R21 Fuel tank limits, last 1/4 tank unusable

[bjp447]

I remember reading about this somewhere in Tugnuts but can't remember where.
(Got the over 65 CRS problems)
On my 98 R21 I have a 12 gal fuel tank. I usually keep it over 1/2 full, but have been running it
lower lately. Today I had it idling at the dock and the motor coughed and died, I tried to start it
and it acted like it was out of fuel - I still had a bit over 1/4 tank left. I checked the Fuel filter
bleeding nut and it was dry so I added 2.5 gallons and problem solved.
My question is does anyone else have a problem with starving for fuel with 3 or 4 gallons left in the tank,
and if so is there a solution?
I seem to remember a thread about the engine not being able to pull the fuel when it got below a certain point
but I thought that was also in heavy seas, not at the slip

 

[abcandjrc]

Yup, yup, yup..... Here's my recent post concerning that:

viewtopic.php?f=2&t=2557

 

[RProffer]

It looks like bjp447 has a classic R21 and the factory mod is for the R21-EC with the 18 gal tank with the threaded in fuel pickups.

bjp447 - can you determine if your fuel pick-up goes all the way to the bottom of the tank? Maybe the pickup is too short, or maybe it developed a crack and is sucking air. Things to look at.

A couple of R21 Classic owners moved their fuel tank from the engine compartment to the aft bench. If you search the blog, I am sure you can find the description and pictures. Moving the tank might solve your problem and give you a bigger tank at the same time.

 

[abcandjrc]

Understood. I just wanted to point him to the post in case that was the one he remebered. I figured it was from the comment about heavy seas. As I recall from my searches for the problem there are several other threads about fuel starvation as well.

I wonder if it is even possible his pickup tube has broken short of the bottom of the tank since it happens with the boat in a slip.

 

[bjp447]

Thanks, Going to check the tank today. That's why I like you guys,
I forget to check the simple stuff, you keep me on my toes.
I started worrying that I had a bad fuel pump.

Bruce

 

[SlackwaterJack]

When I installed a new tank in my '05 R-21 I noticed that the pickup tube was approx 3/4 in from the tank bottom (I assume so it doesn't pick up the crap that can accumulate). The tube is pretty much dead center so I imagine if tilted (even at the slip an R-21 can noticably tip from crew movement) I would think that a quarter tank quarter tank reading that you assume to be 3 gallons could be much less depending on the guage location, accuracy, over it's lenght of travel, etc. I figure that my new tank if filled while level would take a gallon just to touch the suction tube and 3 wouldn't guarantee 100% immersion at all points of heel.
I"m pretty sure that if you actually siphoned out every drop that was in that tank you'd find that there was less fuel than you thought.

Best solution? ... Don't keep it at 1/4 full according to the guage as that is apparently it's actual "empty" point. There's absolutely no reason to NOT keep the fuel tank topped up. On these boats the difference between running out of fuel in the slip and a full tank is about $40 plus $12 to fill a small fuel can. Use the small one to fill the tank after each use and when it is gone take the small can home, re-fill it, and bring it back on your next visit. That small fuel can is good for about 10 hours of run time (maybe more).

On the bright-side...I can't think of a better place to run out of fuel than tied to the slip.

 

[RProffer]

I am kinda anal about ensuring I have enough fuel in my boat (and my cars\trucks for that matter). In my other boats, I always filled my tank and carried extra gas cans. My other boats usually consumed a full tank before I made it back to the dock. With my R21-EC, I can go all day long and into the night and not burn more than 5 gal of diesel. At that rate, I can get three days of cruising and have a little reserve. But, as a precaution, if I am taking overnight or weekend cruises, I will carry a spare can of diesel. I still top-off before launching the boat - usually from gas cans. I don't like over-filling my boat at the gas station. I am less likely to over-fill my boat from gas cans.

 

[tlkenyon]

Just for safety, I take my fuel tank and dump it completely out every once in a while to make sure there is no accumulation of anything. Kinda nice to be able to do that with the original Classic fuel tank arrangement.