M2 - 240 starts out of water but doesn’t in water.

[Natrillius]

I’m looking for some help in troubleshooting an issue I encountered today. I recently purchased a very clean 2001 Challenger 2000. It runs very smooth out of the water on the hose hookup, today I was taking her on her maiden voyage and to my surprise she would start in the water. I pulled the boat out and she started within a minute. After repeated no starts in the water I started out of the water Then had someone back my truck in while manipulating the throttle cable attached to the steering wheel. It ran with the additional throttle applied but would stall shortly after I stopped with the extra tension on the cable. Has anyone experienced this before.? It really put a damper on the family day in the lake. Hoping for some guidance. Thank you

 

[Natrillius]

I’m looking for some help in troubleshooting an issue I encountered today. I recently purchased a very clean 2001 Challenger 2000. It runs very smooth out of the water on the hose hookup, today I was taking her on her maiden voyage and to my surprise she would start in the water. I pulled the boat out and she started within a minute. After repeated no starts in the water I started out of the water Then had someone back my truck in while manipulating the throttle cable attached to the steering wheel. It ran with the additional throttle applied but would stall shortly after I stopped with the extra tension on the cable. Has anyone experienced this before.? It really put a damper on the family day in the lake. Hoping for some guidance. Thank you

Additionally, I notice two wires that look as if they should be connected to something or each other, can anyone provide insight ?

 

[Natrillius]

Additionally, I notice two wires that look as if they should be connected to something or each other, can anyone provide insight ? View attachment 37595View attachment 37596

The wires in question are the brown with white stripe and green with white stripe center frame of the first photo, second photo is zoomed out to show location on left hand aside of engine.

 

[Dr Honda]

The wires are normal. Those are for extra Mercury gauges than Seadoo didn't use.

As far as the starting situation... it sounds like.....

1) You aren't firing all 6 cyls. (Check spark on all 6)

2) The engine is warn out, and has low compression. (do a compression check)

3) If the above is OK... then make sure the idle isn't low. But... since it looks like you have a Gen1 240EFI, that's probably set properly.

 

[Natrillius]

The wires are normal. Those are for extra Mercury gauges than Seadoo didn't use.

As far as the starting situation... it sounds like.....

1) You aren't firing all 6 cyls. (Check spark on all 6)

2) The engine is warn out, and has low compression. (do a compression check)

3) If the above is OK... then make sure the idle isn't low. But... since it looks like you have a Gen1 240EFI, that's probably set properly.

Good Morning Dr. Honda,
Thank you for your quick response and troubleshooting tips. I performed both spark and compression testing this morning. All 6 cylinders have a strong ignition spark which I was hoping WASN’T the case. The compression test however revealed a worn engine only achieving 70-78 PSI cold. [emoji30] So I guess that means it’s time for a rebuild. In your opinion is it worth rebuilding or should I cut my losses? Would the life expectancy of a rebuild be similar to new if maintained properly and not abused ?

Thanks again for your help and advice.

 

[Ashaman074]

I have the same boat. FWIW my first time out I was concerned as while it started on land right away; but in the water it would start, then die right after. It did this like 7- 8 times, after which it stayed running and was fine. Ran great the rest of the day, and every start thereafter was immediate. Next time out cold, did the same thing again.

I now start it on land right on the dock before launching, idle for 10 seconds, then launch. I have no issues if I do it this way. That said, those compression readings are definitely low - are you confident the gauge is accurate? I tested mine at the beginning of the year, and all were close to 120; which I think is pretty normal.

Are you mechanically inclined? If your numbers are correct, I would definitely teardown with the intent of rebuilding personally.

 

[Dr Honda]

Good Morning Dr. Honda,
Thank you for your quick response and troubleshooting tips. I performed both spark and compression testing this morning. All 6 cylinders have a strong ignition spark which I was hoping WASN’T the case. The compression test however revealed a worn engine only achieving 70-78 PSI cold. [emoji30] So I guess that means it’s time for a rebuild. In your opinion is it worth rebuilding or should I cut my losses? Would the life expectancy of a rebuild be similar to new if maintained properly and not abused ?

Thanks again for your help and advice.

Well.... that could be OK. My first response would say... YES, rebuild. But, with the gauge you used... is it known to be good? Over the last few years, there have been a bunch of import gauges, and they read low. The reason is... they put the valve in the gauge body to save a few $$$. The little Schrader valve core should be in the tip of the adaptors. If it isn't... then the volume of the adaptor and hose is added to the combustion chamber.


But... if the gauge is good, that would 100% be why it will start with no load. So... at that point I would start with simply popping the heads off. If nothing is melted, then it's an easy job. You may be able to just get away with a quick hone, and new rings. (and a gasket set) Yes... there's some time involved but you could bring it back to life for a few hundred $$.

 

[Sportster-2001-951C-Stock]

Definitely need to confirm the compression gauge is correct before making further decisions.

Also, sometimes the evinrude/johnson engine tuner or quicksilver power tune in a can will free-up the sticky goop that deposits in the ring lands and interferes with ring seal. I recommend this on a periodic basis, once every year or two.

 

[Natrillius]

Thank you all for your help and advice, today is the first day off that I’ve had in a while and I intend on doing some additional investigating. The Gauge I used was brand new but it was of inexpensive variety from harbor freight which could be playing a factor in the readings. The gauge itself has a 20 inch connection hose which I’ve read could also cause variability in readings. None the less, I’m going to see if a neighbor or local parts store has a reputable brand available. I also want to double check Dr. Honda’s idle speed point. Obviously idle out of water is different than under load, does anyone have a baseline of what idle speed should be at out of water and in Water? I faintly remember the guy who sold it to me mentioned he had played with the idle recently but didn’t provide more detail than that. I’m at the point where if a rebuild is needed I’m certainly going to have it done, the boat is beautiful minus this, I simply want to make sure it truly needs it before i start taking it apart.

 

[Dr Honda]

With the second gauge... just look for that little "Tire" valve in the tip of the adaptor. If it's there... it should be fine.

Unlike the little 2cyl Rotax engines... the loaded, and unloaded speed isn't a big change. I idle around 1000 rpm in the water (little less on hot days) and about 1100~1200 out of the water.