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BLOCKED FUEL TANK VENT

Posted: Mon Oct 21, 2019 6:48 pm
by WRONG/SIDE
HI
Have been repairing a 2014 Ct[crashed] which i imported from Australia into New Zealand a few years ago
The steel overflow pipe just under the fuel tank cap -which ? should exit the tank base and drain is blocked solid
And i mean not just sometime blocking it-BUT appears to be solid steel.appears that when assembled the smaller steel pipe has been melted together when it was welded on exit of tank base
Has anyone got an exploded diagram of the inside of the fuel tank
I need to sort a plan to fix? but need to know how that pipe is attached and routed
i don't want to risk running a drill bit up the hole -probably track off or worse still break off due to hardest of weld
Any ideas? Please

This bike has low kms[3000] but cant understand how fuel didn't leak out of fuller cap when tank was full-[maybe it did-unknown last owner] and fill his/her crunch with expanded fuel or leak all over tank when sitting and heated up--worse still catch fire

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 1:43 am
by Tomcatfixer
Buy a replacement tank. Time is money and this sounds like an expensive project with all of the time you'll have invested.

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 9:09 am
by Lokiboy
The overflow is nice but not really needed. Just watch the level of gas you put in and ride on.

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 9:46 am
by Msblu79
Not sure about 2014's but the fuel cap is probably vented instead of the tank would be my guess. :)

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 10:32 am
by rivers
Lokiboy wrote:
Tue Oct 22, 2019 9:09 am
The overflow is nice but not really needed. Just watch the level of gas you put in and ride on.
You may not need the tank vent via the pipe but you do need a vent or the motor won't run for long. Air has to get in and replace the fuel being used up. If it can't it'll eventually pull a vacuum on the tank and fuel will no longer flow to the motor and shut down. If the pipe is totally blocked you'll know it when it quits running and you loosen the gas cap you'll get a whoosh sound of air rushing into the tank.

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 11:26 am
by Lofty
rivers wrote:
Tue Oct 22, 2019 10:32 am
You may not need the tank vent via the pipe but you do need a vent or the motor won't run for long. Air has to get in and replace the fuel being used up. If it can't it'll eventually pull a vacuum on the tank and fuel will no longer flow to the motor and shut down.

If the pipe is totally blocked you'll know it when it quits running and you loosen the gas cap you'll get a whoosh sound of air rushing into the tank.
Provided the cap on the fuel tank is vented and functioning correctly, the vehicle should not experience any vacuum-related running failure. I doubt the overflow pipe does, or should, draw air in from the exposed hose end that is positioned just above ground, near the exhaust. That's the job of a vented fuel fill cap.

Is is possible that an unblocked overflow pipe could serve as a proxy for a non-venting fuel fill cap? Yes, but that's hardly preferable. Consider the detritus that could be sucked in as a result of it performing in a manner that it wasn't intended to serve.

The OP doesn't mention any fuel starvation issues, so the matter of potentially living with a blocked fuel overflow pipe is indeed possible, as Lokiboy mentions.

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 6:20 pm
by WRONG/SIDE
Lokiboy wrote:
Tue Oct 22, 2019 9:09 am
The overflow is nice but not really needed. Just watch the level of gas you put in and ride on.
Yes understand i can get by without it??-guess i will fit a larger spare fuel can-lol

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 6:22 pm
by WRONG/SIDE
Msblu79 wrote:
Tue Oct 22, 2019 9:46 am
Not sure about 2014's but the fuel cap is probably vented instead of the tank would be my guess. :)
yes cap is vented and working-but vent only works one way-it sucks-so any pressure built up by expanding fuel in tank on hot day will have the fuel looking for an escape-

Re: BLOCKED FUEL TANK VENT

Posted: Tue Oct 22, 2019 7:43 pm
by WRONG/SIDE
Tomcatfixer wrote:
Tue Oct 22, 2019 1:43 am
Buy a replacement tank. Time is money and this sounds like an expensive project with all of the time you'll have invested.
HA HA HA -saving the money for the next issue