flame colour at idle

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The vast minority
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flame colour at idle

Post by The vast minority »

Sorted out the poor hot starting during the week, she was way too lean.

Lifting pin was siezed but after freeing off so that I could do the lift test, she died vary rapidly on lifting.

Now, after screwing the jet down I have her at the point the revs rise very slightly when lifted (as I recall is the correct situation) and both, hot and cold starts are instant.

looking inside the engine when running, I note the flame is very yellow though at idle and never really turns completley bunsen blue, even with a few thousand revs on the engine. I get a blue flame but its yellowish blue.

If I adjust the jet to get a blue flame from just above idle, then the hot starting deteriorates to the point she wont start. Th lift test also indicates this isnt right as she will die.

So, I suppose the question is this.
Do I leave alone now and accept she likes to be a bit rich or do I investigate why she needs to be a bit rich.....

Thoughts?


Al



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Panky
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Re: flame colour at idle

Post by Panky »

I've never found Colourtune plugs to be that accurate and just use one to get an idea of where to start.Try the plug colour check after a good run, if it's a bit sooty then lean it off a little.


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The vast minority
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Re: flame colour at idle

Post by The vast minority »

Panky wrote:
1 week ago
I've never found Colourtune plugs to be that accurate and just use one to get an idea of where to start.Try the plug colour check after a good run, if it's a bit sooty then lean it off a little.
I think your right buddy, Ill do just that.

Cheers
Al



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Re: flame colour at idle

Post by Sleeper »

IMHO. you need the mixture a little rich at tickover for smooth running.

John;-)



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Re: flame colour at idle

Post by The vast minority »

Sleeper wrote:
1 week ago
IMHO. you need the mixture a little rich at tickover for smooth running.

John;-)
I concur,
Running very well indeed now.

For your viewing pleasure.




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Re: flame colour at idle

Post by Custard »

Yes lifting pin test is correct.

The revs increase with the lift pin as you are lifting the needle so adding more fuel without opening the butterfly so no more air therefore a richer mixture. Then it falters as too rich.

I also think you can get different colours depending on which cylinder you check.

In the past I have had 1 and 4 plugs slightly different colour to 2 and 3 but left it if they were generally right.

While too rich isn't good, its safer to be slightly rich than too weak.

I also found that if they didn't need choke on a cool day that was an early sign they were a bit rich.

Tickover is smoother if to the rich side, but ignition timing also affects it (retarded is smooth but sluggish, advanced will pick up better but pink more easily) so I find the two go hand in hand a bit until you get it right. So you may find if you check and need to adjust the timing you then need to reset the tickover.

Sean.



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Re: flame colour at idle

Post by Panky »

The vast minority wrote:
1 week ago
Sleeper wrote:
1 week ago
IMHO. you need the mixture a little rich at tickover for smooth running.

John;-)
I concur,
Running very well indeed now.

For your viewing pleasure.

You can't get much smoother than that............nice :D


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Ted the 1971 Bermuda Blue Traveller
'91 Mini Cooper
1971 Commer Auto-Sleeper
!969 Commer Jennings Roadranger

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