20 replies to this topic

[Boycie]

Hi all,

The float chamber is flooding on my pre-waxstat HS4 carb. It is an earlier chamber without the extra fuel line that diverts fuel to the floor.

Hence, it just pee's fuel out through the top of the float chamber, and on to the scorchio exhaust fanimold

Anyway, I took it all apart, fitted another needle valve with it's brass housing and another float. It worked for a few miles then flooded again. Each time I take it apart, it's all clean with no cr4p anywhere.

Is there anyhting other than the needle valve that could cause this to happen? It works perfectly when I have it apart and blow through it!

[Dan]

What pump are you using?

Please don't try to find ways around the swear filter.

[Boycie]

Just the standard mechanical pump, Dan. It was fine before it's 3-month rest!

[benb12]

Hmm, did you fit a new washer as well?

[Ethel]

Did you adjust the float? Is the float holed? is the float pivot worn? If the valve spring is weak the float may be too heavy for it & not be gapped properly.

[Boycie]

Now, that is a good question Ben! I didn't because none came out. I've looked on the exploded diagrams and it doesn't show a washer, however I've noticed the replacement valves from Minispares come with a rubber 'o' ring.

Ethel, there is no adjustment, the float seems fine and is not taking in fuel, the pivot is also as you'd expect.

I think I'll just order all new bits and go from there, it's so bloomin' simple!

Edited by Boycie, 26 January 2010 - 05:25 PM.

[bmcecosse]

The float bowl has to be vertical - is it ?

[dklawson]

The later all plastic floats don't have adjustable metal arms to let you set the float level. They depend entirely on the thickness of that spacer/washer to not only seal the brass body to the carb but also to set the float height. It's also unfortunate that an o-ring really won't work here. When you start to tighten the valve body to the bowl lid, the o-ring will just get squished out of place. The original washers were often made of fiberboard. However, I've seen these washers made of brass, copper, and/or aluminum. If you are lucky your local parts store may have some of a suitable size and thickness for you to buy a few and get the float adjusted.

[benb12]

The last needle valve I bought (from Minispares) came with a couple of flat rubber washers.

[liirge]

What about installing one of those updated valves that use a ball bearing type system?

[bmcecosse]

They are indeed 'supposed' to be better. But my mate fitted them on his MGB - and has had nothing but trouble with them........

[dklawson]

What about installing one of those updated valves that use a ball bearing type system?

Those would be "Grose Jets". You either love them or hate them.

Grose Jets had a good reputation when first introduced... 25+ years ago. However, the company that now owns the product doesn't appear to be doing as good a job making them. I had them on the Mini and the GT6. I removed them from both and now use Viton tipped "regular" float valves because they either leaked or stuck closed (their choice depending on the phase of the moon). Some have speculated that the real issue with the current Grose Jet product is that the steel balls are coated with a Cosmoline type rust protectant that must be washed off before use. I know of people who swear that sealing issues do not occur if you clean the Grose Jet (prior to installation) by soaking it in carb cleaner. This information came to me too late for me to ever consider trying them again.

[liirge]

hmm, interesting stuff there DK, i suppose it goes with everything though in terms of its only as good as the production quality

[benb12]

Have you sorted this Boycie?

I'm in the hate camp for the ball bearing valves. I bought one and it flooded worse than it did with the knackered needle valve which had very deep ridge worn around it.

[Boycie]

Nope not sorted this yet!! I've held fire on buying the bits too, however I was about to buy a 'grose'-type valve, new float etc etc. Interesting you say about the chamber being vertical bmcecosse- the problem started once a new inlet had been fitted.. would imagine it should be ok though, I'll check when it gets light tommorrow!

I'm still concerned that I have no washer or 'o' ring between the brass valve body and the float chamber lid.. it's never had one though and this is the first time I've experienced flooding issues.