tank vacum pipe

[trevair]

hi all
what is the main purpose of the tank pipe and how critical is it that it doesent leak the pipe is so small
the reason i ask i have built up different sizes of pipe to usethe original smal id bore pipe
regards trev

[kanonkopdrinker]

Trev,

Could you remind us what machine you are enquiring about, please?

David

[trevair]

Commander

[trevair]

Am i right in thinking the vacum from the engine open the fuel tap how technical would that be

[johnbirchjar]

Yep,that's what it does,(and b******d ethanol just loves the rubber diaframs in the fuel taps ,)I did away with that system and converted to a gravity
fed system on my Classic.J.B.

[trevair]

Hi john what did that entail new fuel tap or converted and if so how please
Trev

[Anthony Duffield]

I think but cant be sure that the vacuum operated fuel taps on the Commanders is from Yamaha, note that it has a reserve position. I have not had any issues with ethanol having owned my bike for many years.

I have previously changed the vacuum pipe, ANL had and might still have them in stock.

You can change to a different system if you wish, I like to keep things as original as possible, if it ain't broke don't fix it!

[Interpol2471]

I replace the old plastic tubes with silicon vacuum hose which works really well and available in nice black colour

[johnbirchjar]

Hi Trev,
If memory serves(it was about 10 years ago )I removed the spring that operated the diafram in the original tap(so it was permanently "on"), then put a bog standard on/off tap between the original tap and the carbs,I used a bog standard on/off tap so I could turn off the fuel whenever I had to remove the fuel tank.
All three positions still worked on the original tap(even the reserve )SVF,J.B.

[trevair]

Chers john
Have ordered service kit for tap and have found vacum pipe with 90 degree angles same as off austin healy car
Happy dsys the start up is iminent
Trev

[Ian]

That pipe is identical to an A-series Mini engine. Mine went to jelly and wouldn't operate the diaphragm so no start.

New pipe, started first time.
Bloody effinol!

[trevair]

There should be no petrol in the part that works the operer otherwise it woul fill withe petrol and seep down tube the tap kit ive bought is genuine
Trev