Vacuum fuel tap

[Skub]

A vacuum operated fuel tap should not flow petrol unless the engine is running.

Right?

[Druid]

Right

unless it's on Prime

[Skub]

As I suspected then,the vacuum is borked.

[Le_Fromage_Grande]

The diaphragm has got a hole in it, or the spring is missing

[iansoady]

I think they're terrible things - a (bad) solution looking for a problem. Manual taps are more reliable and only require a moment's attention.

[Druid]

I think they're terrible things - a (bad) solution looking for a problem. Manual taps are more reliable and only require a moment's attention.

Yep, and fifty year old ones are even more troublesome. I gave up trying to fix the vacuum tap on my GS750 and replaced it with a manual one

[JackyJoll]

I never fancied a vacuum tap on a kickstart-only bike, even when the tap is working properly.

[Skub]

Whatever I decide to do,the fuel tap will at least have an off position,at least I'll be reasonably sure the fuel is stopped when it should be. I needed to change the fuel lines today and that was a right twunt when I couldn't turn off the flow.

I might be in danger of smelling like a real motorcyclist today.

[JackyJoll]

Black rubber fuel injection hose is the stuff.

[Bustaspoke]

In my eye's Vacuum fuel taps are the work of the devil. It will be the first thing to swap if I ever get a old bike with a Vacuum tap fitted

[mangocrazy]

Is there not a manual fuel tap available from Kawasakis of the era that you could replace the accursed vac tap with? I know that when fitting YPVS carbs to an LC that the vacuum tap inlet on the carb(s) has to be blanked off, so I guess that might also need to be done on your H1. If you don't the carburation will be all over the shop.

[mangocrazy]

And if you're looking for fuel hose, clear Ariete hose (purple, but clear) is the stuff to use. PJME sell it, as do a number of other places. Doesn't crack, sweat or leak and does the job.

[Le_Fromage_Grande]

Is there not a manual fuel tap available from Kawasakis of the era that you could replace the accursed vac tap with? I know that when fitting YPVS carbs to an LC that the vacuum tap inlet on the carb(s) has to be blanked off, so I guess that might also need to be done on your H1. If you don't the carburation will be all over the shop.

Why would you put YPVS carbs on an LC, they're the same carbs as an LC apart from the vacuum take off for the tap.

[mangocrazy]

Is there not a manual fuel tap available from Kawasakis of the era that you could replace the accursed vac tap with? I know that when fitting YPVS carbs to an LC that the vacuum tap inlet on the carb(s) has to be blanked off, so I guess that might also need to be done on your H1. If you don't the carburation will be all over the shop.

Why would you put YPVS carbs on an LC, they're the same carbs as an LC apart from the vacuum take off for the tap.

I was advised by no less than Gerry Pell to use 31K carbs on my 4L0. I didn't argue... After a dyno session on Dave Muttsnuts's dyno, the carburation is pretty much as good as it gets. I know they are supposed to be the same carb, but that's not the opinion of a lot people who know. I'm just very happy that the LC is now running better than it ever has in 43 years...

[Le_Fromage_Grande]

They're both VM26s, slides and needles are different, and power valves are crisper than LCs, especially pre tie bar 350 LCs.

[mangocrazy]

In the late 80s I bought an F1 YPVS off a mate (ostensibly) for my girlfriend to ride. The carburation on that was absolutely perfect, crisp as you like. I often took that to work in preference to my VFR. Should never have sold it...

[Le_Fromage_Grande]

I had an 84 YPVS, it was lovely and crisp, I had a 1980 350 LC that wasn't, the 1981 250 LC I had was also good, the price is race 250 I had was amazing, no idea who tuned it, but it went like stink and was lovely and smooth, it also handled really well, it looked standard, but wasn't.