TR4/4A Two 4As--why so different?

[KVH]

I'm lucky. I own two incredible 4As.

Both have HS6, SU Carbs.

Both cars run great.

But one starts right up from dead cold and just idles as smooth as can be. I don't even need to choke it. I've owned it two years and haven't tuned it once. Maybe that's why it's so fine!

My other one is static timed, perfectly, and the point gap is right on. But it requires a good pull of the choke to start, and requires sort of a "choke on choke off" approach until the car warms up, then it runs great.

I have two questions: First, why are the two cars so different on start up? The one car so darn smooth. It's seriously like new Buick.

Second, the one that runs so smooth has some kind of special camshaft. Does that mean that I can't time and adjust points per the manual? I checked the point gap and it was close to .018. I didn't dare touch it.

 

[RJS]

In your part of the world, I wouldn't imagine you need very much choke, if any. But, my guess is that the one which does not need the choke probably has the carbs adjusted a bit richer than the other.

Bob

 

[Geo Hahn]

Even in hot weather (100°+) mine both require a bit of choke to start a 'cold' engine. If they didn't, I would suspect some adjustment was in order.

 

[3798j]

Even in hot weather (100°+) mine both require a bit of choke to start a 'cold' engine. If they didn't, I would suspect some adjustment was in order.

In agreement. Mine needs enrichment when starting from cold - even on the hottest of summer days.

 

[startech47]

Float level?