RPM loss after one hour Excalibur 343

[-nico-]

Hi

Im french and my name's Nicolas

first sorry for my english!!

your forum is great !! a lot of informations are available!

I have a Super air nautique 210 2006 with a 343 Excalibur PCM 5.7L

I bought this boat in April with 630 hours and after 20 minutes of running the first time the engine Explode!!

diagnosis by the dealer: engine out !! water in cylinders, a rod disassembly cause two 5 centimeters hole in the bloc

so I obtain a new bloc engine, under warranty....

I m in the first 25 hours of running and I take care of my engine

during 20 hours everything was perfect and the two last times , after one hour of wakeboarding at 2500/2800 RPM, I have a loss of RPM few seconds with a return at the normal RPM

If i stay at cruise RPM the loss is bigger

If I stay at IDLE few minutes I can restart normally at 2500 but the cycle come after a moment

all gauges are normal, no suspect noise, engine run perfectly....


My dealers says me "fuel filter"!

I change it directly: I open the FCC, the old filter was dirty but normally, and wasnt attached to the walbro

I change it, and after one hour of test, the problem is still here

Here you are a video on youtube of my problem

http://m.youtube.com/index?client=mv...?v=NdItnoTBGY4

thank you very much for your ideas


nicolas

[-nico-]

hi

no ideas?

here you are the good link for youtube, the first one didnt work

my dealer send me a new walbro fuel pump

he thinks its the origin of the problem

I operate saturday and Ill give you some news after tests

see you soon

nicolas from france


http://www.youtube.com/watch?v=NdItnoTBGY4

[-nico-]

my dealer send me a new wwalbro fuel pump

he thinks its the origin of the problem

I operate saturday and Ill give you some news after tests

see you soon

nicolas from france

[jasper]

It could be the fuel pump. Get a fuel pressure gauge and check your fuel pressure. It should be 39 - 40 psi. If the fuel lines or any component in the fuel line system is pulling air into the fuel system, it would prevent full fuel capability from being delivered to the engine even if the fuel pump is working correctly. There are a lot of possible areas to check, but I would start with checking the fuel pressure.

[-nico-]

hi

Ok thank you for your help

I receive the pump tomorrow

I try it and if the problem is still here, I will check as you say

my problem is my home is very far from the dealer location and we have to diagnostic with photos and videos.

when i change my fuel filter i take a photo of the walbro and it was rusty ,its why we think she is tired!

[jasper]

The engine behaves similar to water in the fuel. Carefully drain your fuel control cell into a glass jar to see if there is water in the bottom.

Another thought is an anti-siphon valve (also called a check-valve) on the fuel tank. I don’t know if your boat has one or not, but there are some that have reported that the valve would stick and not allow sufficient fuel through to the engine. The valve can be removed and cleaned or it can be replaced.

Good luck and let us know how it turns out.

[-nico-]

Hi guys

I change the fcc high pressure pump yesterday

I check the tank too and no syphon valve

I check all the fuel line and tight all

First test yesterday perfect, no rpm loss after 1,5 hour

But today...... The same problem appears after 1,3 hour

So no ideas!! Low pressure pump? Relays? Ecu? Or just the fuel but its not logic if its come when the
engine is hot....

[jasper]

This is a tough one. It runs well for 1.5 hours, and then the problems resurface after 1.3 hours. Is there any possibility the gas tank has debris in it that could be clogging the fuel pickup line?

[-nico-]

Its interessant

Yes when i open the tank where the gauge is located i find some debris

Maybe i have to go out all the fuel and clean the tank

My problems began after i put the full fuel capacity in the tank
And its was the first time. Before i put just 50 liters by 50.

Maybe it has increase the numbers of debris in the tank

[-nico-]

Its interessant

Yes when i open the tank where the gauge is located i find some debris

Maybe i have to go out all the fuel and clean the tank

My problems began after i put the full fuel capacity in the tank
And its was the first time. Before i put just 50 liters by 50.

Maybe it has increase the numbers of debris in the tank

[-nico-]

Hi
Yesterday i have checked all the fuel line, clean the tank totally and change the fuel
No results
I try with oil pressure sensor disconnect and same problem
I think it depends on engine temperature because its always at the same moment 1 hours at 2500 rpm
And yesterday for the test after 30 minutes at 3000

It seems an electronic security when engine is hot

Tomorrow i go to the french nautique dealer.... And yes we have just ONE nautique dealer here!!! You are very lucky in usa , you have more choice.

[jasper]

Please let us know what you find out.

[j2nh]

You might try removing the shroud, ours was red and said excalibur 330 on it if memory serves me correctly, we had a similar problem and after replacing just about everything we found that the shroud was trapping heat at the top of the motor and giving us inconsistent running. Easy and cheap to try.
Let us know.

[-nico-]

What is the shroud?
I dont find it....

[-nico-]

You want to say the red cover, just this part?