Where is the Metering jet on a Mille GT?

[MGBreva2007]

I bought a new tank for my Mille GT and it doesn't have the vent hose so the tank is pressurizing.  Guzziology says I can plug the metering jets to fix the issue but I can't find any reference to metering jets anywhere.  The bike is stock as far as I know.  Has anyone done this? 

[Wayne Orwig]

Isn't the cap vented?

[MGBreva2007]

I think it is but I still get the pressure build up. 

[RinkRat II]

 The metering jet your referring to is on the stock tank vent line as some emissions models used a non vented cap and utilized a vent hose with a restrictor in it.  The best bet at this point is to use a vented cap.
     
        Paul B

[Idontwantapickle]

I bought a new tank for my Mille GT and it doesn't have the vent hose so the tank is pressurizing.  Guzziology says I can plug the metering jets to fix the issue but I can't find any reference to metering jets anywhere.  The bike is stock as far as I know.  Has anyone done this?

Does it have the tube at the front of the tank but it is blocked off or is that missing from your new tank entirely? If it's missing then get a vented cap as RinkRat suggested. If it is simply blocked with a screw as some are you could remove that screw, install the restrictor which is a delorto pilot jet and connect the tube.
Here's a link to for the cap:
http://www.mgcycle.com/index.php?main_page=product_info&products_id=3259

Or someone here on WG may have one to offer.

Hunter

[MGBreva2007]

The original tank has a nipple at the top front that had a vent hose on it.  The new tank doesn't have the vent at all.  The cap looks like the one I have.  I took a pic of the underside and it says ventilazione controllata.  Is this the vented cap? 

[Old Jock]

Well according to Google that is "Controlled Ventilation" but the cap looks like a rubber diaphragm, that might not vent at the low pressure required

Again +1 for Rinkrat's suggestion by far the easiest solution

Otherwise you are probably looking at drilling the tank and installing a vent fitting with a low pressure check valve into the tank

I replaced the standard cap on an 1100 Magni and had no idea what type of cap it used. I contacted Oberon who make different aftermarket caps and they went above and beyond to help me get a suitable replacement. They are British however (I'm in the UK).

I'm just telling you this as if you do some measurements and take detailed pictures of the cap and send to a manufacturer of aftermarket caps there is a good chance they will be able to help you out.

Pretty sure the tank supplier would make the tank to fit some sort of cap that's used on other motorcycles, I'd be stunned if they were specials.

[Testarossa]

Why not just drill thru the cap with a 1/16 bit?

[Idontwantapickle]

Why not just drill thru the cap with a 1/16 bit?

That's probably doable, I recently disassembled a gas cap to repair it on my LeMans, it was clogged. It's pretty easy. I used some pliers to gently bend the crimped outer shell open slightly and it comes right apart. Then you could drill the middle layer to vent similar to how the vented cap is made. Hold it together firmly and peen the outer shell back around the edges gently with a hammer and Bob's your Uncle. I don't remember specifically but it may be necessary to "modify" the rubber seal inside the non-vented cap to allow it to vent properly.
If you are at all handy and have pliers and a hammer (Harley content) then it'll work out fine.

Hunter

[Antietam Classic Cycle]

The original tank has a nipple at the top front that had a vent hose on it.  The new tank doesn't have the vent at all.  The cap looks like the one I have.  I took a pic of the underside and it says ventilazione controllata.  Is this the vented cap? 

Under the rubber gasket, there should be a metal ring of the same size, but with a "slice" out of it. That is intended as the vent, at least on the one I have anyway. If the metal ring is missing, it may not vent.

[nc43bsa]

That's probably doable, I recently disassembled a gas cap to repair it on my LeMans, it was clogged. It's pretty easy. I used some pliers to gently bend the crimped outer shell open slightly and it comes right apart. Then you could drill the middle layer to vent similar to how the vented cap is made. Hold it together firmly and peen the outer shell back around the edges gently with a hammer and Bob's your Uncle. I don't remember specifically but it may be necessary to "modify" the rubber seal inside the non-vented cap to allow it to vent properly.
If you are at all handy and have pliers and a hammer (Harley content) then it'll work out fine.

Hunter

Spoken like a true Hammer Mechanic!   

[MGBreva2007]

I'll try ordering a new cap.  Thanks all.