petrol tank goes vacuum

[Minimax]

When I drove my car today, for the fist time with longer periods, I noticed that it was having trouble getting the petrol to the engine.
I opened the petrol tank and a heared it sucking for air.
What is wrong that it goes vacuum?

Another thing I saw was that the front wheels were spinning alot when accellerating. The rear comes to the tarmac and the front is lifted a bit.Do I have to put some weight in the front? Or should I stiffen the rear dampers?

Thanks for teaching a newbie...

[cabbie]

Check the vent hole in the fuel cap, or fit an extra valve

http://www.baja-forum.co.uk/showthread.php?1053-Fuel-tank-vent-mod

Don't worry about the front wheels spinning.

[Minimax]

a vent hole in the fuel cap...

I bought a CNC machined fuel cap because I read somewhere the stock fuel cap was leaking. And I didn't want that in my trunk.
So it must be able to breathe?
It is not like with Nitro that there should be some pressure build up by the exhaust.

[Pipeous]

exact opposite to a nitro. on my fg I run a line from the tank to the back bumper to breath. I just plug the tube with a screw or nail when in the house and in transit. the caps have a diaphragm. common thing to go bad. I'll see if an fg cap fits tomorrow. the off roads use the same thing on their tanks. on roads have a breather line (well not all but the solo tank does ... before someone corrects me :P )

the carb has a pulse port to fuel the engine. a common problem there is people block that when replacing gaskets or using rtv sealant

[cabbie]

a vent hole in the fuel cap...

I bought a CNC machined fuel cap because I read somewhere the stock fuel cap was leaking. And I didn't want that in my trunk.
So it must be able to breathe?
It is not like with Nitro that there should be some pressure build up by the exhaust.

There is a rubber inner to the fuel cap, this has a hole, check it's open, these Petrol engines suck fuel so no tank pressure is needed from the exhaust.

[Minimax]

The rubbers are put in the CNC cap, and indeed the hole is open in the rubber, but there is no hole in the CNC.
There is a hole in the original cap.
Should I make a very smal hole in the cnc? As in the original plastic one? Or should I go for the extra tube?

[Pipeous]

either a hole in the cap, or add a nipple like on nitro exhausts. you can vent a tube from that

[sickboy]

Hi Minimax
you say you have the cnc petrol cap then there should be a hole to vent ,its about a 1mm diameter
I have the cnc cap here and this has the vet hole .
Just take the cap off take the rubber seal out then you can drill the hole in the center of the cap ,don't forget 1 mm diameter ok

[Clubin]

I had to install 120,000 in my centre diff, it had grease in it and it provided no resistance, it acted like a front wheeel drive till I put the diff fluid in, I put 50k in the front and 50k in the rear.