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2001 seadoo challenger -mercury 240 Wont Pass 4500 rpms, i need HELP

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Lukes4tow

Lukes4tow

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The boat ran fine for a while , and then i shut it off . After two hours parked it didnt want to start . I took it to the shop and they diagnose a Bad stator,. They put a new one original from mercury and it did start fine. But the tech. tested it in the water and it doesnt go pass 4500 rpms. i told him it was running fine before but the only thing was it didnt want to start. Need help .
 
If it's running OK other than the low RPM's... that's generally a sign that a couple cyl's aren't firing. AND... since he was under the flywheel... he was where the triggers were.


I would simply start with some new spark plugs... but get an in-line spark tester, and verify that you have fire on all the wires.


FYI... I'll move this to the Merc section.
 
i just replaced the spark plugs and i did the spark test with the inline spark tester . All 6 cylinders are ok. very good spark. Whats next?
 
compression tested all cyls. strong ,good.. I would like more info. on how to set the timming . Im a going to pull off the flywheel to look at the new stator and also to check that trigger.
 
What's... "Compression tested strong"?? Give us numbers. Since you want help... we need the info.


Also, when you checked for spark... did you verify there was still spark at the upper RPM's?

Have you looked at the throttle links, and verified that the throttle is actually opening all the way?

Last question... when it gets up to 4500 rpm... does it just not go any higher? Or does it feel like it starts to stutter?
 
it does not stutter. Yes the throttle is opening all the way. How do i checK the spark at the upper rpms? does the boat have to be in the water or with the water hose????
 
Yes... generally you need to be in the water, so there is a load on the engine. To check it... use the in-line tester, and have someone watch it. Make sure the spark isn't dropping out.



But, if the engine is running smooth up to 4500 rpm... and then just not going any higher... then you may need to get your hands on an engine analyzer, to really watch the ignition, or to see if there are any miss-fires. There are some generic versions for automotive use... but if you can get a Mercy DDT... it will tell you more.


Last thing... if you slowly run the throttle up to 4500 RPM... is that at "Full Throttle"? or does it get there early... and then leave the last part of the throttle doing nothing? (Did that make sense?)

Just for my knowledge... can you post a picture or two of your engine?? There were a few versions over the years.
 
did you try opening up the throttle manually I know at one time my cable was lose and full throttle wasint opening up all the way try opening it up by hand and see if that get you more.
 
I did put the boat in the water and it ran fine for 10 mins. Around 6000 rpms Full throttle and then it dropped to 4500 rpms by itself, And also it did it a couple of times. But now it wont go pass 4500. The throttle goes slowley from idle to full throttle ok but wont go more than 4500 rpm. I also did the spark test fom low rpms to high rpms and it seems like the two top cyls. Left and right are dropping spark and sometimes its stuttering.Those two cyls are totally different spark , comes and goes. I do have videos of each cyl. Spark test. Can i show you the videos some how? Let me know . Thanks
 
Yes the throttle is oppening all the way . And it opens slowley from idle to full throttle , wont pass 4500 rpm. Thanks.
 
OK... the 2 top plugs dropping out would make sense on the 4500 RPM's. It will feel perfect... just wont' rev up.


By any chance... is #3 dropping out also?


If not... I would look over the wires, and see if something is cut. (like a bad ground)

If #3 is also dropping out... you have a bad CDI on 4,5, or 6.
 
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Im sorry, but whats the firing order.? I dont know whos 1 ,2,3, ... ??? Cyl. Location?
 
The only ones that are dropping are cyl.#1 & #2 and it drops from idle to full throtle.And it starts mis-ing at the point that it sounds like Rev limiter
 
The firing order... looking at the front (from the transom) of the engine is:

1 2
3 4
5 6


Now.... if it happens to be numbers, 1 and 4... then you have a bad trigger.

If it's 1,2, and 3... then you have a bad diode in 4, 5 or 6. (they balance each other, for charging)

If it's truly only 1 and 2... then you either have a bad wire some where... or both coils/CDI's are going bad. (They don't have a common part that would kill those 2, without causing a problem on another coil)


Somewhere above... I asked for a picture of your engine. I kind of need it, to know exactly what engine we are dealing with. It has changed over the years. Right now, I'm assuming it's an early 240 EFI. Also, I know some people have come here saying they have one engine... and when we get a pic, it's something else. FYI... there are basically 5 Merc engines that Seadoo used, and the ignition is different on all of them.

210 carb
240 EFI early
240 EFI late
200 DFi (optimax)
250 DFi (optimax)
 
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Yep.

From the tag, it's an early 240 EFI. But can you post a bigger, overall pic of the engine?

But, if you go from my post above... you can start to check the parts.

If we assume the trigger, and ballast units are OK... I would simply move the 2 CDI/coils that are having an issue, to another spot. (Swap them with a good coil) that way, you can see if the problem moves with the coil, or if it stays with cyl.

If it moves.... it's the coil.

If it stays... it wires.
 
REALLY hoping to hear back Lukes4tow.
Have exact same max 4500 rpm issue with my 2 generation 240EFI in my 02 utopia 185.

2nd issue was the port side cylinder head temp sensor which made it a huge dog even getting to 4500.

Changed that and it pops out of the hole now but no 4501 - 6250 rpm. That's a lie, it ran up to 6000 once but then refused to do it a second or every time after that.

Mike.
 
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6MISFITZ said:
REALLY hoping to hear back Lukes4tow.
Have exact same max 4500 rpm issue with my 2 generation 240EFI in my 02 utopia 185.

2nd issue was the port side cylinder head temp sensor which made it a huge dog even getting to 4500.

Changed that and it pops out of the hole now but no 4501 - 6250 rpm. That's a lie, it ran up to 6000 once but then refused to do it a second or every time after that.

Mike.
Click to expand...


Please start your own post if you would like help... but I would start with checking the compression. 125~135 psi is what you are looking for.
 
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