I have searched the web and the forums on this topic and I haven't found a clear answer, so if anyone could help out that would be great.

I'm wondering how I should properly start up and warm up my carbureted FB? And also how I should start it and warm it up in cold weather (like below freezing). I've read numerous opinions and some say that letting it warm up before driving is good, and others say it is bad. I would like a final verdict on this please. Thanks for any help.

 

i will push the gas pedal once or twice, and start it, then pull the choke out so it's idling @1500 or so.

i start driving right away, but i do drive gently until its warmed up. if its really really cold i might let it run for 30 seconds - 1 minute.

letting it warm up longer won't hurt anything, it just wastes gas.

 

Down here in Georgia, it doesn't get cold very often.

But when it does, we just sweet talk the Nikki.

It works every time (clic the pic for the vid; don't forget a prayer to the Rotary Gods when she starts).

 

It was hard to see, but were you trying to start it without having the choke out? And no pumping the accelerator either?

 

Exactly. Anything more that that will flood it and you're done for the day. Ask me how I know.

 

Paraphrasing the owner's manual:

1) Shift to neutral. Hold clutch in while starting.
2) Key to "on".
3) Pull choke fully. **** will stay out if engine is cold enough to need choke.
4) Key to "start"; release when engine catches.
5) Choke to half after approx 15 seconds. (note; if working properly, it will do this automatically between 15-60 seconds)
6) Hold 2000 RPMS via choke adjustment.
7) After two minutes, return choke fully (note; if working properly, it will do this automatically based on engine temp)

 

So what temperature range does it have to be outside to be mindful of flooding with the choke out?

 

There are two factors.

First, the flooding problem is related to the age of the engine. When old 12As are cold, their compression isn't what it would be in a new engine with fully functioning apex and side seals (like the ones they talk about in the owner's manual). The low compression cold start condition makes the engine prone to flooding before enough gas vapor can be created to establish that initial combustion.

You can see this phenomenon in the video. Notice how when I first engaged the starter it fired up for a moment, then quick firing? The rotors had sucked too much liquid fuel into the combustion chambers for the spark to ignite and created a brief flooding condition.

Turning it over WITHOUT CHOKE OR ACCELERATOR helps to clear this initial burst of fuel and get those old cold engine parts loosened up so they can start to establish enough compression to vaporize gas and start to fire. Touch the gas or choke at this point and you may have to continue cranking for quite awhile longer, if you haven't flooded it out completely.

The second factor is what we mean by cold. There's Ohio cold, which on an average winter day is similar to what you see in the video.

And then there's California cold, like DD and J9 are talking about, where you put on a light jacket, give the accelerator a pump, pull the choke and even a 175,000 mile 12A starts right up.

Of course, living in California, DD and J9 have all those smog issues so they probably have freshly rebuilt 12As, which would help considerably.

 

lol, i usually remove the choke, it isn't needed at all. you are right Ray, the only 12A's ive had that were original were SA's, every FB i've ever had was on a junkyard engine that leaked between the housings.

 

Below freezing starts here in Ontario, Canada have been achieved successfully daily by 2 pumps on the gas pedal and a very slight amount of choke before cranking.

This engine is fairly fresh though.

 

Thats the same phenominon (spelling) I'm going through right now...both the 85 and the GLC have developed mild leaks between the plates and housings. Once warmed up it is not an issue, but WTH??? The 81 with its FMOC and busted exhaust stud can sit for months and start right up and go like stink with out a drip

 

The 83-85 models are more prone to develop housing leaks because of the less effective "bee's nest" oil cooler that they have, unlike the other models with the front mounted oil cooler.