Stupid plastic gas tank warped & leaking!

[gts455]

yea my tank is warped a bit. i ended up putting the racing tank pins in (which helps a lot) and removing the spacer because the bolts were not fitting anymore. just wasnt lining up. it also has a small lump on top....but has not leaked yet.....pleeeeeaaasssse god do not let it leak.

[2pist]

Try opening the gas cap before refitting the tank. It works miracles.

[GrafX Squid]

Or sacrifice a nut for the Sebimoto CF tank.

http://www.yoyodyneti.com/ProductInf...ctid=SA011041C
Guaranteed not to warp.

[danman]

Try opening the gas cap before refitting the tank. It works miracles.

So what is that supposed to do? I could see an issue if the vent system was plugged but mine was clear.

[2pist]

So what is that supposed to do? I could see an issue if the vent system was plugged but mine was clear.

Clear until you raise the tank and pinch the vent tube. Mine always has pressure in it after I raise the tank. Could be unique to my circumstances but it's worth a try.

[Bram]

I was going to post some photos of the leaking tank but my little one decided to play with my camera and has done a good job in killing it, so a new one is on my list for Santa next year.


The good news is that I have fixed my leaking tank, I know there have been a few fixes on here but if anyone is interested this is what I did.

1) Removed the two bolts at the front of the tank near the headstock. They were tight probably due to the tank warping so it would be a good idea to open the fuel cap up which may allow it to move a bit more by releiving the pressure.
2) Removed the rear tank bracket (4 bolts at the rear of the tank).
3) Removed both vented side panels.
4) Pivot the tank backwards so you can see the fuel pump flange.

This is where I made a mistake !

I removed all the bolts and then slid out all pump the internals which enabled me to put the tank on a work bench and leave the fuel pump still connected to all the pipes at the bike. My thought was that I can push the bottom of the tank into shape and give the mounting face a good clean. Then I was going to clean the face of the fuel pump and the 'O' ring and then put the sealant over the tank face.
My plan then was with help of a mate to slide the fuel pump back into the tank and tighten the bolts up with out the need of disconnecting the fuel lines and electrics.

Don't try this as it does not work, it's it virtually impossible to to slide the pump inside the tank without messing up the gasket sealant.

The best way is to remove the pipe work and the electrical connector from the pump with the tank still attached, then you can take the tank with the pump still attached to a work bench. This is then far easier to remove the pump from the tank.

5) I then removed the bolts from the pump and removed the pump from inside the tank.
6) I then used a rule to check how bad the tank was warped and then pushed it back into position as best I could by hand.
7) I then cleaned the face of the tank with WD40, and removed any high spots and old sealant by scraping a stanley knife over the bottom of the tank.
8) I then smeared Worth Engine Sealant over the underside of the tank where the 'O' ring of the pump would sit. I then left the sealant to slightly harden for 10 minutes.
9) I then re-fitted the pump and torqued up the bolts to 8Nm. Note the pump only fits in one way so to avoid making a mess of the sealant take a photo of the postion of the pump before you remove or at least make a mental note. Don't do what I did as I tried to fit the pump back the wrong way and had to re-clean and re-fit again as I messed all the sealant up.
10) Then re-fit the fuel line and other pipe and re-connect the electrics and re-fit the tank.
11) I then left the bike for a day to cure and then filled it up with fuel. Then fired her up and after a few turns to get the fuel to the engine the twin Akra's came to life.

Worth engine sealant is not the cheapest on the market but it is resistant to fuel and (so far) seems to have worked for me.

I did this over a week ago and there is still no fuel leak.

If anyone wants any more help let me know.

Cheers

[Db71]

Ok I don't know how this will turn out yet but I bought some seal all from auto zone put a layer of tape around the inside lip of opening to create a dam then used several layers to build it up now waiting on last to dry then going to uses razor to trim it level and reinstall. Wish me luck

[socalsteve]

I used epoxy putty to refinish the sealing surface. Works perfect.

[Db71]

I used epoxy putty to refinish the sealing surface. Works perfect.

What brand did u use and what did u use to resurface?

[socalsteve]

What brand did u use and what did u use to resurface?

I used whatever they sell at home depot. I do not like the JB Weld brand (of anything) as I recently had to rework a repair on something else where that was used and it was too rubbery.

It took a couple applications to get the surface leveled and I used a sanding block with some fine grade paper. This stuff works very well. I have used it many times and you can work it just like you wold do with wood, metal or plastic.

[Db71]

Thanks

[Jdmage_mx5]

Ok i called MFP Seals to order the OR-425 o-ring to replace mine as i am battling the warp flange problem but ran into another problem. I found where they have the fluorocarbon o-rings but they had two different types as far as stiffness goes a 75 and a 90, which is the right one and does $13 sound about right for the price? Just want to make sure i get the right o-ring. Thanks.

[jbruce865]

i had the same prob with my '02...take the fuel pump off and sand down the tank...get a new ring and put it back on...it took some time but got it to work...haven't have a prob with mine for over 2 years now...

[Diablo1]

Ok i called MFP Seals to order the OR-425 o-ring to replace mine as i am battling the warp flange problem but ran into another problem. I found where they have the fluorocarbon o-rings but they had two different types as far as stiffness goes a 75 and a 90, which is the right one and does $13 sound about right for the price? Just want to make sure i get the right o-ring. Thanks.

Get the softer o-ring - #75, as it will conform better to any irregularities.

[Stanleybobly]

hope this helps:
after trying any thing what here said, nothing helped for me.

one last try, before I put a new used tank on it.

I tried this:
heatgun

use heatglows and a thick towel
remember to open up the tank fillingcover and empty any fuel in it.

I heated up the area of the pump flange that was warped, after a plenty warming the plastic, you could feel the heat coming of.
PA6 plastic needs 225 C degrees to meld, so before 200 is a good starting point.

I pulled/pushed back the plastic lid with my fingers and put a towel between my fingers and the tank. it;s bloody hot to burn your fingers without it. keep the pushing/pulling 30-60 sec. or so when you leave your pushing you'll see that the warped area flattens and stays there !
did all the areas between the bolting holes,wetsanded the area until 1200 grind sandpaper, to smoothen,
used the Loctite 518 (without also succesfull, but I had it lying here) and the original 10 year old o-ring.


now LEAK FREE !!!!!!

if your bolting holes are warped, so pulled up by bolting to much torque on it, screw a large bolt in it, heathen the area and push the bolt down to flatten. remember your fingers it's damned HOT,....




this way is even better than epoxy/sanding or money waisting expensive sealants.

plastic is so fantastic