Thought I'd share my experience so far with Clarke fuel tank on my 2006 model bike. I'm hoping this helps someone else make an informed decision someday.

I've wanted/needed a bigger tank for a while. With my bike setup and terrain I typically ride, I'm reaching down to switch to reserve at around 100 miles on the trip meter (less if I'm doing single track). Which is not good when the next fuel pump can sometimes be another 100+ miles away. I rode an 4 day 800+ mile trip earlier this year and carried a Rotopax container on the rear rack. Which worked great but was somewhat of a pain as I had to remove the dry bag from atop it to access the fuel every time I needed it. And when I did have to access the Rotopax, I found myself really only needing less than 1 gallon to get to the next fuel station.

I researched larger tanks and found 3 viable options for my 2006 model. The 3 gallon IMS tank, 2.7 Clarke, and 3.7 Acerbis.

From what I could find, the IMS tank could/would result in a very large gap between the tank and seat. Not a deal breaker but certainly less than ideal. Fit and finish were also reported as questionable in some of my reading.

The Clarke tank, although the smallest, seemed to most closely retain the stock look, and fit and finish of the tank was reported as good. I was also drawn to the semi transparent natural color so that one could visibly see fuel level in the tank.

Acerbis was clearly the super tanker of the 3 with regards to capacity, although the last 0.3-0.5gal is rather unusable given that portion was in the wings of the tank- below the petcock. I know a guy could stop periodically/frequently, and tip the bike over to scavenge that little bit of fuel. The Acerbis also definitely had the least stock appearance. One benefit from the Acerbis is that it negates the need for radiator guards since the tank doubles as protection.

In the end, the Clarke tank just checked all of the boxes that were important to me in my decision analysis. Acerbis was a close close 2nd. Truth be told, I very nearly clicked the "buy" button more than once when reviewing the Acerbis before eventually ending up with the Clarke.

For an extra 0.8 gallons, dropping north of $200 for a tank seemed wrong. But whatever - I do need the extra range.

It arrived in a well packed box from JustGasTanks. Build quality is excellent. I inspected all of the mold seems closely and none of them had any apparent issue at all. No apparent thin spots, bubbles, etc. The brass fittings incorporated into the plastic looked great. Cap fit perfectly. Have heard of other tanks arriving with questionable quality and I was relieved this wasn't the case with my Clarke.

I should have weighed the stock tank and the Clarke but I didn't. They felt pretty close to the same by hand. Not a huge difference. Clarke may have been a wee bit lighter but any gains were to be negated by the extra 5 pounds in fuel it would be carrying.

Installation was relatively easy. The most difficult issue BY FAR was dealing with fuel in the stock tank given the fact that the tank itself doesn't have a petcock directly attached, but rather 2 short pieces of fuel line between brass fittings screwed into the tank and a standalone petcock. The stock brass fittings had to be removed from the original tank and swapped over to the Clarke. New O-rings were included. Getting the fuel lines reconnected to the petcock with the Clarke tank set back into place was a PIA also. But it all worked out OK in the end.

The plastics screwed back onto the bike with out any issue whatsoever. I did not have to trim them at all to screw then into place. However, I do have a small gap between the plastic and the seat noted in the pictures and video below. It's definitely an annoyance, but tolerable. Maybe someday I'll spend some calories to try to clean this up. For now, I'm just happy to have more fuel on board.

The top of the tank/cap definitely has more of a bulge to it vs stock. Which could present a problem with my tank bag. Time will tell. I think it can get it to work OK but its something I failed to really notice beforehand.

I really do appreciate the transparent nature of the tank. It is simply fantastic to be able to quickly determine quantity of fuel remaining in the tank.

All on all, I'm happy with my decision. I'll carry the Primus bottles or Rotopax if I find myself needing more than 200 miles on longer trips. But not having to carry extra fuel is going I be nice on the many many journeys I typically ride between 100-200 miles.

 

I have had my Clark on for years, the only change I did was, as after a few rides the Clark gas cap always seemed to leak, so I bought a Honda XR600 gas cap, works much better. I hope that by now they fixed the cap, other than that very happy with the Tank.

 

Hmmm, good feedback. I’ll keep a close watch on it.

I didn’t notice any leaks at all during my test ride and I was riding some fairly rough terrain. As you say, hopefully it’s been resolved.

I do need to install a better vent hose solution. The short piece of tubing I had on there for this ride was strictly temporary to enable me to ride and check for leaks around the bottom of the tank. I plan to ride with a tank bag and have seen others install a 90 fitting at the cap and then route it directly toward the front of the tank. Doing so seems it would enable a bag to sit more or less flush with the tank.

Thanks for the reply.

 

I recently installed an IMS 2.7 on my fuel injected KLX. I highly recommend sticking one of these clever little $6 ebay one-way valves on top of your tube. It allows air into the tank as fuel is being used. It also slowly allows air to escape for heat expansion and completely closes if you tip over to prevent spillage. It'll solve your problem.

As an experiment I ran mine with no cap hose just to see what would happen. Fuel constantly sputtered out due to engine vibration and it smelled like crazy.



I modded my bike to reduce weight and weighed everything I took off and installed.



Curb weight as pictured is 287 pounds. Installing the rear rack adds 3 pounds to 290. The net weight of the IMS with no fuel is 2 pounds lighter than the stock steel tank, which offsets the added 4 pounds of fuel to just two pounds making the curb weight 292 pounds.

 

Thanks for the review of the Clarke tank, I wanted to expand a little bit on my experience with the Acerbis 3.7 gallon tank on my 2006 klx with the 351 big bore. I put the Acerbis on due to it having the largest capacity at 3.7 gallons. I've verified that it does in fact hold 3.7 gallons. I pushed it's range several times over the years and with the petcock that comes with the Acerbis tank I usually have to flip to reserve when I've gone through 3.1 gallons. After switching to reserve I was able to ride until I ran out of fuel at which point I was 1 mile away from a gas station and I didn't have any spare fuel with me. I leaned the bike over to the left almost laying it flat on the ground to get some of the fuel in the right side part of the tank to drain over to the petcock. I was able to restart the bike and ride the 1 mile to the gas station at which point I filled the tank with 3.65 gallons. So there was only 0.05 of a gallon left in the tank which wasn't usable. So the Acerbis tank does have a very much usable 3.65 gallons out of 3.7 which to me was well worth the almost double capacity over the stock 1.9 gallon tank. I went with the Aceribs tank since the 351 big bore gets worse MPG over the stock 250 cc bore, but it makes the klx so much more fun to ride. Hope this helps if anyone is trying to decide on which tank to purchase.

A recent picture from my 1,200 mile trip through the Upper Peninsula of Michigan.