Fuel valve

[TPR]

hi all

I am fitting a Suzuki GT 380 fuel tank but the single fuel tap got in the way when fitting . I have this tap which fits, but I'm not sure if it has a vacuum outlet? the bay seller said that it was for an XS 650?

Also, if it isn't the vacuum type, how will the bike run without it?

many thanks

 

[gggGary]

That one is not vacuum. You manually select on - off - reserve each time you start or stop the engine.
looks like hole spacing is close on that petcock.
1977 and earlier non vacuum fuel tanks 42mm bolt centers
1978 to 1984 vacuum type fuel tanks, either one or two petcocks, 46mm bolt spacing.

 

[TPR]

That one is not vacuum. You manually select on - off - reserve each time you start or stop the engine.
looks like hole spacing is close on that petcock.
1977 and earlier non vacuum fuel tanks 42mm bolt centers
1978 to 1984 vacuum type fuel tanks, either one or two petcocks, 46mm bolt spacing.

Thanks. How will the bike run with this type of tap?

 

[TPR]

That one is not vacuum. You manually select on - off - reserve each time you start or stop the engine.
looks like hole spacing is close on that petcock.
1977 and earlier non vacuum fuel tanks 42mm bolt centers
1978 to 1984 vacuum type fuel tanks, either one or two petcocks, 46mm bolt spacing.

addition- the holes line up and it goes on well.

 

[gggGary]

Thanks. How will the bike run with this type of tap?

Not vacuum/automatic. You manually select on - off or reserve each time you start or stop the engine.
If you don't turn it off the bike will give you a (nasty) reminder.

 

[gggGary]

You will need to cap any existing vacuum tap line(s)
Like a nun with a ruler the petcock will quickly teach you to learn/remember the drill.

 

[TPR]

Cheers for that. I'm pretty new to old bikes as you might have guessed!

 

[toglhot]

More info on the tap for you, lest you find out the hard way: Make sure the tap is turned off every time you kill the engine. Carburetor needles do stick on ocassion, resulting in free flowing fuel through the carburetor and into the sump, thus contaminating the engine oil. The oil will thin and as a result lubrication of engine parts will be compromised.
If you don't turn the taps on when you start the bike, you will get about 200metres down the road and the engine will stop.

 

[toglhot]

A nun with a ruler, geez that brings back memories. Some of the nuns I ran into as a kid used rulers, others had much better weapons: Straps, canes, coat hangers, ping pong bats, one had a length,of wood and they wielded them with great delight. Horrid things nuns, but that's what you get when you deprive yourself of a life and start believing in mythical fairy stories.

 

[5twins]

Yamaha still makes and sells very nice vacuum caps and the retaining clips for them. You want and need the retaining clips because the caps will blow off if the bike backfires through the carbs, which these old girls are prone to doing occasionally, lol. They fit well and last a long, long time. They're not that expensive so I highly recommend using them. I tried automotive vacuum caps but they don't last very long, splitting within a couple months.

 

[jetmechmarty]

Yamaha still makes and sells very nice vacuum caps and the retaining clips for them. You want and need the retaining clips because the caps will blow off if the bike backfires through the carbs, which these old girls are prone to doing occasionally, lol. They fit well and last a long, long time. They're not that expensive so I highly recommend using them. I tried automotive vacuum caps but they don't last very long, splitting within a couple months.

View attachment 265147

 

[gggGary]

These dorman caps last "forever" 4 of each size in the package. And yes you MUST use some sort of clip or they WILL sky launch. They also make nice little bolt end covers.

https://www.amazon.com/Dorman-Help-...hvlocphy=&hvtargid=pla-4583726553900040&psc=1

 

[Jim]

...and bleed nipples and zerks too.

 

[TPR]

Yamaha still makes and sells very nice vacuum caps and the retaining clips for them. You want and need the retaining clips because the caps will blow off if the bike backfires through the carbs, which these old girls are prone to doing occasionally, lol. They fit well and last a long, long time. They're not that expensive so I highly recommend using them. I tried automotive vacuum caps but they don't last very long, splitting within a couple months.

View attachment 265147

that's handy, thanks