd in: both angle in towards the front of the boat.

Toe's out: both angle out from the front of the boat.

Same as with the toe-in setting on your car or truck frontend alignment.

[Superbender]

too much toe can cause overheating