Challenger 2000, Starting problem.

[azirkhan]

Took my newly acquired model year 2001, Challenger 2000 (240EFI) out on the lake today for the first time. It started right up and ran strong for about 15 to 20 minutes with no problems. After a 5 min stop it did not want to start again! Twisting the ignition key resulted in the motor turning, several times it almost started but stalled right away!! I tried starting about 10 to 15 times with no luck.

I felt that if there was a way to "give it some gas" it would start, but the throttle is interlocked with the ignition (Throttle only moved after motor runs). To get over this problem I got my son to turn the ignition key and just as the motor sounded that it almost started I moved the gear and throttle lever forward, immediately it started!!!!

We were lucky, being several miles from the marina it would have been difficult to get a tow back given the distance not to mention that we were about to run aground! The ride back to the marina was fine, it ran strong but I lost confidence on the boat. Does any one know what could be the problem? does it need new spark plugs? Thanks for any advice.

 

[RFoster130]

I am sure one of the mercury gurus can help ya out. In the mean time, any idea on previous maintenance like fuel filters?

 

[azirkhan]

Previous history is a new motor in 2009, since then it has run aprox. 50hours. This season it has only been out once before on the lake. No maintenance since the new motor. I guess a new filter and spark plugs should help?

 

[RFoster130]

I would prolly change the fuel filters and plugs to start with, but let one of the mercury pros answer, they know these much better.

 

[onextremetahoe]

I had the same problem in the beginning of the season with my 2000. It would start and run great. But when you shut it off it would not start. It had to sit for atleast 30 minutes. I replaced the Head temp sensor. $35. The dealer told me it was probably bad and was reading the engine cold and was flooding it out. I have run it all season and have not had an issue.

Just my 2 cents.

 

[azirkhan]

Oneextremetahoe, thank you for your reply, very helpful, I have a few questions for you please:

1: When I turned the key the starter only engaged the flywheel for a second or so, in other words I could not cranking the motor continuously, is yours the same?

2: It appears that each cylinder banks has its own temperature sensor, meaning that two temp sensors are needed, is that correct?

Thanks again for your help.

 

[onextremetahoe]

Mine would try to start and turn over but it would stop cranking almost like the starter disengaged.

There are 2 sensors that look very similar, but they are difertent. The one on the passenger side is the head temp sensor I think the other is for water temp in the motor but I am not sure.

 

[azirkhan]

OK, bought a test meter to check the resistance of the Cylinder Head Temperature Sensor located on the Passenger side of the motor. Followed the procedure written in the Service Manual page 3C-5 by checking the resistance between the 2 wires colored Tan with Black stripe and it checked out OK. This seems to be a sensitive sensor with the resistance dropping just by holding it in you hand. Now I am a little confused as to what could be the problem, why the motor will not start when Hot.

 

[johnhibbs]

change temp sensor (plus get better gas mileage)

I ran the same test and it tested good so I didn't change it for a long time. I finally installed a new temp sensor (passenger side) and the problem was solved. I can list all of the other things I tried to fix it if you want. I think I get better gas mileage now too.

Another thing you can do to start the engine is to crank the steering wheel fully cw or cww and turn the key at the same time. Turning the wheel gives the engine more gas when you start. You can also removed the compartment bucket in front of the drivers side and pull on the throttle cable to give you more gas.

When you install the new temp sensor use some thermal conductive compound around the temp sensor. Radio Shack sell it.

 

[johnhibbs]

check exhaust hoses

As a new challenger 240EFI owner there is something else you need to know. The exhaust hoses can get old and come apart on the inside from the heat. They will start to get soft if you sqeeze them. What happens is you can't rev above 3000 rpm because of the blockage. Hard problem to solve.

This is a good site to get all of you questions answered for your SeaDoo 240EFI.

 

[azirkhan]

John, thanks for your advice, will have to try the "turning the wheel" approach next time I'm on the lake. I also checked the hoses and they are soft!! The max RPM I could achieve with 4 adults in the boat was 5700rpm and 47mph. Not sure if that is the max performance.

 

[johnhibbs]

max performance

47 mph is good. It must have been on calm water. I installed a Place Diverter for rough water. I wouldn't like this boat without it. It smooths out the ride on choppy water.

I have had to learn every part of this boat since I do my own repairs. I know that engine inside and out now. It's a weird hybrid SeaDoo/Mercury. My Mercury place won't work on it and the SeaDoo place doesn't know anything about the engine.

 

[azirkhan]

Yes it was in calm water, the previous owner said that it has a new motor 50 hours ago. Same here, I am going to do all the maintenance my self, nice to see there are other enthusiasts out there. By the way what is a Place Diverter?

 

[johnhibbs]

Place Diverter

http://www.placediverter.com/index.php?page=mercury

Or do a google search for: place diverter mercury

There are other brands out there but this one is for our boat. Basically it drives down the bow in choppy water. It also makes the boat get up to plan faster. I would highly recommend it. It can be installed in one weekend. It is adjustable with a toggle switch on the dash.

