Best 4 stroke for my 5.4 f Signature

[scottar]

Good result. Happy days ahead.

[banksmister]

Any updates desertislander, good or bad.

I have the same rig and have kicked round the idea of a 140 zuk.

[desertislander]

Any updates desertislander, good or bad.

I have the same rig and have kicked round the idea of a 140 zuk.

Hi Banksmister,
What can I say, I am very happy, it's all everyone said it would be and more and runs on the smell of an oily rag, I am doing at least twice the mpg. It is a very smooth and quiet with no more chokeing two stroke smells, it's a dream ride, mind you I have only just about run it in, but so far so good.
Oh, and another thing, I did go with the SS prop

[banksmister]

Thanks Di..............

[The Black Unicorn]

Hi Banksmister,
What can I say, I am very happy, it's all everyone said it would be and more and runs on the smell of an oily rag, I am doing at least twice the mpg. It is a very smooth and quiet with no more chokeing two stroke smells, it's a dream ride, mind you I have only just about run it in, but so far so good.
Oh, and another thing, I did go with the SS prop

You won't go wrong dealing with Jon at Bayside Suzuki. Great fella that knows his stuff.

[gloverpcg]

Hi Guys
Just found your discussion on the 540F with the Suz140. I have the same rig with a solas 13 7/8 x 21 SS prop. Top speed is ok 60kph but holeshot not so good. What was the final decision as to prop choice?
Would appreciate any advise.
Cheers
gloverpcg

[desertislander]

Hi Glover, I have had little boating in the last few months, had to get my hip replaced consequently motor is still being run in. I take her in for a 20 hour service in a couple of weeks so should be able to wind her up a bit once thats done. I did go with the stainles prop but have no idea on size, will ask service guys when I see them. Sorry I can't be more helpful
Cheers mate

[swof63]

Hi Guys
Just found your discussion on the 540F with the Suz140. I have the same rig with a solas 13 7/8 x 21 SS prop. Top speed is ok 60kph but holeshot not so good. What was the final decision as to prop choice?
Would appreciate any advise.
Cheers
gloverpcg

hi Glover.

ive got the 543 with 140 and the Suzuki 14 x 20 SS prop. Does 65kph bending the tach needle ( about 6400 I think ) and hole shot is pretty good. Way better than the original 21 aluminium it came with, maxed at 60kph and holeshot was bad. Still does 0.8l/nautical mile with the 20 so I'm happy.

Cheers craig.

[Moonlighter]

Yep, the Suzuki 14 x 20 stainless prop is a good one. Got it on my Surtees 5.5 with Suzuki DF115.

Gloverpcg, what is your max rpm with current prop?

[gloverpcg]

Hi Moonlighter
Max rpm is around 6100-6200.
Forgot to mention also have an hydrofoil from ozpropellers. Does'nt seem to improve the holeshot.
Cheers

[Moonlighter]

Ok the 14x20 Suzuki Ss should be good then. Foil wont improve hole shot, just helps keep the nose down.

[gloverpcg]

Ok the 14x20 Suzuki Ss should be good then. Foil wont improve hole shot, just helps keep the nose down.

Thanks
Ozpropellers do a 14x20 SS American import for $650 (should be just as good as the genuine) so I will add it to my wishlist.
Cheers

[Moonlighter]

Be aware that the US OEM Suzuki props and the Australian ones are apparently slightly different. Plus, every different brand prop, even though it is the same dia and pitch, can have different blade shapes/sizes so will perform differently. So that would apply to the American import prop you're referring to.

Generally the conclusion I've seen many people reach is that the OEM Suzuki props have an edge over the aftermarket brands in terms of their suitability on Suzuki motors.

[MikeC90]

Interesting read... I have recently picked up a 1998 540F, still running the original Merc 115 2 stroke. The motor has only just clicked over 200 hours and seems to be running well - though I've just dropped off the gearbox for seal replacement. So far I've only used the boat with a minimum of 4 adults + little fella + gear on board but performance and economy seem very acceptable once the motor is warm. According to the GPS she's doing 62km/h WOT with all the weight on board plus an extended canopy (bit of aero drag there). On the last trip I did around 65km and used a little under 30 litres (dip stick measurement), so over 2km/L. Granted 20-30% of that distance was trundling along just above idle while negotiating shallow water, but I must say I was pleasantly surprised by that consumption. Current prop is a Laser2 SS 13.25 x 20, with no vent plugs installed.

My only real complaints with the setup are lack of flexibility at low speeds and of course the 2-stroke oil smell at idle with a following breeze. The 2+2 arrangement combined with the vented prop make it really awkward at lower speeds. From idle, adding throttle does nothing for a while, then a bit more throttle and the extra 2 cylinders fire up (seems to be at 2,000rpm for my motor) and then you're all of a sudden doing 3-3,500 rpm and getting on plane. So pretty much idle or on plane, nothing in-between. It also seems to drop back off the plane if the revs dip below 3,500rpm and is quite hard to 'catch' when it does so (needs a big dose of throttle ASAP). I suspect this is due to the vented prop though, as soon as it starts dropping off plane and the water speed drops, the prop cavitates more and a vicious cycle ensues...

So with this in mind I've been researching the current motor options in the power/weight class. My builders plate also states 135hp max but hopefully I might also be able to get Signature to condone a 140hp install like the OP. Based on what others have quoted for the hull in this thread, it seems as though the main gains for a new motor would be a more linear and quiet delivery, with performance and consumption in the same realm

[blacklab]

Hi Mike, I have experience with the larger 125 2+2 2 stroke engine.
There pretty bullet proof, they have an un balanced crank so the engine is limited, 5300 revs from memory. 2000 revs is when all cylinders should kick in. I found it a pig when trawling, getting it in the swell between that ideal trawling speed proved a pain in the arse. Mine was converted to full time 4 cylinders, which fixed that issue, but anything over 3500-4000 revs you the fuel use was out of control. I suspect that she is probably a tad under powered for the hull, mine was a 5.4 with the 125, which would then mean it's working a bit harder to keep it up on the plain and probably drops off at certain points too. I had a luv hate relationship with mine.
The new 115 4 stroke merc is the same cubed motor as the 140, and a tad less weight, so that's one to consider. The newish Yam 130, is just a tricked up version of the 115 block, a 1.8 litre block, so that could be an option as well.........
I have some time up my sleeve before I pull the trigger on a new 4 stroke, so still kinda deciding......

Col