Df90a stalls when prop looses bite

[Ausmat]

Hi guys,

I have twin df90a on a shark cat and the port motor stalls when the prop looses bite on the water, it has happened several times in the past couple of months.
Last time it happened I was doing 22knts at 4000 Rpm went over a bit of swell and the prop lost bite and the engine revved high and stalled. It restarted and ran fine for the rest of the day.
It had the iac replaced 6months ago is the only issue I've had with the motor.

Has anyone herd of this problem.

[Moonlighter]

Hi Mat. Fellow Aussie, I assume?

No, cant say I have.

When the engine loses bite, like when youre airborne, naturally it over-revs.

Now when our Suzukis over-rev, they automatically drop back to idle and you have to pull them back into neutral and wait a second or two before shifting back into gear and accelerating again. Ive had this happen a couple of times in aerated water when crossing a bar.

Is that similar to what yours is doing? If so you might need to drive a little more conservatively and keep that Sharkcat's hulls in the water!

What does your dealer say?

[Ausmat]

Hi moonlighter,

I'm from the **** Coast, I spoke to Keith (dealer) who said his never herd of it before. And advised I might need to re learn the iac valve. I'm not sure of that process.
When it looses bite it actually stalls and I have to restart it bit scary going out Currumbin bar.
Cheers Matt.

[Moonlighter]

Keith (at Motorsport Marine) is very good on the Suzukis. If he is the Keith youre referring to. Have another chat with him about the IAC idea - he will say what needs to be done.

Do you get any buzzers or warning lights? Has Keith connected it up to the Suzuki SDs computer since this happened? It will show fault codes if they are there.

Or you could talk to my local guy - Jon Eadie at Bayside Suzuki Marine at Cleveland. He is closer to you than Keith anyway.

Take that Currumbin Bar easy! It can be nasty, not to mention playing dodgems with surfboards. So back it off a bit - i know you Sharcat guys like to fly, but better to go steady when crossing those bars!

[Ausmat]

Moonlighter,
I've been going out Currumbin for years, had a few hairy moments lol.
I am referring to Keith at motor sport (great bloke ), it stalls even if I hit white water ,I take it very easy going out the bar as I don't want the motor to stall.
Not sure if and warning lights flash when it stalls but I hear a single beep.
I have a guy coming tomorrow to put his sds unit on it,
Does the after market sds units give the same details as a Suzuki dealers unit?
It shuts down a couple of seconds after it looses bite on the water if it was a cooling issue would it record an error ?

Regards Matt

[Moonlighter]

SDS aftermarket should be same as factory. Expect it will show all codes.

I wonder you have a VST float level issue...... might be starving momentarily as it gets on an angle. Really, too many possibilities.

Tell Keith everything you can. If it is easily repeatable can you get a mate to video it when it happens, that would help Keith figure it out. It will most likely be something simple.

[redlowrey]

When it over rev's do you pull the throttle back to neutral, or does it stall without touching anything, and I assume both engines over rev but only the port motor stalls.

[Ausmat]

Hi redLowry,
It stalls at high revs pretty match as soon as it starts revving.
Regards Matt

[noelm007]

I also have 90s on a Sharkcat, and have never had that issue ever, except for a recent problem, and a prop problem, they have been faultless, and very powerful for a 90.