1998 suzuki DF70 mystery problem

[alexedit]

Hi all -
I have a 1998 suzuki DF70 with a mistery issue.
I was going at about 1/2 throttle when the motor just stopped.

When I crank it, the starter shoots with good power, but it releases the flywheel right away and the engine doesn't start.

The local tech told me it was the starter, but I disagree because the motor was running when the it just shut off.

When I crank it, the starter releases the flywheel right away, it doesn't even crank for 2 seconds before the starter releases.

any thought? Would really appreciate your help.

 

[tommarvin]

I agree with you, the motor didn't just shut off because of the starter.
The starter releases in less than 2 seconds might be starter.
Maybe change all on and off motor fuel filters.
I would remove and clean all battery cable terminals, a dirty corroded negative battery cable connection can cause a weak starter symptom.

 

[alexedit]

I just changed 2 gas filters about a month ago.

The battery poles are not corroded and have a very good connection.

The starter motor itself functions with goodfoece, but it just releases right away even though if I live the key on the crank position the starter still turns, but the starter clutch doesn't grabthe flywheel.

The thing is that...even if it was the starter, this does not explain why the motor shut off suddently.

Thabks for the input.

This is driving me nuts

 

[tommarvin]

I hear you, a mystery problem and you can't trust the boat enough to use it, during prime boating season., my fear also.
Your right there's two problems going on here, If a motor is running and it stops it seems like a no gas problem.
I would get a factory service manual, there are fuel filters on each injector if you have them.
We had this exact problem, we installed battery holders forgot to hookup the negative battery terminal from the motor, check your negative battery connection on your motor, A starter costs around 60 bucks, you install it yourself, make sure you have fuel delivery.
,wait a minute, check every inch of wire for bare or broken, grounded out,pull every wire that goes into a connector to check it, a random mystery problem, could be a wire or gas problem, the motor suddenly dies,wire grounds out, we had to pull our flywheel to test all our wires.

 

[alexedit]

I am getting to the bottom of it.
One thing is for sure... My local suzuki tech has no clue... Unfortunatelly.

Anyway, Today I put the battery on a charger and for a couple of hours and tried to turn it on and this time the starter did not release right away. I kept turning the engine until it turned on for a few seconds, this tells me it's a power issue.

Something that I forgat to mentiob was that the last few times that I took the boat out and was running it at full speed, I'd loose a good 20hp everytime I trimmed the motor.

Could it be that the battery is not charging? Or that the part of the motor that the part that charges the battery is bad? (I think it's called the magneto under the flywheel)

I did order a high pressure fuel pump and aill be changing that.

 

[tommarvin]

We bought two battery maintainers, one for each battery, we keep them hooked up 24-7-365 days, no more battery BS. Make sure the water is full in them.
We also bought a battery load tester at HF tools 22 bucks, you can have volts and a bad battery, a load test is the only way to know for sure.
We also bought the battery maintainers there, 22 bucks each.
I think not 100% sure about this,, the alternator on a outboard is called a stator it makes AC power, sends Ac power tor the regulator/rectifier that changes the power to DC power to power the 12 volt system on your boat.
I don't think you have a magneto your motor is newer than our 1988 Force 125hp we don't have a magneto, we have a stator under our flywheel.
You could be proactive and remove the flywheel and look for brown or burned marks on stator, check every inch of wire while your in there, for bare, broken, disconnected wires, pull all wires hard that go into connectors.

 

[99yam40]

you can test voltages to see if the battery is being charged properly

 

[alexedit]

No Title

Hey everyone - I am happy to report that the mystery has been solved. It was the VST Tank. I changed the high pressure fuel pump that is inside of the vst tank and that was not it. So turned out to be the connector inside of the VST tank.

BUT now I have another issue. I a couple of hoses that I can't find where to hook up

 

[Tao]

No Title

Hi,
Looks like water hoses (that, seeing the white traces, have been leaking a bit)
Here are some pictures from the DF70 service manual for 2003 model you might find useful (especially the 2nd one).
Does not look that different from your engine.
Hope this helps

 

[alexedit]

Thank you tao -
I found a guy with the same motor down the street from me and I hooked everything up and it's great.
I even hooked it up to a computer and saw all the motor life - it only has 398 hours

BUT NOW THERE IS ANOTHER ISSUE!!!

the VST tank has a hose on the top that foes to the manifold inlet. This hose is leaking gas when I stay at low rpm for a while.

what could this be?

 

[Tao]

Not sure which hose you're talking about.
From what I see on the 2003 manual and my 2008 engine, no hose containing fuel or air make a direct link between the VST and the intake manifold.
Maybe you should post a picture of both ends of the hose so we can figure what it is...