Sea doo Challenger 2000 240 EFI gen 1 bogging down.

[rsatina2002]

Hello Sea doo jet boat experts,

We went to Lake Perris Ca today and I have a very bad experience on my 2002 Sea Doo Challenger 2000, i'm using a bimini top and pulling a 3 man water tube, running at 12 mph at 4,500 rpm with my 2 sons on the tube and my dad is the one driving. My 4 year old decided to go back to the boat and my dad turn of the engine and shit happens, it won't start at all, I check battery connections and I did really had a tight knot on batteries and it has a good starter sound and engine trying to start but died. The boat has been running for 2 hours already but stop for 30 mins in the dock area to prepare for water tubing with kids. Finally after 30 mins, engine back to good starts sound and runs again but it is frustrating to have the boat won't start hot and easily starts cold. I have my boat last 2 weeks ago has rope in the impeller shaft with pictures i posted and now this happens. Is that normal for a 240 EFI engine to not to start when hot and when cold easily starts, any experience boaters out there, please give me advice what to check on my engine. My spark plugs was change last August 2018, new fuel filter, new oil, fresh fuel 89 grade, change the fuel pump in the vapor separator with none OEM brand. My Sea doo is always idling at 1,500-1,750 rpm. Another experience later in PM, with my kids in the boat with water tube vacant, running at 42 mph with bimini top at 6,500 rpm and suddenly engine feels like bogging down and decrease it speed suddenly and about to stall and decrease the rpm to 4,000 and continue to run at 18 mph with engine still has episode of bogging down. Please help me fix this jet boat we love it with out family. Thank you in advance Dr. Honda, I know you have answer about this but I appreciates your input everybody. Thank you again.

 

[Dr Honda]

It sounds like you have a few things going on. But first... you can't blame the boat for you sucking the rope into the pump. Even if you had an I/O or outboard... you can pull a rope into a prop, and end your day.

When everything is right... these engines start up almost instantly hot or cold. So... the hard starting when hot can be a few things. The first thing is... did you run your bilge fan before trying to start it? These engines need good fresh air to get going. If you did... then the next thing would be to check your port side temp sender. When it goes bad, it over fuels the engine. After that... there are a few more things to check, but it gets more involved.


As far as the loss in speed... that's never good. Did you continue to try to run it at a high throttle setting... or did you pull it back to idle, and just limp back to the dock? Regardless, because of both problems... you need to do a compression check. Let me know what you get on all 6 cyl's.

 

[rsatina2002]

Thank you Dr. Honda, I'll check the compression for all of the them. I forgot to mention to you, I did change the port temp sensor last august even though I don't know if it is bad or not. I didn't turn on the fan at all after it stops, I didn't know that I need to turn on the fan for few minutes, but I did open the engine compartment for like 15 mins and finally it did start after. So I don't know what is wrong now why is it not starting hot. When I go to 42 mph for 6500 rpm full throttle and I didn't stay for long and return the throttle back to slower position due to water tube is flying in the air already. Thanks for your reply Dr. Honda, i'll check the compression and give you an update, i'll also post my spark plugs pictures if it is really flooding with fuel inside. Thank you again.

 

[rsatina2002]

Hello Dr Honda, here is the findings of my compression check, bought a compression testest in Autozone and findings are Cyl 1- 120 psi, cyl 3- 118 psi, cyl 5- 120 psi , cyl 2- 110 psi, cyl 4,6 no reading due to gauge broke. All good sparks on in line testers but sparks plugs are most black in color except cyl 5.. posting pictures.... port side temp sensor at 1.22k ohms at cold 50 deg temp, 80 deg temp at .88 k ohms, TPS findings at idle .29 mV at WOT 7.40 V transitioning smoothly. I can’t find now whats the problem of this hard hot start issues and rich smoky smelly engine at 1,500-1,750 idle rpm. Im posting videos for the engine and sparks plugs for youe reference please help me what to correct this issue of 240 EFI engine...

 

[rsatina2002]

Here is the video of idling at 1,500 rpm let me know if it does sound rough engine.

 

[Dr Honda]

Out of the water... there's no load, and you really can't tell anything. (sorry)

Yep... all plugs look good other than #4. I'm guessing that the injector may be leaking, and that will lead to the hard starting. But we still need to get a compression number on the other Cyl's.

 

[Tim75]

Who hasn't picked up a rope on the shaft? Those that have and those that will.
2 for me.

A thought on this problem--
Could the stroke/metering link be on the wrong side of center? That is -- full oil at idle and minimal oil at WOT. Backwards. Causing overheat and bogging. If still running 42 @6500, may there is no damage yet.

Was the comp. test done at WOT?

What is the idle rpm IN THE WATER?

 

[rsatina2002]

Who hasn't picked up a rope on the shaft? Those that have and those that will.
2 for me.

A thought on this problem--
Could the stroke/metering link be on the wrong side of center? That is -- full oil at idle and minimal oil at WOT. Backwards. Causing overheat and bogging. If still running 42 @6500, may there is no damage yet.

Was the comp. test done at WOT?

What is the idle rpm IN THE WATER?

Hey Tim, compression test done on warm up engine in the garage.... Idle rpm in the water still at 1,500-1,750 rpm.

 

[Tim75]

But you did not say if test was done at Wide Open Throttle.

Your numbers are low--- trying to figure out why.

Idle is high for being in the water. Take a close look at the link to the oil pump. Is it correct? Is it holding the throttle open slightly?

 

[rsatina2002]

Hi Tim75 and Dr. Honda, to finished my compression test, all compression test was done on cold engine outside the water, and it is on idle and i don't know how to test the compression on WOT. I noticed my port side cylinder compression test was the same at 100 PSI on cylinder 2, 4, and 6. Also I found out, air temperature sensor is not functioning and when I tested it it is open circuit, so no resistance at all and im ordering a new one at boats.net. So I tested the port side temp sensor both my old and new sensor, I notice both of them are working I'm using a digital meter and exposing to heating gun and ice and recording the ohms and coincides with the book ohms table with temp and resistance for the sensor. For your other questions Tim, oil pump link seems align to normal recommendation from the book. My idle in open garage and in the water is the same at 1,500 rpm to 1,750 rpm. Let me know what other parts I need to check. Maybe this hard hot starting problem will be better as soon as air temperature sensor arrives. I really didn't know that air temperature sensor will go bad also and as the manual says it might the cause of my rich fuel mixture during idling. Thanks for your help everyone. I really want this 240 EFI Mercury engine to last long and will be maintain by my own hands since in California, no more marine shop will repair Mercury engines due to parts are rare and needs to order it online. I will do my best to let this engine keep on running and my kids and me to enjoy the boat. Thank you for your help everyone.