2002 challenger stalling in neutral

[crusty seadoo]

Hi guys, first post for me,

I have a new to me 02 challenger with the 240 merc. My problem has to do with the boat stalling only when in neutral and having difficulty starting after stalling.

These problems are most apparent when the boat is warm. The boat runs great when in forward and reverse. Idles fine and pulls smoothly up to full speed. When the boat is put into neutral, the rpms fall to between 600 and 800 and will usually stall within 10 seconds. The stall can be prevented simply by putting the boat into forward or reverse bringing the rpms up to 1000.

Now that it has stalled, it is difficult to start. The starter will sometimes spin and spin without the engine starting. Sometimes the starter will only engage for a second and the boat won't start. And when it does start, it stalls out very quickly. Seems to only start after not trying for a few minutes. Runs great in forward and reverse once started.

New fuel in the tank and a new battery recently installed (probably not fully charged though). Once again, everything else seems good when its moving in one of the directions.

I don't have the owners manual yet, and have googled for an answer and not found one yet.

Thanks in advance, Chris

 

[Coastiejoe]

In the marine world with traditional boats, the neutral safety switch does more than just prevent a boat from starting in gear. It actually eliminates spark while moving from gear to gear to prevent slamming into gear and what not. In the case of jet boats, there really isn't a forward and reverse in regards to the impeller.

I do not know if the neutral safety switch in our jet boats acts the same a traditional boats. If it does,,, then it could in fact be your issue.

If I get some time later today I will look at the wire schematic and I may be able to answer the question better based on what I find..

The fact that it ONLY HAPPENS when it is in neutral leads me to believe that the neutral safety switch is part of the issue.

Answer this for me, when you put the boat into clutch forward or clutch reverse, does the RPMs come up a bit from idle. Specifically, you go ONLY as far as needed to put it into gear and no further.

 

[crusty seadoo]

The boat idles at approx 1000 when put into forward or reverse, a great improvement from "neutral'. When i move the lever to forward or reverse, I do move the lever all the way forward or backward. I havn't noticed at what point in the lever movement that the rpms increase. I think I answered your question.

 

[Coastiejoe]

The boat idles at approx 1000 when put into forward or reverse, a great improvement from "neutral'. When i move the lever to forward or reverse, I do move the lever all the way forward or backward. I havn't noticed at what point in the lever movement that the rpms increase. I think I answered your question.

You did,,,
Based on your answer, it makes me think that the neutral safety switch does act like a traditional boat type switch.
Also, I am sure the neutral idle is adjustable. You stated 600 to 800 in your initial post. That is a substantial difference in the scheme of things. Again, I am not all knowing when it comes to the Seadoo jet boats, but I am thinking the idle is probably suppose to be 800-ish.

If it were me, I would look for an idle adjustment to at least turn it u a bit so that you can see what happens.

I'm thinking someone will chime in to help out with the specifics in regards to the idle numbers and what not..

 

[Coastiejoe]

I don't have an 02 manual. Only the 1998 and an 06.

Carbed models have an idle screw and Injected models have both a hard stop idle adjustment as well as an idle valve which has four-wires that run to it. This further makes me think it is controlled by the main brain based on things such as load and gear selection.

First things first is to ensure good base engine though. Good gas, good pugs, ect ect. At idle any issue will be amplified as compared to in gear where you can throttle through an issue.

If all is good, then I would check the hard stop idle adjustment and bump it up a bit based on your 600 to 800 range.

 

[crusty seadoo]

Thanks for the replies,

Plugs are new, new gas, and runs spotless everywhere but neutral. I intend on getting a service manual, until then, I don't know where that adjustment is or how to adjust it. Any pointers would be much appreciated.

 

[Coastiejoe]

It will be near the throttle control in regards to where it bolts to the engine.

With injection (in most cases), there is a HARD IDLE STOP as well as an idle adjustment. There is normally some sort of an electronic idle control as well such as a idle control solenoid for example.

 

[Dr Honda]

Hi Guys,

OK... Coastiejoe is on to something here... but I'm not sure he is leading you in the right direction. (completely) The Merc engine is a strange beast... and I'm not sure if he knows the ins, and outs of it. (if you do, sorry for the assumption) But, based on your last answer... I'm going to say that you only have experience with the newer Rotax engines.

Let me ask this....


When you put it into forward, or reverse... do the RPM's jump automatically, or is it that you can bring them up with the throttle lever?

If it's automatic... it could be the throttle guardian. It's a little black box that keeps the RPM's from getting over 2500 in Neutral or Reverse. But... if that box was failing... it would feel more like an ignition miss, rather than a low RPM. Regardless... It does strange things if they start to fail, and that box is known to fail, and cause issue. You can simply disconnect it. (I took mine out)


A few FYI's:

The Merc engine does not have an idle air control for high idle.

The Neutral switch is in the shiftier handle.


Now... before we can go any deeper with this... we need to know what engine you have. the 2002/2003 model years were split. So... is your engine cover round, or is it more of a rectangle shape?

 

[Coastiejoe]

Hi Guys,

OK... Coastiejoe is on to something here... but I'm not sure he is leading you in the right direction. (completely) The Merc engine is a strange beast... and I'm not sure if he knows the ins, and outs of it. (if you do, sorry for the assumption) But, based on your last answer... I'm going to say that you only have experience with the newer Rotax engines.

Let me ask this....

Dr. Honda..

I do NOT know the ins and outs of many of the seadoo engines.

