NEW BIGGER GAS TANK

[Fyathyrio]

Yeah, the old tank catches on the back, inside corner, and all the Tetris in the world won't get it out without scraping it a bit on the seat mount. Even after bolting the frame back together, the new one pretty much just drops in despite having 50% more capacity. Next trick is getting the fuel pump lock ring off. I tried a trick I've used in the past with a motorcycle clutch gripper tool, but this ring is too tight, so I hafta hunt down the special tool in rural UT or wait for Amazon in order to finish the install.

 

[Admin]

 

[prostreet66mustang]

The trail tank was my first update. For me and my driving a must. With the stock tank and playing hard which is what I bought my for I was getting around 110 miles per tank on the stock. Yes I know if you run it easy it will get more miles as had that happen on stock tank and only 1 1/2 Gal. back up. The trail tank is a lot better quality. comes out from the top and flexing the stock one to get it out is the only really thing that you have to do. It dose cover up one of your drive line loop bolts that you will not be able to remove. So check the U joints while your in there.The bottom pick up is just like to stock and everything fits really nice. Yes the price but then what is not over priced on these toys. Pay to play.

 

[HavasuDave]

The trail tank was my first update. For me and my driving a must. With the stock tank and playing hard which is what I bought my for I was getting around 110 miles per tank on the stock. Yes I know if you run it easy it will get more miles as had that happen on stock tank and only 1 1/2 Gal. back up. The trail tank is a lot better quality. comes out from the top and flexing the stock one to get it out is the only really thing that you have to do. It dose cover up one of your drive line loop bolts that you will not be able to remove. So check the U joints while your in there.The bottom pick up is just like to stock and everything fits really nice. Yes the price but then what is not over priced on these toys. Pay to play.

And soooo much easier to fill up!

 

[Fyathyrio]

Well, it's all over but the shouting, just a few panels & the seat to go back in. Some things I noticed in no particular order . . . I figured I would write them down while waiting for the garage to cool off a bit. Good news is I bled a little, sacrifice was given, this job will be successful first try! 🤣

- I did this with about 1/4 to 1/2 gal of fuel left in the tank, it could easily & safely be done with a gallon or more, you don't have to run it dry and risk burning up the fuel pump.
- A gunsmith style "Fat Wrench" or similar will help getting the fuel pump ring evenly snugged down. A T30 bit is needed for the TT provided screws.
- If you haven't done so, remove the inner sleeve on the stock tank fill hole, it will make pouring the last bit of gas out simple.
- Silicone dielectric grease will help preserve the fuel pump seals and promote sealing, too. Just a light coat.
- My rubber tank cushions on the floor of the Talon had come loose, they are just glued in place. I reattached them with some contact cement. Somebody posted earlier that he felt they were too tall, and replaced with some 1/8" thick stuff he had. I prefer my gas tank pads like I prefer my liberty; I'd rather deal with the problems of too much vs too little. Everything squished together nicely with the stock pads and stock tank hold down bolts.
- Put the metal sleeves in at the same time you put the rubber grommets through the front mounting brackets, they won't fit after the bracket is screwed in place.
- The special tank ring removal tool isn't all that special, lots of places have it, search for the 6599 number or check your local VatoZone. I found it quite easy to stand the tank on it's flat edge and then pop the ring off, half a jack handle gave enough leverage. Trying to remove it with the tank flat on the floor will just lead to chasing the tank around your garage like it's a greased pig.
- Don't be surprised if your pump looks about an inch too tall once you set it in the new tank, it's spring loaded, press it back down gently.

 

[Fyathyrio]

Well, I've figured out why there's a strong smell of fuel in the cab, at least in my case. Even after swapping in the Trail Tank, I had the same smell, same level, under the same riding conditions. Turns out the vent hose going into the frame is clogged, or at least severely restricted. Just like the issues some have with the clogged diff vents blowing oil out the axle seals, the plugged vent forces fuel vapors out of the pump/tank somewhere. The tank & fuel pump end of the vent has no restriction or check valve, blow air in and it will come right back out once you release the vent hose.

I used this kit from Amazon that comes with 6' of decent, reinforced 1/4" fuel line and two filters & some clamps. I pulled the connector near the shifter and used one filter to connect the new line to old as well as have a visual indicator for if raw fuel is coming out the vent. I ran it up the tunnel and around the driver's side frame, across the front, and tucked the open end along the side of the radiator where it's shielded from pretty much everything up to waist deep water. I put the 2nd filter at that end to keep junk out of the hose.

Tonight, I filled the Trail Tank to the bottom edge of the filler neck, and then I hit the trails. Riding temps ranged from 80s to 50s, elevation from 6k ft to 10k ft, bouncing along & drifting turns, and never a hint of fuel smell.

