Suzuki DF140 won’t rev over 3600

[Striker]

Hi all, my usually reliable Suzuki let me down today.

I’ve had a mare of a year so this was the first time I’ve used her in 12 months. Started fine cruised fine, but when opening up to plane she just won’t go over 3600 revs and climb out of the hole.

Is it likely that my fuel has gone stale - 200 ltr full tank, or do they suffer from other issues such as a faulty mass air flow sensor etc.?

[Pikey Dave]

Originally Posted by Striker

Hi all, my usually reliable Suzuki let me down today.

I’ve had a mare of a year so this was the first time I’ve used her in 12 months. Started fine cruised fine, but when opening up to plane she just won’t go over 3600 revs and climb out of the hole.

Is it likely that my fuel has gone stale - 200 ltr full tank, or do they suffer from other issues such as a faulty mass air flow sensor etc.?

Any faults on the gauges?

[Striker]

Originally Posted by Pikey Dave

Any faults on the gauges?

To be honest, I’m sat here now trying to find a user manual for the gauges to see how to access any codes.

It’s the round mf display ( I believe a Suzuki badged Lawrence) that uses the interface cable.

I’ve just read elsewhere that a low crank voltage can cause the interface to throw up an issue that causes a safe mode to be triggered. - it was a bit sluggish on cranking to be fair. But at least I can disconnect the interface and start without that to rule it out.

[Pikey Dave]

Originally Posted by Striker

To be honest, I’m sat here now trying to find a user manual for the gauges to see how to access any codes.



It’s the round mf display ( I believe a Suzuki badged Lawrence) that uses the interface cable.



I’ve just read elsewhere that a low crank voltage can cause the interface to throw up an issue that causes a safe mode to be triggered. - it was a bit sluggish on cranking to be fair. But at least I can disconnect the interface and start without that to rule it out.

Whereabouts in the country are you?

[FoxZulu]

No experience of Suzuki (apart from motorcycles) but in 50+ years of bikes, cars, and boats I've never had a problem with 'bad' fuel. If it is bad fuel I wouldn't expect it to run properly at any revs. In fact I would say it would be the opposite ie. running rough at low revs and improving as the revs rise. JMTPW and I'm sure someone with more experience than me will be along shortly to help

[Striker]

Originally Posted by Pikey Dave

Whereabouts in the country are you?

Hi Dave, the boat’s in a yard on the Menai Straights. Typically, we have rented a Holliday cottage for a week to try to get some use out of her, but aside from this she is also loosing air from the rear most section of tube (over 24 hours). But I’ve just popped back down to see if I can get a code from the instruments and found that that rear section of tube is leaking water!?! Is somehow open up a seam on the rubbing strip (where it’s been linked with the tube flat) and whilst underway managed to force water in. FFS boats hey… who would have them.

[neil.mccrirrick]

That may well be the reason it won’t rev

[Striker]

Originally Posted by neil.mccrirrick

That may well be the reason it won’t rev

That did cross my mind. The tube extends beyond the outboard which puts the weight well back trying to get on plane.

She was burning 25 ltrs per hour of fuel WOT at 3600 RPM so no issue with fuel delivery and it was like it just needed a push to get it over the bow wave.

Either way the tube repair is my new priority and I can worry about the motor once that’s fixed.

[Pikey Dave]

Have you checked the hull isn’t full of water?

[Striker]

Originally Posted by Pikey Dave

Have you checked the hull isn’t full of water?

Yes. I keep her on a trailer with the pug out and only put it in on the slipway as the angle gets that last bit out.

The tube was rather full of water as it has opened up on a seam where the rubbing strip is glued and the forward motion has forced water past the seam despite the tube remaining inflated.

It’s probably this additional weight that stopped her getting on plane.

[Orwell boy]

Originally Posted by Striker

Yes. I keep her on a trailer with the pug out and only put it in on the slipway as the angle gets that last bit out.

The tube was rather full of water as it has opened up on a seam where the rubbing strip is glued and the forward motion has forced water past the seam despite the tube remaining inflated.

It’s probably this additional weight that stopped her getting on plane.

Think PD is referring to the inboard plug ! the inner hull area fills thru the trunking in /out

[Striker]

Originally Posted by Orwell boy

Think PD is referring to the inboard plug ! the inner hull area fills thru the trunking in /out

It doesn’t have one, the interior of the hull is accessible from the rear bench seat which gives access to the batteries and shower pump etc. It’s a super yacht tender layout with moulded bench seats rather than jockey seats. And I can see the inner side of the hull which drains via the only plug in the transom. There are also two bilge pumps but I’ve never had enough water in there to trigger the float switch.