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I can re-bush H4's using the correct JC stepped reamers at a cost of £35 per pair. I supply the bushes in on the price.

Contact me if interested.

M

A little agricultural, but my set up does have a pilot to line them up spot on, you can do them with a hand drill with this if you wanted to. It also includes a depth stop.

Have you done any H4 carbs spider?

The really good thing about this thread is that it has shown that all those capable of doing this accurate job have done it a slightly different way. And all achieved the same result. Rebushed, line bored air-tight spindles and rebuilt carb bodies.

Good instructive thread.........

Spider wrote: ↑Sat Mar 04, 2023 8:03 pm A little agricultural, but my set up does have a pilot to line them up spot on, you can do them with a hand drill with this if you wanted to. It also includes a depth stop.

Agricultural? looks pretty good to me!

Moving on a step with this thread in mind..... Replacing the butterfly absolutely centrally as possible within the body tube is most important too, for obvious reasons. Always mark the body to match the spindle to match the butterfly. A small scratch mark or felt pen is a good idea.

After rebushing or O ringing, insert the butterfly THE CORRECT WAY ROUND according to the chamfered edges of course while roughly aligning the screw holes in the spindle and butterfly. Insert the screws but leave them loose enough to allow the butterfly to centre itself (or with a bit of help from your dainty fingers). Open and close the spindle and butterfly and it will centre itself within the opening. Nip up the screws and look into the opening from both ends up at a bright light or window. Adjust the butterfly position in the spindle until the best position where there is the least amount of light on show That is the best position for the butterfly. Now it's time to lock down the screws

If you closed the slots just sufficient to remove them, they'll be fine to use again. No need to open them like split pins....

timmy201 wrote: ↑Sun Mar 05, 2023 3:14 am Have you done any H4 carbs spider?

Sorry Tim, I only just saw your post now.

No, I haven't done them. Do the have the same or similar bush arrangement as the HS4 ?

Spider wrote: ↑Fri Mar 17, 2023 6:50 pm

timmy201 wrote: ↑Sun Mar 05, 2023 3:14 am Have you done any H4 carbs spider?

Sorry Tim, I only just saw your post now.

No, I haven't done them. Do the have the same or similar bush arrangement as the HS4 ?

I haven’t changed both myself so I’m not 100% sure. I bought a rebuild kit for my H4’s but the bushes are “Teflon lined” and are a loose fit on the spindles and seem to have scratched badly from me just test fitting them. They might tighten up during fitting but I don’t see how they can be teamed to size as it’ll remove the soft inner coating

https://sucarb.co.uk/technical-h-type-c ... nd-brushes

timmy201 wrote: ↑Fri Mar 17, 2023 9:18 pm
,,,,,, but I don’t see how they can be reamed to size as it’ll remove the soft inner coating

Ah, Just to clarify what's going on with the reamer etc, as least on the HS Carbs. Originally, the bodies had no bush, the spindle ran direct in the alloy casting. When that wears, the alloy body is reamed to the OD of the new bush and these are pressed in. They are (or should be) on size when fitted, ready for the new shaft.

The past 5 or 6 years, I have been machining O Ring Grooves in the shaft, such that when the O Ring is fitted, they are flush against the side if the body with only light friction. On assembly, I give the bushes a greasing with some light (instrument) grease. I did this originally to dust proof the carb, but I've found that as a side benefit, the grease remains in place, the shafts and bushings wear so much slower.

Spider wrote: ↑Sat Mar 18, 2023 6:56 am The past 5 or 6 years, I have been machining O Ring Grooves in the shaft, such that when the O Ring is fitted, they are flush against the side if the body with only light friction. On assembly, I give the bushes a greasing with some light (instrument) grease. I did this originally to dust proof the carb, but I've found that as a side benefit, the grease remains in place, the shafts and bushings wear so much slower.

I've received some emails and pms on this.

Here's one that I O Ringed, not the best angles I'm sorry;-

I am another in favour of O rings especially in 90% of cases where it is clearly the spindle that is slightly worn. I differ very slightly in that I situate the O ring on the spindle so that each end seats half way into body. Same meat, different gravy as they say

Hi Mark. I need a pair of H4 bodies re-bushing.
I’ve sent you a PM
Thanks.

mk1 wrote: ↑Fri Mar 03, 2023 4:00 pm I can re-bush H4's using the correct JC stepped reamers at a cost of £35 per pair. I supply the bushes in on the price.

Contact me if interested.

M