 

[HavasuDave]

Well, I've figured out why there's a strong smell of fuel in the cab, at least in my case. Even after swapping in the Trail Tank, I had the same smell, same level, under the same riding conditions. Turns out the vent hose going into the frame is clogged, or at least severely restricted. Just like the issues some have with the clogged diff vents blowing oil out the axle seals, the plugged vent forces fuel vapors out of the pump/tank somewhere. The tank & fuel pump end of the vent has no restriction or check valve, blow air in and it will come right back out once you release the vent hose.

I used this kit from Amazon that comes with 6' of decent, reinforced 1/4" fuel line and two filters & some clamps. I pulled the connector near the shifter and used one filter to connect the new line to old as well as have a visual indicator for if raw fuel is coming out the vent. I ran it up the tunnel and around the driver's side frame, across the front, and tucked the open end along the side of the radiator where it's shielded from pretty much everything up to waist deep water. I put the 2nd filter at that end to keep junk out of the hose.

Tonight, I filled the Trail Tank to the bottom edge of the filler neck, and then I hit the trails. Riding temps ranged from 80s to 50s, elevation from 6k ft to 10k ft, bouncing along & drifting turns, and never a hint of fuel smell.

Any Photos?

 

[CID]

Any Photos?

Sounds similar to what I did back in post 56 (with pics). It's been working for me for over a year and I fill it to the brim every time. Note that it does piss some fuel on the trailer occasionally but I'm ok with that - choices.

 

[Fyathyrio]

Didn't take any at the time, here are a couple after the fact. Going through passenger side would be a shorter run, but the curl in my hose made it easier to get down the tunnel from driver's side.

I kept it in the wire runs low near the shock to avoid the pinch point where shock meets upper frame.

Then I ran it up and across, this avoids sharp bends and makes it easier to tuck the open end safely away. I also had to go around my under hood trunk. The open end is right next to the radiator cap, with a couple inches pointed straight down. This equates to about the level of the seat, if my ass gets wet, the vent is next. I don't anticipte this ever being a concern with where/how I ride, but there is enough slack to run the open end higher if needed.

 

[PaulF]

From the pics provided by @CID and @Fyathyrio, it appears that your extended vent lines droop in a downward routing. Unless you have an EVAP system with a canister that can handle some liquid fuel (like the CA model does), it is never a good idea for a vent line as it can create low spots for fuel to accumulate.

Note that it does piss some fuel on the trailer occasionally but I'm ok with that - choices.

This is most likely cause because you drooped your vent. It is collecting fuel in the low spots when it cools down and condenses and then pushing it out when the tank heats back up and pushes it out the end. You may want to re-route your extended vent line in a slightly upward direction and it will probably eliminate this "pissing".

 

[Fyathyrio]

I just topped the tank off from the ride last night, and the sun will soon start heating the garage, I'll see what happens then.

 

[PaulF]

I just topped the tank off from the ride last night, and the sun will soon start heating the garage, I'll see what happens then.

It is not going to happen every time and a near empty tank will have more vapor expansion than a full tank so your parking in the garage with a full tank will probably yield nothing out of the ordinary.

The scenario to make it piss would need for raw fuel (or vapors to collect and condense) in the line, the tank to heat up and vapors to expand. Most likely scenario is after a hard ride, 1/2 tank or less, park in the sun for a while.

 

[CID]

From the pics provided by @CID and @Fyathyrio, it appears that your extended vent lines droop in a downward routing. Unless you have an EVAP system with a canister that can handle some liquid fuel (like the CA model does), it is never a good idea for a vent line as it can create low spots for fuel to accumulate.


This is most likely cause because you drooped your vent. It is collecting fuel in the low spots when it cools down and condenses and then pushing it out when the tank heats back up and pushes it out the end. You may want to re-route your extended vent line in a slightly upward direction and it will probably eliminate this "pissing".

While I tried to keep the run uphill to the high point and then downhill to the exit (under the winch), this is possible. I think it happens when I fill the tank (FULL - I know you don't think this is a good idea, which is OK, different strokes - ) and then it warms up expanding enough to fill the vent line (only a few ounces - 6' of 1/4" tubing).

 

[PaulF]

While I tried to keep the run uphill to the high point and then downhill to the exit (under the winch), this is possible. I think it happens when I fill the tank (FULL - I know you don't think this is a good idea, which is OK, different strokes - ) and then it warms up expanding enough to fill the vent line (only a few ounces - 6' of 1/4" tubing).

That explains it, you are overfilling your tank. Your hose routing will make little difference in that case. If I overfill my tank like you do and drive the way I usually do (especially dunes), mine PUKES fuel everywhere and basically leaks out some of the extra fuel so it really does me no good to overfill. The first time it happened to me, I had fuel all over the skid dripping on the sand and I thought I sprung a leak or ruptured the tank. Under certain driving conditions, it can get pretty bad if you overfill.

