Carb Throttle Bushes

[Neil W]

A

[jbuckl]

The bush shown seems like the correct item.

The Kit from zenith includes the seals, seal caps & spindles, but no bushes iirc.

Is there any corresponding wear on the spindles?

[NickA]

my kit from Burlen http://zenithcarb.co.uk/carbspec/car...pares/id/4103/ came with the bushes complete with seals. I don't remember them looking like the 4th picture. Maybe I just got the seals but they came contained in a small brass surround that was tapped into the carb body

[jbuckl]

Neil, you are correct, the spindle bushes don't come in the kits.

If you really need to change the bushes, the important things to do are:-

1, Don't attempt if the fit is too tight, adjust the fit first otherwise the castings may crack / distort. (better to have a light fit say 6 microns/0.006mm & use red loctite to secure)

2, If necessary after fitting, use a long series reamer to size the bushes so the reamer passes through both the bushes in one pass.

3, Use new spindles discs and screws, ensuring that the discs are firmly shut / centralised with a throttle lever attached before any tightening of the screws begins. (this prevents an excessively high airflow past the disc at idle)

It is pretty unusual to have a requirement to change the bushes.....the wear is normally in the spindles and seals only.
Usually new spindles and seals fix the air leakage.

The bush wear, if excessive, may have been caused by high loads from the linkage being mal-adjusted or something having been bent?

[KOY 23]

Why not have them expertly overhauled by the Gauge Shop?

[stag157.7]

Thanks for the above –

Spoke to Burlen’s regarding my Carbs and they were really helpful and went over the procedure for changing the throttle bushes which they confirmed was probably the problem with my carbs when I described the symptoms – they said as part of their carb refurbishment service they often change them.
They charge approx £250 per Carb to fully overhaul & £75 to re bush a carb when required but time scale presently is 16 weeks.

They can supply bushes under AUD 3080, these retail for £2.10 each + vat but getting the re bushed locally could be more cost effective if that was all that is required, which was a good of them .



Burlen’s Teflon Coated Steel Throttle Spindle Bushes, are 5/16in Internal Diameter ( approx. 8.mm as per spindle ) you Ream the original throttle bushes to 9.5mm and insert.
They also said to be careful not to go through into the bore of the carburetor, as the bushes need something to push against.

Their Bushes are different to the one’s Paddock’s Supply as they are sleeves not the complete Bush.

Here is also another temp fix which is to fit seals externally

those bushes are for S.U Carbs
do not attempt to fit on strombergs the bush mentioned is correct as in fist post.
they have to pressed in and out.
very odd to leak with new neoprene seals

alan

[KOY 23]

A course at the Sexual Health Clinic should sort that out.

[jbuckl]

If teflon bushes are used, its normally not recommended to ream them.

If they need any post fitting sizing, the best way to 'size' teflon / plastic bushes is to use a ball bearing to 'burnish' to size.

If there is any 'stiction' with the new shafts, it does need to be sorted or the idle will be variable.