TR4/4A TR4-Stromberg throttle shaft play

[Steviemc]

Oh wise ones, a question if I may?

I'm struggling to get my TR4a, fitted with Stromberg carbs, to idle smoothly. Also it stutters at low revs and when on a very light throttle...goes great above 2000rpm.

I noticed my throttle spindles have some play in them, not a huge amount but definitely noticeable. Is there a tolerance for play on these? I'm guessing air might be getting in and messing up the mix when the throttle valve is closed.

Any wisdom or top tips?

 

[Sarastro]

Ideally, the shafts should be a close, smooth, sliding fit. They always wear though, and it can be hard to say how much wear is acceptable. I've never seen a spec for this. A little air leakage probably doesn't affect the running, but it makes it very difficult to set up the mixture correctly.

 

[poolboy]

Go to page 30.....this applies to SU carbs and the early ZS carbs for the TR4's but not the ZS carbs found on the TR250 and TR6 that had rubber bushing seals to prevent leaks and metal wear.

https://mossmotors.com/media/wysiwyg/catalogpdf/t24_catalog_web.pdf

 

[Steviemc]

Go to page 30.....this applies to SU carbs and the early ZS carbs for the TR4's but not the ZS carbs found on the TR250 and TR6 that had rubber bushing seals to prevent leaks and metal wear.

https://mossmotors.com/media/wysiwyg/catalogpdf/t24_catalog_web.pdf

Many thanks, really appreciate the link. Just the info i was after!