The neck in the tank has a specific purpose and if you bypass (pull it out or keep filling after fuel reaches the bottom of the neck) you eliminate any room for the fuel to expand and you get raw gas out the vent (or worse if a CA model with the evap. canister) Extending the vent and overfilling the tank like you do just makes the fuel puke out somewhere else, not eliminate it.

I am not totally against overfilling the tank, I just can't the way I normally use my machine. Dunes and Rock Crawling in 90 degree heat stir up the tank too much and fuel pukes everywhere. IF I am on a "less aggressive" dirt type road long ride and I can burn off the top of the tank before I get wild, I do put more fuel in but that is pretty rare.

What I am against is a lot of folks suggest pulling the plastic neck without explaining WHY the neck is there and what the drawbacks are if you remove it.

 

[CID]

That explains it, you are overfilling your tank.

Yes, I am.

What I am against is a lot of folks suggest pulling the plastic neck without explaining WHY the neck is there and what the drawbacks are if you remove it.

I only snipped the rest of your post so I could highlight this thought.

For those new to the thread - the purpose of that plastic filler neck is to trap a 1.3 gallon air bubble so a full fuel tank (7.3 gallons on a 2 seater, per Honda's spec) has room to expand when exposed to increased temperatures or normal SxS tilt angles. Fuel and its attendant fumes are highly explosive and Honda would be held responsible for that.

 

[PaulF]

And while we are discussing the plastic filler neck tube, does anyone have one that is still usable? I bought another used machine and the previous owner removed it and I want to put one back in.

PM me if you have one you want to get rid of.

 

[Fyathyrio]

It is not going to happen every time and a near empty tank will have more vapor expansion than a full tank so your parking in the garage with a full tank will probably yield nothing out of the ordinary.

The scenario to make it piss would need for raw fuel (or vapors to collect and condense) in the line, the tank to heat up and vapors to expand. Most likely scenario is after a hard ride, 1/2 tank or less, park in the sun for a while.

My test is perfectly cromulent for my needs, that is why I chose it. With the clogged vent, vapor pressure forced raw fuel (drips on garage floor) out of the system at other, unintended points when the tank was full and the sun was shining on it while parked in the garage at summer time ambient temps. This did not happen once about 1 to 2 gallons was used, or it would briefly stop if I opened the fill cap and allowed the built up pressure to whoosh out. Now, with a free flowing vent, I have no drips and no smell of fuel; all is well.

Vapor pressure is related to temperature, not volume. The tank will reach the same pressure no matter the amount of fuel inside for a given temp. It may take slightly longer for the larger volume to fill to the pressure, but that should be negligible for our purposes here. The key takeaway is that now the vapor pressure in the tank is equal to ambient pressure with a repaired vent that can breath.

 

[SLOWPOKE693]

You guys modifying your filler necks and installing larger tanks need to consider using the FATS method when rerouting your vent lines. Doing so will absolutely ensure that no matter what angle you are at, even upside down, no fuel will be able to leak out and potentially start a fire...

 

[PaulF]

You guys modifying your filler necks and installing larger tanks need to consider using the FATS method when rerouting your vent lines. Doing so will absolutely ensure that no matter what angle you are at, even upside down, no fuel will be able to leak out and potentially start a fire...

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What happens when you go into water, cool the tank down and create a vacuum? Will this FATS system suck water in because the filter is under water?

I do know for a fact that stock tank/vent system properly filled to the bottom of the safety neck will not leak if the machine sits on the left side, the right side or even the top so this is another reason I just leave mine stock. The extra gallon you get by removing the neck/overfilling just isn't worth it to me. The rare times I need more that the stock 7.3 gallons, I take along a RotoPax.

If I needed the extra capacity more often, I would consider the bigger tank as long as it also has expansion room like the stock tank.

 

[SLOWPOKE693]

I don't drive in water so no problems here. If your tank gets hot enough that when it cools it will pull water through the entire vent line you have other problems. 😁 Mine is still 100% stock and so is my filler neck. I don't burn enough fuel per race to require a bigger tank or any vent line tricks. Next year will be a different story and I may be going to a fuell cell for more capacity and a return style fuel system to keep up with the engine demand. I'll be using the FATS method on that one when it happens.

If the stock vent system doesn't leak when the machine is on its sides or upside-down their has to be a rollover valve built into the sending unit. That makes me feel a little better about having the stock vent line still in place.

 

[Fyathyrio]

If I needed the extra capacity more often, I would consider the bigger tank as long as it also has expansion room like the stock tank.

The trail tank does have expansion room, it has a larger top volume compared to stock, and it is impossible to overfill the tank beyond the bottom of the fill neck unless you jack the passenger side up to bout a 45* angle. The vapor space is part of the tank design without a bandaid filler neck.