[Roadsters] How to warm up a Roadster?

[James Fogg]

> To choke or not to choke, that is the question.
>
> Once and for all I'm trying to figure out the best way to
> start off without fouling the plugs or causing gasket
> problems due to metal components warming up (and therefore
> expanding) at different rates.

You don't have much control over, or contribution to, expansion. The
only thing you can do wrong is run too lean, which will cause a higher
cylinder temp. I use full choke for cold starts and I open the choke
slowly until the engine starts to stumble (too lean) and then close it
up a bit. I test the choke setting a few times while it warms up. If
you're really worried about a too-fast warm-up then you want to be a bit
generous with the choke. Plugs are cheap and the kind of fouling they
experience with choking will burn off after a bit of driving. True
fouling is best done by oil contamination (worn rings, or worse).

If you open the choke fully as soon as it's running and use the throttle
to keep it running you are running lean (hot). The choke isn't an on/off
proposition. It's a variable setting that will get closer to full open
as the engine warms.

> I've always choked it as little as possible, for the least
> amount of time as possible. If it's warm out then that's not
> too much of a problem. When it's colder out it becomes more
> of an issue. The hand throttle really helps with this. I try
> not to take off until I see a bump on the temp gauge.


That's a good policy.