DF140 been sitting.

[aquamort]

Hi there.

Ive just joined due to now owning a Suzuki...and having some troubles. I bought a Dec 2007 DF140 a few years ago however it sat in the shed not being used due to a major rebuild of my boat (which took longer then expected!).

Ive read a lot of threads on these engines and started having concerns! It seems that the engine holder on mine has been replaced already as it doesnt have "That" plug. Ive had the bottom leg off and it looks clean enough. Had hose of thermostat off at both ends and looks clean so hopefully i dont have a corrosion problem!

It took a bit to get it going. I ended up draining the fuel from the rail. I added a bottle of injector clean and have had it idling. I dont think it is idling as good as it should though? Its not real bad but thought it would be smoother.

Ive got the fuel in the oil problem though.(I changed the oil before running it and have only had it idling with muffs on)

Ive read it will be either the low pressure pump or the VST. Ill start with the low pressure pump due to it being easy. Does the diaphragm split and let fuel in?

I personally would bet that it is a stuck needle and seat in the VST. I will attack it all in the next week. Is there anything i should be particularly looking for at all?

Cheers

[Harper]

You're off to a good start. I, too, would check the low pressure fuel pump first, just because it's easiest to pull. Yes, the diaphragm is the culprit if that is the source. Fuel will enter the crankcase via a ruptured diaphragm.

You seem to understand the situation if the VST is the cause.....stuck float needle or crud on the needle seat causing the needle not to seat properly, leading to an overflow of the fuel....again to the crankcase.

So good luck on your "adventure." Keep us posted on your progress.

[aquamort]

Ok ive pulled apart the low pressure pump and all looks fine. I was hoping so much to see a torn diaphragm i nearly put a hole in it myself.

So looks like its off with the manifold etc... have a wedding this weekend so will be in the next week till i tackle that job.

[aquamort]

Went to a boat show today and spoke with a tech guy from Suzuki. He gave me a quick tip to test the VST.

I pulled off the vapour line and pumped my primer and sure enough fuel pissed out the vapour hose. At least I know im not wasting my time pulling the intake manifold off now.

[aquamort]

Ok so i snuck out to the shed and pulled the manifold off when i was meant to be doing something else, as far as the wife was concerned anyway.

The VST is full of crap. The needle was jammed closed. So hopefully just a good clean, reassemble and away we go!?

[Harper]

I'll keep my fingers crossed........

[aquamort]

Cleaned it all up and put it back together and the fuel in oil problem is solved. Still have not had it out on the water yet so have to wait to see how it goes under load.

[aquamort]

Checked it again and fuel is coming out vapour hose again...should of just replaced the needle and seat when i had it apart the first time but at $50!! Im now also worried about the regulator that sits in the VST. I'd hate to go for my first run to find its stuffed too but at $250 i think ill be taking that chance.

BOAT = Bring Out Another Thousand !!!

[aquamort]

Well i had the outboard and boat for their big water tests. The motor ran great! Quiet and responsive. Running a 14 x 17 prop on at the moment, boat is a 17ft glass boat, and think i will go to at least a 19inch pitch...maybe even a 21? as it get to WOT in no time at all.

[aquamort]

Whats a good cruising RPM for DF140? mine is doing 4100 at 20knots. RPMs seem high to me? That with a moderately loaded boat which at times would carry a bit more weight.

Regards

[Harper2]

It depends......

....what's your rpm at WOT? That's the main criterion that you would use for prop selection. If it's within your specified max RPM range at WOT with your normal load, then the prop is correct. At that point, you basically live with whatever cruise figures you get.

[Moonlighter]

They do tend to rev higher than traditional 2 strokes. But don't worry, that's what they like!

My DF115, same block as your 140, cruises at similar revs and speed as you have stated on my 18ft plate alloy cuddy cab.

These engines need to be propped to reach 6100-6200 rpm at wot. I run a 14x20 Suzuki stainless prop and it gets me nicely into that range, top out at 65km/hr.

He she is sitting on 5200rpm at about 52km/hr:

[aquamort]

Thanks guys. My WOT is the rev limiter lol. Yeah i had a 150hp 2 stroke and it only revved at 3000rpm for the same speed. I would of thought a 4 stroke would revved lower? So when cruising at 20 knots at about 4100rpm i was a bit worried and didnt want to push it any more.

I have a 14 x 17 on it now. Think at least 19 or maybe a 21? Wish there was somewhere you could just do a prop swap or something.

[Moonlighter]

I see you are a fellow Aussie. Where are you located?

What hull have you got it on?

The 4 strokes do rev higher. It's a torque/gearing thing. A17 is far too small. I would have thought at least a 19" if you stay alloy, or a 14x20 stainless same as I am running.

Talk to Steve Evans at Solas props on the Sunshine Coast. They will not only be able to advise you on the best prop, but if the one they send you ends up not being the best, they will swap it until you are happy.

They are a good mob, and are probably the most knowledgeable people in Australia re matching engines, props and boats.

They deliver to your door throughout Australia.

[aquamort]

Hey Moonlighter. Yep I'm in Brisbane too. I'm running it on a Haines 17R.

Thanks for the advice mate. Solas seem to be the go. Ill chase them up when i have a spare few hundred.