Hot Start C-85?

[MAC]

After flying my newly acquired BC12D this evening for an hour or so and shutting down I couldn't get it restarted.
I called the previous owner after I returned home and his procedure was on shutdown he shut off gas for a couple of seconds then the mags. On restart he simply turned gas back on, either closed throttle or 1/8 to 1/4 open and he said it always started on the first prop. He said if you pull the prop through a few times first it floods and then he had to open the throttle quite a bit to get it going.
Any thoughts appreciated, but will read them tomorrow as it is my bedtime.
MAC
I love the way this thing lands.

[AndyDuke]

Re: Hot Start C-85?

MAC

Hot starting will depend on how you shut down. You can either switch off the ignition and increase the throttle to full power which will purge the cylinders of fuel or you can switch off the ignition while leaving the throttle at idle, which effectively primes the cylinders.

In the case of the former, when hot starting I will pull the engine through four blades, set the throttle 1/2 inch open and then start.

In the case of the latter, set the throttle 1/2 inch open and then start.

My 85 will usually start first go with either method. The problem usually occurs when the aircraft has been sat idle for 30-45 minutes, when the engine is just a bit warm. Do you hot start or cold start?

[MAC]

Re: Hot Start C-85?

MAC

Hot starting will depend on how you shut down. You can either switch off the ignition and increase the throttle to full power which will purge the cylinders of fuel or you can switch off the ignition while leaving the throttle at idle, which effectively primes the cylinders.

In the case of the former, when hot starting I will pull the engine through four blades, set the throttle 1/2 inch open and then start.

In the case of the latter, set the throttle 1/2 inch open and then start.

My 85 will usually start first go with either method. The problem usually occurs when the aircraft has been sat idle for 30-45 minutes, when the engine is just a bit warm. Do you hot start or cold start?

Thanks Andy.
As a new owner I have actually only started this engine 3 times though last summer I flew a 65 Continental on a Cub for a few months.
Previous owners prodedure was to just leave throttle closed or only open perhaps 1/8 or 1/4 inch, pull through 3 or 4 times and start and that has worked. It went on the third or forth pull. Saying this, when I shut down previously, I just went to idle and killed the mags. Have never used any prime. The former owner said he never primes unless it is below 30 farenhite or 0 celius. It just sits there and idles at 500 rpm. With 1/4 throttle it is up to 800 or 900 rpm.
I've only had the one hot start and it failed to go.

[alwaysoar]

Re: Hot Start C-85?

One thing is for sure, if you don't get it right, it can drive you crazy.

[AndyDuke]

Re: Hot Start C-85?

MAC

One other thing that I forgot to mention, was that I don't have a primer on my BC12D, so I have to prime by pulling through. This explains why I didn't mention priming in the previous reply.

[flyguy]

Re: Hot Start C-85?

Congratulations on getting an 85. You're going to love the way it climbs!
I can have some problems starting when the engine is hot, if I get careless and forget that it is hot.
When the engine is cool it is 1/4 in., prime, 4 blades, switches on, 1 blade.

I have a steel needle in the carb. and sometime when it is HOT it leaks, so I have to realize that the situation at the intake is always going to be VERY rich under these conditions.
Hot Start: Throttle 1/4 in., switches on, flip it. Do not pull it through any before making ignition hot, it will just load up the cylinders.
If it doesn't fire open the throttle (switches off, of course) and turn it over backwards. Then retard the throttle and start over. Repeat as necessary until it fires.
Now someone is going to jump on me and say that turning it over backwards is not correct, or doesn't help, but,first, it is a safety precaution as the magneto couplers will not flip and any spark produced will be much weaker.(I neve trust switches or memory) Second, the air is being pumped from the exaust header, if I understand correctly, and will not add any additional gasoline vapors, which is not the case turning the prop forward.
That is what works best on my 85.
Darryl

[Dano"T"]

Re: Hot Start C-85?

I agree with that. My 85 is the same way. I turn her backwards with the switch off and throttle closed to help clear the cylinders. When it is cool (not below zero mind you) but just cool...it starts first blade very time with 1 prime AND 4 blades pull through. That's just mine though. They all have their quirks.

[Dano"T"]

Re: Hot Start C-85?

OOPS I meant pull backwards with throttle open.

[WLT]

Re: Hot Start C-85?

Deleted 6/18/05

[MAC]

Re: Hot Start C-85?

Thanks guys for the imputs. I'll do some experimenting in a day or two.