Wont run unless Gas cap is loose By tomtom (Read 1,125 times)

[tomtom]

Alleyoop

I hate to pester you with something that I feel I should be able to handle.
Sometimes you will be able to easily guide me to the problem.
To refresh you as to what scooter is having the problem. 2012 Gorilla Motor Works V150 (ZNEN)
just let me know if the vacuum system is involved with the tank venting or what. I honestly don't understand what comes into play with the vacuum on a small engine. Thank You
 Tom Tom

[cyborg]

Classic tank venting issue,,,drill a very small hole in the cap and the problem will disappear

[Alleyoop]

On most newer models they put an EVAP system which ususlly consist of a small collection canister and a Charcoal Canister to trap the fumes and feed them back into the motor by way of a hose from the canister to a connector on the AIR TUBING going to the carb. So in theory the fumes from the gas tank will be reburned and not get into the AIR .

The Canister is OPERATED by Vacuum and you will have a Vacuum hose from the Charcoal canister connected to a "Y" or "T" which eventually comes from a connector on the INTAKE MANIFOLD.

Now If for some reason GAS gets into the vent hose from the tank and blocks and or soaks the Charcoal in the Canister then the GAS TANK no longer can Vent and usually what happens is GAS WILL NOT FLOW out of the GAS TANK to your PETCOCK/FUEL PUMP and to the CARB.
Hope this explains the EVAP system.

When things happen with the EVAP system IF you do not live in a state where you have to have your scoot tested for pollution the best thing is to TAKE the ENTIRE EVAP system off and just have a piece of VENT HOSE from the gas tank open to the air usually zip tied higher than the outlet just in case as your riding it does not splash out.
Alleyoop

[tomtom]

tomtom,cyborg,Alleyoop

Thank You