Loss of power 240hp EFI

[islandia-duane]

I've been reading the forum looking around for some of the same symptoms of a gradual slowdown while cruising. I think I found the culprit of my situation... a fuel hose leak!

I would be riding along and after 20/30 mins and then the power/MPH would drop and the engine sound changes.

I haven't ran the boat yet (It's January) to give you concrete results of a fixed issue but I have replaced the short hose connections that have become very elastic, maybe the wrong type of hose, not able to handle the chemicals in gas causing the leak

I don't know what these lines/hoses are called just wanted to post the images to help someone that may be still searching for solutions for a similar situation. They run vertically along the port and starboard sides

 

[Dr Honda]

The small hoses you are pointing at are part of the "Bleed System." (not fuel lines)

They are connected around the engine... mostly the reed block/manifold... and they are there to suck the oil and fuel that will puddle in the corners of the engine. (Where air velocities are low) That system is just light suction, so there aren't any clamps. BUT... if there are leaks... that's bad, since the engine is drawing air. (and can go lean)


Generally, a loss of power is a sign of over heating. Basically, as the pistons swell, and get tight... the engine looses power.

Normally, if you have a fuel issue... there will be sputtering (as it's running out)

Either way... since this is a 2-stroke... and over-temp, or a lean run is bad... I would start with a compression check. You are looking for 125 psi with the throttle open.

 

[islandia-duane]

Thanks Dr. I'll test drive it when I get a "warmer" day and post results of replacing those hoses. I'm hoping that fixes my issue. Thanks for the knowledge.

 

[islandia-duane]

Dr. Honda...So I took the boat out for run today, 60º in the Carolinas. After 5-10 Mins the RPM is constant but the MPH drops significantly. I throttle up to to see what happens... RPM goes up thrust doesn't increase. Any Suggestions anyone?

 

[Dr Honda]

Wellllll............

If you can run the RPM's up... but you don't get more thrust... then you have cavitation.

1) There could be damage in the pump
2) There could be something stuck in there. (doesn't take much)
3) There could be an air leak in the intake. (not very likely with the sportjets)


With that said... since your cooling water comes from the water pressure in the pump... that could be why you were potentially overheating. Also, on the Mercury seadoo boats. There is 2 buzzers in the helm. One is tied into the wires, and the other is mounted in the bottom of the helm. The "Mounted" one is the buzzer for the temp warning. It's normal for them to die after a while. So... I would test it, and replace it if you need to. FYI... I've replaced it on almost every seadoo project I've bought.

 

[islandia-duane]

Yep...there was a shredded piece os rope/string caught up on the shaft. Also had all those "bleed lines" replaced...they were so loose... Runs well again! May change the impella and wear ring next couple seasons. Rust on the wear ring

 

[xlonewolf1967]

what is the bleed system connected to ? I am installing a rebuilt 240 efi and have almost everything all set with the exception of the bleed system. bought the boat (2001 sea doo challenger 2000) with the motor already out and taken apart. I have the repair manual but it doesn't really show where the line connects to. I have this little stub of a line on the very top of the motor and no fitting even close to it to connect to. there is also a line on the back of the efi module that I cant seem to find a home for.

 

[islandia-duane]

I can't answer that. I was just poking around my engine looking for the drips...sorry