Twin H4 jet seals

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mk1coopers
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Twin H4 jet seals

Post by mk1coopers »

I've just put my twin H4's back on the car after they have been off for the last 10 months or so during the engine rebuild, last time they went back on after sitting for a while they started to leak around the jet seals / lower rubber float chamber area, so a new seal kit was fitted, this time only one of them has started to leak.

I know Burlen do an uprated 'Superdry' kit which fits with new jet bearings ect, and I know that the current type of cork seals need to be soaked in oil for 24 hours plus to get them to seal ( I have new kits here) so does anyone have any further tips on getting these carbs to seal in this area whilst they are off.
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Re: Twin H4 jet seals

Post by Nick W »

Hi
I fitted Viton O ring seals instead of the cork ones , which seemed to break up a little when fitted!.....Nick . The cork ones that is!
Up North in Sheffield
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Re: Twin H4 jet seals

Post by mk1coopers »

Thanks Nick, I've already got viton set on order, the cork seals are soaking in damper oil, hopefully this will sort it :)
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Re: Twin H4 jet seals

Post by 970s »

Hi, may I know what type of O ring does the Superdry kit provide? Same cork type or different material? Had the same leaking problem!
Thx!

Al
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Re: Twin H4 jet seals

Post by mk1coopers »

Hi Al

This is the link to the seals, I'm going to try a combination of the viton O rings and a soaked cork seal first, if I still have a problem the carbs may have to come apart again (the Superdry kit has different bearings ect)

http://sucarb.co.uk/h-type-superdry-jet ... l-kit.html
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Re: Twin H4 jet seals

Post by rich@minispares.com »

I recently had a right head scratcher problem with a Burlen supplied item.....


went to move my dads Derby Bentley (yah yah yah!), it hadn't moved for six months or so, turned it all on and the pump (a double end su) wasn't pumping much (normally you would expect the excited clatter as it filled the pipes), pressed the float depressors on the carbs, no pump action.

spent ages taking the points out the pumps and cleaning them - no joy

all the fuel pipes are metal and held together with very fragile nuts, so its absolutely last resort to try and undo them, so I left the pump alone and decided to take the tops of the carbs and 'manual fill' them (in fact, top tip, if you ever see a old Rolls or Bentley with a jubilee clip around the fuel pump nuts, you know that the nut has cracked and wont tighten up..... :lol: )

again, its a bit of a chew as the overflows vent into tiny soldered copper pipes, so its not as easy as a mini, once I got the tops off, both carbs where bone dry...

the fault? - the new Burlen float needles had glued themselves shut so hard that even the psi pressure of a double pumper wouldn't dislodge them - really strange, they must have stuck ever so fast the last time the floats where full and before the fuel evaporated. I had to yank them out with a tiny pair of pliers

normally they stick open, but the fuel rushing through them will clean the gum away and they will shut ok

it took hours to put it all back together :lol:
should you wish, you can contact me on rich@minispares.com

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Re: Twin H4 jet seals

Post by mk1 »

The most important thing when re assembling H4's is to make sure everything is BONE DRY apart from the ring seal which should be soaked in oil, although I never do it more than 5 minutes or so.

Once the float chamber bottom seals start rotating, you know that they will be leaking before too long.

Also a good idea to make sure you have the correct selection of washers holding the seals in place & under tension.
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Re: Twin H4 jet seals

Post by mk1coopers »

Thanks Mark, I'll give it a go when all the new parts turn up, the plan is to then reconnect them to the fuel supply before bolting them to the car (sat at the right angle) and see what I get, if they stay dry I'll put them back on, if not then it's plan B :)
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