HS4 carb help

Post by **RogerRust** » Sun Jul 30, 2006 5:57 pm

I'm thinking of buying one on ebay, what are the 4 conenections on the carb? Please see picture:

Fuel pipe, vacuum advance and breather but which is which and what is the other one?

Post by **Welung666** » Sun Jul 30, 2006 6:04 pm

I think it's...

Post by **RogerRust** » Sun Jul 30, 2006 6:07 pm

so I just block off the fuel return?

Post by **Welung666** » Sun Jul 30, 2006 6:09 pm

Most people fit a small piece of fuel pipe with a bolt in the end and jubilee clip them in to stop any leaks

Post by **chrisd87** » Sun Jul 30, 2006 9:21 pm

If the float chamber is the same size as the HS2's then you could swap one over that only has the inlet. I think those 'double' ones are supposed to go on a car with twin carbs as one supplies the 2nd carb.

Post by **aupickup** » Sun Jul 30, 2006 9:29 pm

i think you will find on these carbs it is a fuel overflow pipe.
actually no fuel will pump out of it.

Post by **Welung666** » Sun Jul 30, 2006 9:30 pm

Surely then if it's blocked off it should be ok as it is.

Post by **aupickup** » Sun Jul 30, 2006 9:40 pm

mine is left open witha small tube and works fine

Post by **bmcecosse** » Sun Jul 30, 2006 10:24 pm

It's an overflow/breather for the float chamber - DO NOT block it off!
But this is quite an old HS4 carb - not nearly as good as the later HIF (Horizontal Integral Float) 38mm carb. With the early carb you need to be SURE the float chamber is vertical when bolted on the engine. The HIF carb can work over a range of angles - and it doesn't splutter/overflow/ cut out on round-abouts. However - if the price is right - the HS4 will work ok - provided the float chamber is vertical.

Post by **Alec** » Mon Jul 31, 2006 8:08 am

Hello RR,

if you do win it, you might consider getting rid of the waxstat jet for a basic one, it may also have the over run valve in the butterfly, another complication that can be more trouble than it's worth.
The float looks at the right angle but changing the angle is simple, there are a variety of adaptors that fit between the chamber and the body to set the angle depending on the manifold.

Alec

Post by **Packedup** » Mon Jul 31, 2006 10:34 am

Alec wrote:Hello RR,

if you do win it, you might consider getting rid of the waxstat jet for a basic one,

True, it only costs 2p!

http://www.nireland.com/gd.triumph/waxstats.htm

Post by **Alec** » Mon Jul 31, 2006 12:50 pm

Hello P U,

and they say the Scots are mean!

Alec

Post by **bmcecosse** » Mon Jul 31, 2006 1:19 pm

Excellent tip - and yes, we are mean - could steel washers not be used instead of wasting 2 P ??

Ratbag · Post by **Ratbag** » Mon Jul 31, 2006 2:48 pm

Alec wrote:Hello RR,

if you do win it, you might consider getting rid of the waxstat jet for a basic one, it may also have the over run valve in the butterfly, another complication that can be more trouble than it's worth.
The float looks at the right angle but changing the angle is simple, there are a variety of adaptors that fit between the chamber and the body to set the angle depending on the manifold.

Alec

To anyone that wants rid of the overrun valve in the butterfly for no cost...
disassemble the poppet valve, remove the spring and insert the poppet from the other side, rivet over the stem with a ball pein hammer. Sorted!

Post by **Packedup** » Mon Jul 31, 2006 4:06 pm

bmcecosse wrote:Excellent tip - and yes, we are mean - could steel washers not be used instead of wasting 2 P ??

Steel washers cost more than a penny each where I buy them...

Just be thankful you're not dealing with twin waxstats - Doubles the cost!

Actually, other than being tight, I suppose the 2p mod means everythnig still looks original, to those who are quite so obsessed with such things

Post by **Onne** » Mon Jul 31, 2006 4:50 pm

apart from having a HS4 of course!

:D