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Old 13-04-24, 12:44 PM   #13
SV650rules
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Join Date: Nov 2016
Location: Shropshire UK
Posts: 1,363
Default Re: carbon fuel tank vent cartridge

OK, I figured it out. The 2016 onwards AL7 ( EURO 4 ) does have a purge valve, mounted under the fuel tank ( see attached PDF photo ) the braid covered hose coming in from Right of photo is one of the pipes from the charcoal EVAP canister. Looking down on the EVAP canister as it is mounted under the seat the hose to the purge valve is the LH hose ( on the nearside of bike ) and the fuel tank breather hose is the centre hose, the RH connection is blocked with a rubber cap held on with a spring type hose clip. With the fuel filler cap closed, if you blow into the fuel tank breather hose you can build up pressure in the fuel tank which blows back out of the pipe when you stop blowing, so that is just a simple connection from the top of fuel tank to the EVAP. The other pipe from canister will not let you suck or blow, this is blocked off by the purge valve ( solenoid valve ) under the fuel tank that opens the pipe to one of the inlet manifolds or maybe even the airbox, so that when engine is running any fuel fumes get sucked back into the engine to get burned. I tried blowing into every connection stub on the EVAP canister ( including taking the rubber cap off the sealed one ) and every port is connected to every other port, including the port on the rear of the canister ( this central rear port will be the normal path for fumes out of the fuel tank when all hoses are connected to EVAP canister and the engine not running - when the purge valve is closed ). What I need now is a 'T' piece hose joiner to connect the two original pipes together and then route a third pipe out somewhere out of the rain ( because water may get sucked into the airbox or inlet manifold if any water gets into end of new tube ). Looks like you cannot simply join the two existing tubes together to bypass the EVAP, because the tank would then try to vent pressure straight into the normally closed purge valve when engine not running. This would cause pressure build up in fuel tank. I have got a 'Y' hose connector and a 6mm connection inline fuel filter off fleabay to route the new exit pipe through to stop any crud being sucked into the purge valve / inlet manifold.... Happy days.
Attached Files
File Type: pdf 2024-04-13 SV650 purge valve.pdf (86.9 KB, 0 views)
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2016 SV650 AL7

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Last edited by SV650rules; 13-04-24 at 03:38 PM.
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