Hi, I have a Mini Sprite 1983, Single HS4 carb and 12g295 head.
Since my rolling road tune the idle has been just above a thousand all the time which causes run on a fair amount.
The only way to settle it is to blip the throttle, it settles down to about 600 which is good but then within a couple of seconds rises back up.
The idle speed is on the lowest on the stop so can't be lowered any further, the throttle isn't open at all or sticking open.
The choke isn't sticking either.
Can't find what the problem may be? My only thought would be that the butterfly isn't sat properly and there is a gap for air to go through? but it didn't do it before the tune.
Any ideas?
High Idle When Warm.
Started by
thebullet
, Jul 02 2011 11:19 AM
7 replies to this topic
#2
stickycreambun
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Camshaft & Stage Two Head
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Posted 02 July 2011 - 11:37 AM
When I think I might have a possible issue like that I get some carb cleaner and spray a bit around the intake, if the butterfly was open it would drop the revs so you could start by looking at that?
#3
thebullet
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One Carb Or Two?
Posted 02 July 2011 - 12:18 PM
I will have a look, since I have changed the head which was fully restored and stripped the carb it has only done 3000 miles ish.
#4
cooperrodeo
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Speeding Along Now
Posted 02 July 2011 - 08:49 PM
If the idle speed is too high then you must have excessive air passing the throttle butterfly. This is likely to be either the buttrefly not closing properly owing to binding on the side of the carb or the stupid valve in the middle of the butterfly not closing sufficiently. You can check for the former by pushing the throttle towards its stop with a prodder. I assume a 1983 HS4 has that valve in the butterfly, in which case it is best removed.
#5
bmcecosse
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Crazy About Mini's
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Posted 02 July 2011 - 11:01 PM
Throttle cable too tight.......
#6
thebullet
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One Carb Or Two?
Posted 03 July 2011 - 10:26 AM
Will have a look at that valve, thanks
and I made sure the throttle cable wasn't too tight, it isn't pulling.
and I made sure the throttle cable wasn't too tight, it isn't pulling.
#7
Ivor Badger
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One Carb Or Two?
Posted 03 July 2011 - 11:16 AM
Have you tried adjusting the butterfly tickover screw?
#8
thebullet
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One Carb Or Two?
Posted 03 July 2011 - 12:44 PM
Have you tried adjusting the butterfly tickover screw?
Where abouts is this? havn't tried I don't think!
Or is this just the idle screw?
When I go to the throttle cable and the spindle part it is attached too isn't being lifted but it can be pushed a little bit down and it does slow it to about 700 rpm but this is more the spindle than the cable itself.
Edited by thebullet, 03 July 2011 - 01:13 PM.
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