Even MORE Acerbis

11 replies to this topic
  • thumpsalad

Posted January 12, 2002 - 07:45 PM


Hey all,

I just got my Acerbis 3.4g tank and installed it with no problems. I have 2 questions about it, tho.

1. How hard does the carb on my bike actually "pull" the fuel? I ask this because of the way I routed the fuel line on the kickstart side of the bike. I ran the line Up and over the back of the carb to keep it away from the throttle assembly and hot engine parts.

2. On the same side of the bike the tank is fairly close to the header pipe, which as you all know on these bikes, gets VERY hot. Especially when you are sitting still. Is this something to be concerned about? Should I fab a shield of some sort? Thanks for any input. This site rocks!


  • kc_husky

Posted January 12, 2002 - 08:10 PM


Hi Thumpsalad,

The carb is feed by gravity. The straighter the hose the better it will flow. As log as you don't have any part of the hose lower than the fuel inlet on the carb you should be ok.

As far as heat if you feel the tank is to close to you pipe, then you should get some kind of heat shield.

Hope this helps. :)

  • thumpsalad

Posted January 12, 2002 - 08:34 PM


Well, it's nearly impossible to keep the fuel hose above the fuel inlet since the petcocks on both sides are below the inlet to begin with due to the sides of the tank sitting very low on the bike.

The petcock on the left side of the bike is almost at the same level as the inlet and riding the bike for awhile seemed to work ok. I am just concerned about the petcock on the other side being able to deliver fuel.


  • kc_husky

Posted January 13, 2002 - 03:13 AM


Does your new tank have reserve on either pet cock? If so I would use the right hand side first, if I under stand correctly that it's the side of most concern. I don't think you are going to be able to get every once of fuel out of that tank, but I could be wrong?

[ January 13, 2002: Message edited by: kc husky ]

  • motojunkie

Posted January 13, 2002 - 03:30 AM


As long as you keep the level of fuel above the carb inlet, you'll be fine.

  • thumpsalad

Posted January 13, 2002 - 09:05 AM


Now, as far as the heat from the header...

I have heard of some racers using a type of foil shield that can be found in automotive stores. Is this true and is it effective? Can it stick to the tank? Do any of you think a metal shield would be better that would deflect the heat? My truck actually has a shield like this between the catalytic converter and the underside of the cab. Must be for re-entry! :)

Any tips wold be appreciated!


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  • MN_Kevin

Posted January 13, 2002 - 12:46 PM


If you have a check (one way) valve in your tank vent, REMOVE IT!!!

I recommend removing those stupid things anyways (required by the EPA??).

The heat from your exhaust will heat up your fuel. This WILL PRESSURIZE your tank greater than ambient pressure.

When/if your float drops, the pressurized tank and now pressurized FLOAT BOWL will give you jetting/running problems the human mind cannot comprehend! :)

The check valve only allows air to be drawn in as the fuel leverl drops, not let any expansion out. If the weather gets warm, or the fuel comes out of the pump cold, your tank will become pressurized over time.

There were LOTS of comments on this exact phenominon on the WR websight a couple of years ago.

  • Flamed1

Posted January 13, 2002 - 02:00 PM


I too have the Acerbis on my 2001 YZ. I did not use the "Y" provided for the fuel line but used a 'T' for the fuel line. I also upgraded the line from the flimsy stuff they included and added fuel filters too. Try steel braided line if you are concerned about the header. I have also heard of some using the heat shield material or wrap for added protection. Both of my lines are a little below the carb inlet too and have had no problems with fuel delivery. As you said, there is no choice. I added a piece of neoprene around the line on the right side of the bike and used a zip tie to keep it up and out of the way. :D I also do not use the right side petcock unless I have to and then I use it in the reserve position to avoid the header. Also, you might want to check the clearance between the shock reservoir and the tank. :) Mine has contact so I used a piece of neoprene there too as I tried to adjust the tank with no luck.
Good luck,

  • Hick

Posted January 13, 2002 - 05:22 PM


It doesn’t matter one lick if the fuel line extends below the carb inlet. You could run the fuel line to Hades and back up and it wouldn’t matter. As long as there is gas in the tank, all of which should sit above float level, gravity dictates that it will end up in the bowl (the gas in the mile of line to Hades and back notwithstanding). Just thought I’d point that out.

I have this tank and long suspected it held less than advertised. I’ve never gotten around to checking it. But I have run it dry, there wasn’t two drops of fuel in the tank when my bike finally starved. If I’m just play riding I leave the right petcock off, during a race I go ahead and run both on reserve. I also tossed the cheap fitting and fuel line that came with the tank, I use a brass T fitting between the left petcock and carb and automotive fuel line.

I also put header wrap on my (stock) header, covering the portion under the heat shield. More for piece of mind than anything. I also have a check valve on the tank vent, always have, and haven’t experienced the pressurization problems pointed out by Kevin, although that seems like a legitimate concern. I live and ride in the Chihuahua desert (it gets hot here).

But this tank would not fit with my old PC T4 header, I don’t know about other brands but I’d say I have 1 to 1-¼ inches of clearance between petcock and stock header.

Hope this helps.

[ January 13, 2002: Message edited by: Hick ]

  • thumpsalad

Posted January 13, 2002 - 05:35 PM


Wow, thanks for all these tips!

So, that one-way valve connected to the fuel-cap breather hose really doesn't do squat, does it? I have been riding the bike in good weather, about 75F and have not noticed anything good or bad with that valve...so, what gives?? Can I really dump it?

I changed out the "Y" adapter and got a much beefier unit...couldn't find any bronze, so I opted for an automotive plastic/PVC type. Much nicer. I also replaced the fuel hose that shipped with it. Too flimsy! The hose clamps from the factory were crap, too. I ran all my lines as even as humanly possible and without too many twists and turns. Looks like it will work! This tank is very nice, but some of the other items designed to go with it are sub-par. No big deal, tho.


  • John_H

Posted January 13, 2002 - 05:48 PM


I've got that stupid little valve on my gas cap hose too. It's the stock setup except with my steering stabilizer and pro tapers, it just flops around instead of routing down the steering head tube. Anyway, the girlfriend ran into my bike today and down it went (I keep telling myself she's just learning) and fuel poured out of the wonderful one way valved tube. I just took it off.

One thing for sure on a gravity feed system. Must have airflow.

BTW, there was a post somewhere a few months back about the Acerbis tank and routing the hoses. You might do a search and see what they had to say.

  • thumpsalad

Posted January 13, 2002 - 07:02 PM


Yeah, I think I will take the one-way valve off and see what happens. I have a 60-mile Poker Run coming up on Saturday, so this will be my first outing with the new tank. The bike is dialed in, so the tank just needs a few laps around the block to verify all is well! Thanks for all the replies, guys!


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