DF140 (johnson) Tachometer setting on BRP Gauge

[Camw308]

Hi

I am wondering if anyone can shed some light on the correct dip switch setting for a 2004 Johnson DF140 with a BRP gauge? after the first time on the water i am almost 100% sure its not reading correctly.

The engine really wants to sit above 5200 rpm (displayed) and will make power past 6200rpm (displayed) with alot more in it, Im spinning a 13x19" stainless 4 blade, 785kg hull, 23 degree deadrise.

At 4500 rpm im only doing 19 knots, Factory brochure performance figures state 4000rpm = 22knots.

Dip switch is currently on position 5 (5 pulses per revolution) I am suspecting it should be on 6.

Thanks in advance.

[Moonlighter]

I dont know about the tacho setting. You should really have a Suzuki 4 stroke tacho on there because it has the warning lights on it that flash codes to tell you what any problems might be. Pretty important.

But aside from that, the DF140 should be running a 14” dia prop. All engines in the 90-140 series do. I run a 14 x 20” on my DF115 (2010) on a 18ft 18deg V hull. So with a 13 x 19 you may well be significantly under-propped and thus over revving.

Also, be aware that the early DF140’s such as yours ran a different gear ratio to later models, so depending on what brochure you are looking at, they may not reflect how your engine might perform. And unless the exact same boat as yours is the one tested by the factory, with the same year engine, same ratios and same weight, then what they get in test conditions vs what you get will be two different things.

[Camw308]

Thanks Moonlighter, i will have a look into it, the BRP gauges are compatible with the DF140's sold under License by Johnson, all Warning lights, Oil pressure/Temp are operational.

I do have the original 14 x 19" 3 blade with is so ill put that back on and see how it goes.

The Brochure is actually from on water test of this particular hull/motor combo in 2004.

Cheers

[nicolouris]

Best prop for that engine is 14x19. Due to the large gear ratio we have to use the maximum diameter of prop. Also check 14x18 4 blade power tech.

I have johnson 140 2006 model.