I was in the Coast Guard for 23 years and I am certified in diesels, turbo rebuilds, blower rebuilds, small boat engines (aka out boards) and gas engines. Also, I was ASA certified for many years in the automotive field as well and have a very good understanding of the computer aspects of engines. How things can affect other things ect ect. Oxygen sensors, TPS, various pressure switches, injection, fuel pressures ect ect

So in this case, I felt certain there was some sort of an idle cut-off or idle control during shifting. That is why I asked him specifically what happens when he moved it to clutch idle...

I was just trying to help isolate the issue based on his imput. Yourself and a few others are definitely in the know when it comes to our skis and boats.

So no offense taken, not in the slightest.

My true goal was to have him answer the questions that needed to be asked so someone with more knowledge could step in and easily answer the question as to what is wrong.

 

[Dr Honda]

You were doing a great job of the trouble shooting... but I figured I should jump in to get to the specifics. I'm glad you didn't take offence.

The Merc 2.5L SportJet is basically the same as the 2.5L Merc outboard engine. In 2001-1/2 there was a major change in the control system, and the EFI. But... the newer engines didn't show up until late 2002 in the seadoo boats.

Normally when we see a merc that won't idle... the TPS or the Port side temp sensor has gone bad. Basically, it will run rich, and the idle drops. (Target idle is 1100 RPM in the water) But, it won't change from neutral to forward. That's why I was asking if it was instant, or if he was bringing the throttle up. (there is a mechanical lockout in neutral)

 

[crusty seadoo]

engine cover is round

 

[crusty seadoo]

I probably did bring the throttle up as I shifted out of neutral as it was on the verge of stalling. I noticed the forward reverse rpm at idle when I throttled down. It would seem like it would be some sort of neutral safety because it runs so good out of neutral. No smoke or any sort of hesitation.

It starts easily when cold or when it has not been ran for 5 minutes or more. But if I stall right after running, It takes a while to start.

It also had fuel filters replaced recently.

 

[Dr Honda]

OK... the round cover is the older engine. It's important to know that since the computer, and EFI system is TOTALLY different.

If it's the neutral switch problem... it would be a "On-off" kind of feel. So... as soon as you switched out of neutral... it would be an instant RPM jump. Also... like I was saying above... it would feel like an ignition miss.


From your description... I'm thinking your TPS is bad, or out of adjustment... or the temp sensor on the port side head is bad. Both of those parts are known to cause poor idle. But... let's hope the TPS hasn't gone bad. it's a $500 part.

 

[crusty seadoo]

Thank you for the replies. The fact that there is such a severe performance difference leads me to believe that it has something to do with the neutral switch. When in neutral, it doesn't just idle lower, it does miss and idle erratically down to the point it stalls.

One other weird thing I forgot to mention. When trying to start after stalling, I noticed that while trying put the boat in reverse, racing to get in "gear" so that it will run, the starter kicks in automatically. The key is that the boat is not running. As I move the shifter forward towards neutral, the starter engages when the lever is a couple of inches away from the indicated neutral position without me turning the key. The starter shuts down the first time the engine fires. It has started this way a few times.

Hopefully this makes sense, any thoughts?

Is there a way to inspect the shifter and neutral saftey for proper adjustment or operation.

 

[Dr Honda]

OK... if there is an erratic idle... then I'm going to say that the throttle guardian has gone bad.

It's a black box in behind the helm. It's not on any of the wiring diagrams... but it basically intercepts the Black/Blue (trying to remember the color off the top of my head) of the lanyard, and chops the ignition. If you unplug it... it should bypass the neutral switch.

 

[crusty seadoo]

Ok, I'll give it a try. Would it make sense that if the guardian is malfunctioning, the boat would be difficult to start?

 

[Dr Honda]

When it goes bad... all kinds of strange things happen. (hard starting, Poor idle, won't rev up, etc) It clips the ignition. But... since it's not needed... it can be removed before we look for any other issues.

Hard starting, and poor idle can be caused by other things... but you are saying it's very "On-off" and that's the only part of the electrical system that can react like that. This is assuming that when it's in forward... you can idle all day long without an issue... but as soon as you pull it back to neutral, the issue comes back.

 

[Coastiejoe]

CS, I didn't abandon you, just let the pros take over.

Still following the thread as a learning opportunity.

 

[crusty seadoo]

it will be a few weeks before I get the boat boat in the water. I'll update with results.

 

[crusty seadoo]

Did some more searching on the various message boards and found someone with a similar issue. His issue had to do with the starter engaging atoumatically (not turning the key) When the boat stalls and is boat back into neutral. He stated that once it automatically starts and he moves the shifter to forward or reverse, the starter disengages. That is one of the symptoms mine is having. He pinpointed it to the key switch. I suppose if the starter is engaged while in neutral, that it could be boggging down the engine while in neutral and causing it to stall.? I'm trying to find that part and figure out any diagnostics I can do on the key switch. Any idaes?

 

[crusty seadoo]

Just tried out the key switch and noticed that when I turn the key to start, the switch holds it in the start position and doesn't release it back without me having put it back manually. This would explain the automatic starting when putting the boat back int neutral. Holy crap there are a lot of wires attached to that thing.

 

[Coastiejoe]

Just tried out the key switch and noticed that when I turn the key to start, the switch holds it in the start position and doesn't release it back without me having put it back manually. This would explain the automatic starting when putting the boat back int neutral. Holy crap there are a lot of wires attached to that thing.

That would also make sense as to why the starter disengages when you put it into gear. Once in gear, the electrical loop is broken as you can not start the boat in gear... Once in neutral, electrical loop is back in place and the starter cranks up...