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2004 optimax 150 SW Stalls suddenly

H

Hessel

New member
Hi,

I've read a lot of posts on stalling engines but didn't manage to find the right one. So I'm hoping that someone can help me out.

The motor starts and runs fine until we open up the throttle. At WOT it goes until approximately 3000/3500 RPMS and then dies, sometimes immediately, sometimes after a couple of seconds. When we keep it at 2600 RPMS the engine wil run for maybe 3, 4 minutes and then die. Under 2000 RPMS it won't die.

After dying it will fire right back up, no problems at all. Only if we go WOT directly after it died, it dies again (it won't even reach 2500 rpm). If we let it run at low RPMS for 20, 30 seconds it lasts a couple seconds more at WOT before dying again. (At the 3000/3500 mark)

No alarms sound and also the smart craft indicates nothing. Only when it dies that the fuel usage is 0.0

What we already did:
Cleaned the vst (was clean)
Tested the low and high pressure electrical fuel pump
Changed the sleeve on top of the high pressure fuel pump
Put on another tank (there is a spare connector, to switch to an extra portable tank)
Changed both water separating filters (the one on the vst and the one in the boat)

Thanks from Holland
 
Thank you, I will take a look.

I'm not sure if it's worth mentioning but the engine has ran 140 hours before we bought it. It has been sitting a lot I guess. Also when it dies, it's like switching the engine off.

The problem occurred for the first time at about 142 hours at WOT, we thought it was an incident with the kill switch so we continued the trip. After that it happened more often until the point where we are now. (151 hours)
 
I just reread your first post. Do you have to open the throttle to wide open to restart the engine? Or after you restart it, it will die if you go WOT?

If you do not have to open the throttle to restart, there is nothing wrong with the reeds in the compressor.

First thing to check with ransom stall, The condition of the belt driving the compressor/alt. If that belt slips because it is worn or the tensioner is loose the engine will stall as soon as the belt slips.
 
After we restart it, it will die when we go WOT.
Sometimes after 1 second, sometimes after about 4. Only if we're easy on the throttle. And go slowly till 3000 RPMS it wil hold 3 or 4 minutes.

I'll take a look at it. Thank you.
 
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So I've taken a look at it but wasn't able to reach a conclusion yet, because I wasn't able te let it run. I noticed that there was some space on the belt, I could easily press the two sides together, but I don't know if it's normal or not. Also on the cover there was a mixture of grease and tiny parts of rubber, and it has some damage by the air compressor filter ?


I will let it run on Saturday in order to see if the belt is floppy. I also attached two fotos, in case I'm missing something.

Thanks for the help.

WhatsApp Image 2019-06-18 at 20.58.22.jpgWhatsApp Image 2019-06-18 at 20.58.20.jpg
 
Hessel said:
So I've taken a look at it but wasn't able to reach a conclusion yet, because I wasn't able te let it run. I noticed that there was some space on the belt, I could easily press the two sides together, but I don't know if it's normal or not. Also on the cover there was a mixture of grease and tiny parts of rubber, and it has some damage by the air compressor filter ?


I will let it run on Saturday in order to see if the belt is floppy. I also attached two fotos, in case I'm missing something.

Thanks for the help.

View attachment 20739View attachment 20738
Click to expand...
What you can do is start the engine with the cover off and belt exposed. Wet your hand in a bucket of water and flick your wet finger towards the belt wetting it slightly, if the belt is too loose the engine will stall.

Pull the belt and look between the ribs, if you see the fiber cords of the belt, replace it.
 
Hi,

Today we testet the belt by wetting it, it made a tiny squeek but it didn't stall and the rpms were a steady 600. We also ran some injector cleaner but that also didn't help. It seems like the problem is getting worse, because it stops now even quickeer. After it died, we restarted it and tried to continue with half throttle, it died again in 2 seconds. But if we let it run for 10/15 seconds, it wil last maybe 5 seconds longer on half throttle.

Can there still be a problem with the fuel supply ?

Thanks.
 
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This winter we took the compressor apart, it turned out to be a bad gasket.
The compressor was leaking air in the water chamber and at high rpms it leaked to much so it caused the motor to stall.
 
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