 

[johnhibbs]

Intake grate problem

One other thing you need to check. The original intake grate for the jet pump had a serious design flaw. The original grate looks like 5 or 6 black metal rods about 9" long and about 1" apart. These rods brake off and destroy the jet pump. Make sure you don't have the original grate on your boat. Replace it with the new steel design. The original grate destroyed a lot of jet pumps. When I checked mine it had the original and one of the rods was missing. Luckily it might have broken off when the engine was off.

 

[biffdotorg]

Is there a recommendation for a grate replacement? Is it just another stock grate that has been updated?

My 2002 x20 has what I think is the stock grate. I noticed it's trap-door design when I had to swim under to pull out some weeds. Nice to be able to get at the weeds, but an easy place to get a hand caught when doing so.

Are there any third-party grates that I should consider for performance reasons? Or just hit up the net or dealership for a stocker?

Thanks for the advice in advance.

 

[azirkhan]

Yea, it would be nice to get a recommendation on the replacement door. I checked mine, looks fine to me right now, however since it is made of cast iron therefore it could break if some thing hit it hard enough. Also looked at the impeller, the edges look blunt with lots of sign of impact with solid objects. Will have to sharpen the edge one of these days.

 

[johnhibbs]

HydroSurge grate

You should do a search on this web site for: HydroSurge
and read all the recommendations and see the photos of the
disasters caused by it.

Mercury makes the replacement grates. They have two types.
I bought the cheaper one. They are around $200 I think.

HydroSurge was what the original grates were called.

 

[johnhibbs]

HydroSurge grate replacements by Mercury

Replacement intake grates to get rid of the Hydrosurge:
These are Mercury part numbers, so your local Merc dealer should be able to order them for you. The part numbers are 852962T for a six tine fixed aluminum grate, and 854810T for an eleven tine stainless steel rock grate (should not be used in weedy areas).

 

[azirkhan]

OK, back to the starting issue when motor is warm, since the cylinder head temp sensor checked out OK, I now decided to checked the spark plugs, their condition looks good but the gap is 1.2mm instead of the 1.00mm recommended in the specifications. Could this be creating the starting issue when ward?

 

[johnhibbs]

temp sensor

Sorry for still harping on the temp sensor subject but do they ask you to test it over a temperature range? I don't remember removing mine when I tested it.

I just remember that mine tested "good" so I tried everything else that I could think of including replacing the starter motor. After everything else didn't work I read that other people had fixed the problem by replacing the temp sensor so I decided to give it a try. It was worth a $30 shot in the dark.

 

[johnhibbs]

temp sensor 240EFI Mercury

I kept the old temp sensor so I just checked it to see what it measures.
In a glass of ice water it reads about 1.4 k ohms across the two brown and black wires It also measures about the same across the brown/blue to black wires. The manuals says it should measure about 2.6 k ohms at 5 degrees C. At room temperaure it reads about 0.9 k ohms which is about where it should be. Running hot water over it the measurement was around 0.4 k ohms which is also about right.

Next I decided to open up the sensor with a dremel tool to see what's inside. There are two temp sensors inside. One goes to the brown/black wires and the other one goes to the brown/blue and black wires.

The most important thing I noticed was that the insulation on one brown/black wire and the black wire was melted off for about 1/8". This was on the inside of the sensor at about 1/4' from each sensor. Obviously the heat from the engine has melted the insulation on these wires on the inside of the sensor. Maybe when the engine gets hot enough these two wires make a connection.

The wires are potted in this small can like housing. I would think that the wires should have been centered in the middle of the can but mine had the wires running next to the edge of the housing. The wires were probably touching the metal housing on the inside of the sensor. When the engine gets hot the insulation on these two wires melted but the starting problem may not show up until the engine gets hot and the wires make contact. When the engine cools down maybe the wires don't make contact.

To check these sensors you probably need to heat them a lot hotter than 120-degrees F.

 

[azirkhan]

John, OK you convinced me! I bought a new sensor today and installed it, will be going out on the boat tomorrow, hope this was the problem, will let you know. Thanks.

 

[azirkhan]

OK, changed the sensor and took the boat out on Saturday. Before leaving home it started in the drive way with the garden hose. At the dock (cold motor) and in the water it did not want to start until I turned the wheel to one side thereby giving it some gas.
Throughout the time we were out on the water it started with no problem (with hot motor). Only once or twice it required some gas by turning the wheel to one side. The conclusion is that the sensor did indeed help with the starting problem. Now I have my confidence back.
Regarding fuel consumption, unfortunately the boat does not have an hour meter, I would guess we may have put in just over an hour of run time on the motor, most of the time running just over half throttle between 4 to 5 thousand RPM, it consumed quarter of a tank in that hour. Thanks to all of you that helped with your suggestions and comments.

 

[johnhibbs]

I'm glad to hear the temp sensor fixed the problem or at least it's a lot better now. I'm wondering what ocatane you use. I usually use 91 but that may not be necessary. You may get better gas mileage with higher octane and it may more than offset for the higher gas cost. Just a guess. It might be something to experiment with. I also replace the spark plugs every year.