fuel consumption ranger 21

[Wim]

We are the proud owners of WINELIGHT our 21 RANGER tug . Would like to field a question to other TUGNUTS .

Our engine is a 3 cylinder 30 hp Yanmar. At 3200 rpm all is well. If we increase the speed to 3500 rpm the unused
fuel is not returned to the tank but spewed overboard via the exhaust system. Not a good thing. If any member
of the esteemed TUGNUTONIAN SOCIETY has experienced this problem, and rectified it, we would be forever
thankful if you could share this information with us.

Wim

 

[rt11002003]

Wim,

I find it interesting that you can attain 3500 rpm under load. If I remember correctly, Yanmar says that engine should be propped to attain 3600 rpm, plus 200 rpm to allow for additional weight that usually accumulates on a vessel. Sounds like you're closer than I am. I've been moaning for months about 3250 rpm being my max. Most of the other R-21 EC owners have reported similar max rpm under load. I've discussed it with Jeff and Andrew, both of whom think it is normal and offered to provide another prop if I want to pursue the matter. 🙂

Now to the crux of your issue. How do you know the return fuel is going out the exhaust? Are you checking the return line at the tank, or are you looking at the exhaust? My tug emits a nice steady stream of white exhaust when running full out. But, it is just steam, no smell of diesel at all.

Now to a question you haven't asked. What is the fuel consumption of the 30 hp Yanmar in a R-21 EC? At approx 80 hours of operating time I'm averaging 0.6 gph. I spend about 8% of the time flat out (3250 rpm), 50% around 2900 rpm, 35 percent at 2000 to 2500 rpm, the remainer entering and exiting the marina and exploring shallow water.

Gene

Keep us posted on that fuel issue.

 

[Two killicks]

I know that this is an old post, but I'd like to add that my tug goes all the way to 3800 rpm at WOT... I get similar fuel consumption as Gene. I mostly run the tug at 2200 RPM, it seems to be the sweet spot at this RPM for my tug.

 

[rt11002003]

I've just returned from a couple of hours on the water. This R21EC, my 3rd, has a top end of 8 knots in flat water, 2 knots of breeze, running at its max rpm, per tach, of 3000. I've only gotten 45.2 hours on this boat, but it seems it might burn more than my usual average of .6 gph. Not much more, m/b .65 to .7 gph. They are miserly.