Troubleshooting 2000 Challenger 2000 with 240 mercury

[seidel1981]

Ok here is the story i recently purchased a 2000 sea doo challenger before buying i checked the compression on all cylinders and the boat started right away every time all the time no hessitation or missfires so i took it home, took it to the water and to my surprice boat shuts down every time i give it throttle so I took it home did some research ended up changing the exhaust Hoses since they felt really soft also change the Inline fuel Filter, Fuel water separator filter, syphon valve, and spark plugs, took it to the water and Problem is still there, I need some help guys what should be my next step now ? :banghead:

 

[gerrychuck]

I am certainly no expert, but this does sound kind of like the problem I had last fall with a weak battery. The fuel injection system in the 240 is very sensitive to voltage drops; as you advance the throttles the draw from the injectors increases; if that pulls the voltage below the critical level, the motor bogs or quits. Seems a bit weird if there is still enough power to start the boat, though, but it's all I got

 

[seidel1981]

Thanks but I did have the battery checked and the power good

 

[WAJetboating]

Hook it up to a hose and start the engine on the trailer (follow the procedure in the manual - water on first, then engine on, then engine off, and finally water off). Let it idle for a few seconds, then carefully advance the throttle so that the RPM's do not exceed ~2500 and don't stay up there for very long.

This is a quick, rough test of the fuel system. On the trailer the engine has almost no load on it at all, so very little fuel is required to bring up the RPM's. In the water, a jetdrive is ALWAYS moving water... and bringing up the RPM's requires more fuel. If the engine has trouble in the water but not on the trailer, I'd look really hard at the fuel delivery system.

Report back!

 

[WAJetboating]

Also, when you say "boat shuts down every time i give it throttle" can you be a little more descriptive? Does it slow down and die? Cut off abruptly? Cough and sputter? Is there some RPM threshold at which this occurs? Does the engine restart instantly and idle fine?

More info = more help from us.

 

[seidel1981]

Ok the engine sputers and dies once I get off idle, it cranks right up after it dies and it idles perfecly fine again

 

[canadianwhiskey]

Try changing the plugs. I had something similar happen last season to me. I changed the plugs and was working fine after that.

 

[seidel1981]

To Wajetboating I will be performing that test this afternoon I'll report back tonite Thanks

 

[WAJetboating]

To Wajetboating I will be performing that test this afternoon I'll report back tonite Thanks

Pay close attention to what the RPM's are when it sputters. Is it just barely off idle, or up a little ways? There are certain RPM thresholds that mean different things.

 

[seidel1981]

In the water it sputters at about 2000 rpms

 

[WAJetboating]

In the water it sputters at about 2000 rpms

If it also sputters on the trailer at the same RPM's. I may have a one-wire fix for you that will take about five seconds to test and cost nothing to fix permanently. The fact that it actually DIES makes me a bit uncertain, but otherwise all the evidence is pointing in a certain direction.

Report back....

 

[WAJetboating]

Also, once it starts sputtering can you instantly drop the throttle and keep the engine running, or does it stall every time?

 

[seidel1981]

Every time I tried That only managed to stay on 1 time out of about a good 5 tries

 

[seidel1981]

I'm on the way to the boat now I'll be doing the test on the trailer in about an hour and I'll report back the results

 

[seidel1981]

No Sputter, hesitations and no turning off on the trailer.

 

[WAJetboating]

Well, there goes THAT theory. It was electrical, by the way.

This sounds like a fuel problem. It takes far less fuel flow to rev the engine on the trailer because it's under essentially no load. That works fine. It takes far more fuel flow to rev the engine in the water because the impeller is moving water all the time and the engine is loaded. That doesn't work. The big difference is in the amount of fuel required; and when the engine has a load but is starved for fuel, it does what engines do when they're starved for fuel - it sputters and stops.

You said compression is good. The engine starts quickly, which doesn't require much fuel flow but does require lots of other things to be working properly. Everything points to fuel flow IMO.

Time to think about the fuel system. Did the boat sit for a long time before you bought it? Could fuel have sat in the fuel system, deteriorated over time, and gummed things up? That could restrict fuel flow in a number of places: Needle/Seat, VST, HPFP filter, pressure regulator filter, injectors, HP fuel lines....

Grab the manual (available on this site, I'm told) and run some of the fuel system tests. They're not difficult, require only basic tools, and will reveal a LOT.

Also, when you said you had "checked the battery", did you actually put a digital voltmeter on it while the engine was running? A battery under no load will usually read plenty of voltage. What matters is what it does under load. That earlier response that mentioned the battery was correct - and you should confirm proper voltage while the engine is running with a DVM. (Available at Harbor Freight for under $5.)

There's several things for you to check. Report back!

 

[seidel1981]

Took the boat to a mercury mechanic and the fuel pressure regulator was bad replaced with a new one went to the water and the problem is still there :/ I don't know what to do now I'm stuck

 

[ddeem]

I agree that this sounds like fuel... My regulator had a cracked vacuum hose that caused hesitation problems. You may want to check your vacuum lines. If the float in the evap tank is messed up that would cause problem as well... Also, how about the primary fuel pump? There are two fuel pumps. One primary and one in the evap tank...

Dave

 

[seidel1981]

Now seem more like an electrical problem we checked the fuel system already now when I have the throttle down boats idles perfect when I give it a bit throttle it tries to shut down half way down the middle of the throttle but if I just hit it the boat planes great if I then bring the throttle to the middle it tries and dies again but if I bring the throttle all the way down and don't pause at the middle it stays at idle just fine seems to me the problem is just when the trottle lever is only in the middle.

 

[ddeem]

I completely rebuilt my engine (thread under full rebuild with pics) and I can say that it sounds like it could be the trigger unit? Not that I am a professional, but it seems like this part woud kick in at half throttle... Under the flywheel there is a timing advance setup... You know what, I believe thay have trouble with these trigger wires shorting out on something from rubbing. As you get to half throttle, the trigger assembly moves to advance the timing. If the wires are bad they could be rubbing during this and killing the ignition... I would pull the flywheel and check the wires and trigger assembly. With the flywheel off, you could move the throttle and watch the trigger assembly move to the advance position.

Good luck... My trigger assembly was replaced on my boat before I purchased it so I know they do go bad. Maybe you could search for this in the threads..

Dave

 

[seidel1981]

I saw that the Triger assembly is about 95.00 dollars how hard is it to change ?

 

[ddeem]

Pretty easy... You need a large socket for the flywheel nut (not sure of the size) and them a puller for the flywheel. This is the challenge as I purchased a puller / eye hook assembly to lift the motor out of the boat. Think you can find them on ebay. Look under mercury flywheel puller ... Once the flywheel is off, you remove the stator with allen screws and then the trigger. Has a long wire that is fed through and a linkage that is connected to the throttle lever on the motor. Would be very easy if you have the puller.

Dave

 

[seidel1981]

Thanks a lot for the help I'll give this a try.

 

[seidel1981]

Finally problem solved after all this time I decided to take the boat back to my mechanic and I had him check my tps sensor the readings on it were off at half throttle so we replaced for a new one now the boat runs like a champ just in time for summer thanks for all the advise guys

 

[Chal2K]

If it also sputters on the trailer at the same RPM's. I may have a one-wire fix for you that will take about five seconds to test and cost nothing to fix permanently. The fact that it actually DIES makes me a bit uncertain, but otherwise all the evidence is pointing in a certain direction.

Report back....

WAJetboating: i'm having a similar issue and want to follow your train of thought on the one-wire fix ... where were you going with that?