F115 Fuel Flow

[Fishnmike]

I just picked up a new to me Duckworth Navigator with a F115 TXR with a manufacture date of 10/2006. My consol has limited, analog gauges (Tach, Spedo, volt meter and fuel gauge) Since fuel tank gauges are next to useless I would like to install a fuel flow gauge.

Looking at the various options it appears that a Lowrance LMF-400 with the Yamaha harness to connect to the ECM would probably be the most cost effective way to go. From my research it appears that inline flow meters don't work well with this engine due to some back feed issues from the high and low pressure fuel pumps. Am I on the right track with this? Any other cost effective ideas short of installing a full Yamaha gauge package?

Thanks,
Mike

[rodbolt17]

fuel flow data from the ECM is NOT physically measured flow.
its calculated based on injector on time and 45 PSI on the fuel rail.
its actually close.

nothing to do with pumps.

[Fishnmike]

Hey Rodbolt, thanks for the reply. Used to read your posts on the other site before the mod issues developed over there. Yeah I understand that fuel flow from the ECM is not measured flow but as you say it is very close. What I am after is, is the LMF-400 gauge connected to the ECM a worth while way to get at that number?

There are inline fuel meters that actually measure flow but I have read online from both the flow meter manufactures and from users that they don't work with with mid range Yamahas.

[boscoe99]

An inline fuel flow meter works just hunky dory with an F115. Works well with any other Yamaha for that matter.

You are probably reading about Yamaha outboards with electric lift pumps that cycle on and off at low speeds.

Instantaneous fuel flow is intermittent if and when the fuel pump cycles. Not a problem as who cares about instantaneous fuel flow below 1200 RPM anyway. Total fuel consumed is always accurate.

What happens when injectors become clogged and fuel does not flow as readily through them? Is the calculated methodology of determining fuel flow going to be accurate?

I need to find out more about the other website from which Mr. Bolt was banned. Anyone care to tell?

[Fishnmike]

Good point Bosco about plugged injectors as well as immediate burn rate is not important while idleing as long as it totalizes the consumption. Do you have a unit you reccomend?

Thanks,
Mike

[rodbolt17]

I would either rerig it with command link or use the Yamaha FMM setup.
unless you already have the electronics that are NMEA 2000 compliant.

the 2 gauge command link square kit will give a ton of engine data and if the tri-ducer is used 3 more paremeters.

[Fishnmike]

My Humminbird is NEMA compliant although not plug and play. Looks like I have to get a NEMA blackbox (as eth nmea2k) from Humminbird and then setup a NEMA backbone in my boat. I would also need a harness from my Yamaha to the NEMA correct?

[boscoe99]

What is the model of the Hummingbird?

Most NMEA 2000 chart plotters just need an NMEA 2000 network interfaced to it, to which engine data can be provided via a Lowrance 0120-37 cable.

[rodbolt17]

yes, I think Boscoe has posted how to tap into the white 4 pin connector on engines rigged without command link.

I cant remember if flow data is avalible this way.

[Fishnmike]

I have a Humminbird 859 DI. My understanding from talking with Humminbird Tech Dept is that I would have to get the Humminbird blackbox I listed earlier that would then allow me to plug into a NEMA backbone.

I pulled the cowling tonite and looked for the plug that the Lowerance interface cable would plug into. Could only find one plug similar and it only had two wires going to it. I do have a full wire harness going to the helm that the tach data is delivered by. The rest of the wires are pigtailed off.

Thanks for the help guys, its really appreciated.

[rodbolt17]

the plug your looking for has a white connector 4 pin with a blue and a white wire.
as your current setup is not command link it will be capped off.
or should be.

[Fishnmike]

Ok thanks Rodbolt, that is the plug I found. I figured there would have been more than two wires going into it so I didn't think that was it.

[99yam40]

I need to find out more about the other website from which Mr. Bolt was banned. Anyone care to tell?

You and I post there also, you can do a search to find his posts.

It was a short term thing, but Rod came here and said he would not go back

[boscoe99]

You and I post there also, you can do a search to find his posts.

It was a short term thing, but Rod came here and said he would not go back

Got it. Thanks.

I have a photo of Mr. Bolt accepting his Master Mechanics pedigree. I wonder if he would mind me posting it?

[rodbolt17]

if you post the pic , can you photo shop it and make me young again .
I don't mind , Yamaha used to post it on the Yamaha marine master tech home page.