701 Dies when Throttled, Dies at Low Speed, Won't Restart, Then Restarts

[E350]

Today while riding the FX1, after riding for about two hours, the engine would start, but die as soon as I accelerated.

I tightened the battery cables, checked that there was about a 1/2 full tank of gas.

Tried to putt upstream to the launch ramp but even at low speed it eventually died and wouldn't restart.

On her Super Jet my wife towed me back to the ramp.

The ski wouldn't start to drive it up onto the trailer.

But, the ski started no problem on the trailer when we got home.

I know how to diagnose crank no start conditions.

But sometimes this engine starts.

I don't like intermittent problems. So, I usually wait until things break completely before I start my trouble shooting.

However, I would like to get this going asap.

Any suggestions?

 

[VXSXH20]

The coil could be acting up when heat soaked. It cools down by the time you get home and restarts. Perform some resistance tests on your coil with a DVOM (meter) I don’t recall the OHM specs off the top of my head. You’d have to check it again when it’s warm and acting up. Unfortunately you’d have to take the Ebox out to do all this. Perhaps heat it with a hair drier to simulate the under hood temps.

 

[Quinc]

Sounds like CDI. But also check compression.

 

[te4250]

I had same exact symptoms and it was the coil, common for coils to heat up, short through the insulation, cool back down and work again. I have had very similar symptoms and it was the cdi twice, stator once, and start stop switch once, so could be anything but I would guess coil first lol.

 

[E350]

Ok guys. My riding today is riding on you.

I have a known good coil.
I have a known good MSD Enhancer 650/701.

Which do I swap in?
I will only swap in one, because I want to isolate the problem.

What say you?

 

[te4250]

Have a multimeter to test coil resistance?

 

[E350]

Hmmm...

Well I have never had the E-Box on the FX-1 open before.

A couple of things:

1. It only had three screws keeping the E-Box it together (so I will have to scavenge skis from the spare E-Box for now and place an order with Jet Maniac).

2. There was one red wire which was disconnected (see 1st photo, what does it do? -- see 2d photo where I connected it. But its disconnection didn't prevent the engine from starting just now. And reconnecting it didn't prevent the engine from starting either.

3. Water has previously been in the E-Box but it is not wet now.

4. The coil from the 1994 SN SJ says 61L-00 (and was rewired by Jet Ski Solutions 2 years ago). The coil from the 1995 FX1 says 62L-00. Any way to tell if the FX1's coil is OEM?

I am going to clean it up and swap in either or both coil and/or MSD and see how it goes.

 

[Quinc]

You should have a local fastenal or bolt place that you can put in socket cap bolts instead of screws and pick them up today. I believe that goes to your start switch. Also try unhooking your blk/wht wires off the start/stop switch and see if it has spark after that. (you will not be able to stop the ski with these unplugged)

 

[TOBY]

Have you checked the filter inside the carb/carbs

 

[E350]

Have you checked the filter inside the carb/carbs

No, I forget is it accessed through the pump side?

 

[E350]

Yup, I see the carb filter in the manual.
It is under the pump on the outboard side of the carburetor.
I will pull it after dinner and see if it is clogged.

 

[E350]

@TOBY, quick! Which one is the before photo and which one is the after?





FYI, for guys and gals who are somewhat new to skis like me, the OEM Yamaha Service Manual for your skis model and year is cheap and invaluable. Buy it.

To be somewhat scientific, I think I will complete my order with JetManiac for the screws (and I will add one of these filters so I can keep a spare around) and clean up the E-Box and reassemble everything as it was (but with more screws from the scavenged ski) and see how it runs. So, although I would like to put a MSD Enhancer in it as well as Jet Maniac's Yamasaki high spark coil, I will hold off on the MSD and coil until I see how it runs tomorrow.

Thanks for everything. You guys are the best.

 

[mikidymac]

I would also get a new inline filter/water separator since all that crap in the carb filter came from somewhere else.

 

[E350]

I put in a new OEM inline fuel filter when I bought the ski in September of last year and now holding up to the Sun, it is still clean.

I see some crap in the bottom of the fuel tank which I will suck out with the Topsider pump (which looks like a blue version of the old Eagle gas can with a hand pump screwed on to the fuel inlet).

The Water Separator I just drained based on your suggestion @mikidymac.

In a little bit I will put the E-Box back together with the original parts.

Last night I cleaned the metal part of the box with vinegar and then with Dremmel with a wire wheel as well as I could and then spray painted it black and it is still curing in the Sun.

 

[Quinc]

The inside of the fuel line deteriorates and fills the internal filter up with these little hair looking things.

 

[E350]

Thanks @Quinc I did not know that.

I replaced the original fuel line, deleted the fuel selector lines and replaced the choke butterfly with a fuel primer when I bought the ski.

I replaced all the oem fuel line with orange Tygon. So, those little hairs should not reoccur.

I replace the Tygon about every three years on our skis because it becomes brittle and cloudy.

Hopefully this afternoon I will find out whether or not the fuel filter was my only issue.

 

[TOBY]

It will run like money now the OE in-line filter will brake down over time and clog that filter with what will look like pocket lent. Sometimes it’s the small stuff but I bet the wires on your coil are broken and need to be replaced

 

[Vumad]

Buy a superjet.

 

[E350]

Ding, ding, ding.

We have a winner!

And he is ...

TOBY !!!

When we meet which will likely eventually happen since you are just up the road in Chico, I will buy you the alcoholic or nonalcoholic beverage of your choice.

Honorable mention: VXSXH2O, Quinc, Te2450, JC-Superjet, and mickidymac. All reasonable diagnoses and, fingers crossed, hopefully disproved. Although we had some wind chop and rolls on the river today, I was able to do enough short wide open runs to mimic what I put the ski through on Tuesday and no symptoms whatsoever.

Vumad we do have a '94 SN Super Jet. I replaced the CDI when it failed with a MSD, I had new spark plug wires installed on the Ignition Coil by Jet Ski Solutions, I replaced a burned out lighting coil with a new stator with three new coils from Jet Ski Solutions.

So the CDI and the Ignition Coil were very reasonable guesses. But they both did fine today. So they live to ski another day and it was a fuel starvation problem caused by the little filter/strainer under the fuel pump in the carb. Thanks Toby!

Vumad why are you talking about Super Jets anyway? You have an X2 as an avatar. I hope you will give me advice when I put the 650 back into and otherwise rebuild my wife's X2.

Thanks for all your help guys.

 

[Jetfiend]

Just get a Kawasaki...


I've been waiting to say this for years!