NewMoon

NavMan F2100 - Digital Fuel Flow Gauge with Single Engine Transducer. Will this setup work on the above motor? I need a round gauge unit.

Tyee 2

Should work on any outboard, as long as it does'nt have a fuel return line
to the tank.

V20Ralph

I don't think the F150 flows enough of fuel at low rpms .

First Light

Yes, it will work fine, but Ralph is correct. Most four strokes burn so little fuel at low rpms that they will not activate a fuel flow meter. I have tested some four strokes that will not show fuel flow below 1500 rpms.

aimless

I have an F115 Yamaha and it reads 0 below 1500. A little annoying but also a beautiful thing

jtburf

But how does the total burned and remaining workout, with the low rpm issue?...John

gf

Don, why not splurge for the Yamaha fuel management gauge?

NewMoon

Hmmm that's interesting that this gauge will not read below lets say 1500 rpms on the 4-strokes.

GF- The Yamaha gauge is about $250.00 more- ouch! I wonder if it also would suffer the same as the Navman in not reading below 1500 rpms.

First Light

NewMoon: Yes it does.

John: That is a potential error problem. Don't know if anyone has checked to see how accurate the totalizer/total fuel burned function is for a four stroke that spends a lot of time trolling at rpms below 1500. I've also seen Yamaha HPDI's with this same anomoly, although they will usually read fuel flow at rpms lower than the four strokes.

aimless

Mine with the F115 is always inacurate on the total fuel used. The only time it's right is at cruise. At slow rpm.s when it's showing 0 fuel consumption it's not recording for total either. It's pretty useless except for cruise gph. Maybe the floscan is better, I don't know.

NewMoon

Thanks for the info guys. Given that these things can not read usage at low rpms on the 4-strokes, it will probably not benefit me as most of my fishing time is spent slow trolling or idle drifting.

Reel Pursuit

I have an F225 and was seriously considering buying this unit because of its cost and ease of installation.
If what you guys say is correct about low RPM readings then the Total Fuel Used and Fuel Remaining function will be of no use. Seems like the only benefit to having this unit is to measure the GPH at cruise to find the most optimal cruise speed. This would be great for offshore trips but I'd have to rely on the existing Yammi guages to know what fuel remains in the tank.

jtburf

I see it like this if you go 1/3's rule your still safe ... 1/3 out 1/3 back in 1/3 in reserve ....
My main concern is being a 100 miles from the nearest gas pump and not knowing how
much I have !!!!! ...John

gf

My new McKee came with the Yamaha fuel management gauge already installed, I probably would not have ordered it.



I'll report back this summer with my useage findings on the 150 HPDI.

cgrand

according to navman tech support the fuel flow reading at low troll on four-strokes is going to likely be inaccurate

i got the 3100 anyway, because what i really needed was the fuel economy feature at cruise, and it's also a back-up speedo & voltage gauge (plus i had a 3 3/8" hole to fill!)

i don't do any trolling so i'm either cruising or drifting, no in between

abacodan

We just repowered from Saltwater Series 200 OX 66's to a pair of '03 F225's.
Thought the mechanic had messed up the reconnect on the Yamaha Fuel Management guage, since the fuel consumption was continually attempting to settle at idle. Checked the one on a nearby boat with the same engines and the same result. The unit appears to get its wits about it just above 1,000 RPM, which on our Contender is just above a dead idle. Haven't burned enough fuel through it to determine how much inaccuracy this causes on overall fuel burn. It never had this problem with the old 200's, but I would never go back, based on this small anomaly. I'll bet a fix will be out before long. Awesome performance from these engines!!!

Reel Pursuit

Abacodan-
some previous posters stated that the Navman wouldn't work on 4 strokes that have a fuel return line to the tank. I assume your F225 doesn't have this? Just curious because I plan on adding the Navman to my F225 also. ;?

kevdog

I'm using the Navman on a 115 Johnsuki and my trolling RPMs are definitely over 1500. Idle is around 625 or so and my typical trolling speed is around 7 - 8 mph.

If you're spending a lot of time trolling at idle I wouldn't think you would have to worry about your overall burn rate being that far off. When you factor in the other benefits of the unit, like finding the sweet spot when you're at cruise, the unit is really useful.

Kevdog

abacodan

I don't know of any outboards that have fuel return lines. This applies to diesels, which are addressed by specific fuel return hookups on all the fuel computers. My partner had a flowscan system added to his Bertram 54, it just requires more fittings. The whole point of this discussion is that the fuel computers apparently lose some sensitivity at low fuel flow rates. I personally think the paddle wheels in the line need to be upgraded with greater sensitivity to accomodate the awesomely? low fuel flow. I'll be able to let you know soon how inaccurate the system is with the F225's. Haven't had to visit the fuel pump yet. It was always within one or two tenths of a gallon with the old 200 OX 66's.

NewMoon

Well hopefully somebody will figure it out soon and offer a unit capable of calculating even idle fuel consumption. For now I guess the ole top it off prior to leaving the dock then top it off when you return to figure your consumption is the best way to go.