Carb mounting.

Steve C

Hi, p62000tc HS8 carbs, i am hoping to get my refurbished carbs back soon and have been cleaning up the manifold and other bits and pieces, question as follows, when i removed the carbs i noticed that the top mounting bolts ( mounting plate to inlet manifold ) had a flexible rubber bush fitted between the plate and manifold, but there was no rubber bush on the lower mounting bolt., i can find no reference to this rubber bush in the parts book or any mention of it on the forum. I have had a trial fitting of the adaptor plate, and it will fit nicely with or with out the top bush.

any help on this would be great.
Regards Steve.
There should be no bits of rubber there. Somebody has had weird thoughts and tried to fix something that isn't broken.

Vern, thanks for the quick answer, pity I didnt ask the question before spending a couple of hours trying to find the part number for something that shouldnt be there.

Regards Steve.
As Vern said they shouldn't be there. The TC has a rather unusual setup. There's a large O ring on the throat of the carb going into the manifold. The carbs 'float' on the O ring and the weight of the carbs are supported by that spring that sits between the two carbs above the throttle shaft. Once you have the carbs and airbox assembled you adjust the tension on the spring until the gap between the carb's back plate and the face of the manifold are parallel. That way the carbs have their own suspension system that isolates them from the engine's vibrations and harmonics (apparently a problem during testing).

I hope that makes sense? If not I'll grab some photos and share when I get a moment.
Thanks for that, Yes i understand how the carbs are supposed to float, and the gap being controlled by the spring, what was confusing was the 2 rubber spacers, cant work out why they were there in the first place, the gap was parallel with them in place. any way they are now in the bin.
Can,t wait to get the carbs back.
Regards Steve.
Some years back I did experiment with leaving the suspension assembly off of Bruiser as pancake filters were fitted & l did something that suggested the idea to me, l can't remember what. Anyway a trip to The Cranleigh Lions show in Surrey was carried out & the return journey was interrupted by rough running. A quick inspection revealed a loose carb assembly which was tightened up but it was soon apparent that the suspension assembly was an essential component. :LOL: