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Re: stay-up flat problems on Premiers?
Curmudgeon #779640 07/24/19 11:53 pm
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I don't have the carbs with me but the two carbs were sold and labeled as a 32 mm matched Premier set for an 850 Norton Commando 1974 Mk11 - normal airbox and peashooter exhaust. (not a MK11A or Mk 111). Normal main jet for an 850 this configaration is 260.

Both had pilot 17 jet, 106 needle, 3.5 slides. One had 200 main. The other had 260 main. They both had the 850 Commando spray tube cutaway.

New plugs, gas and aircleaner

I changed both mains to 260
I changed pilot to 17 to 19 and then 21.
I changed the slides from 3.5 to 3.

All without the chokes.

The bike takes throttle when warm but not when cold.

I will now put the chokes back in and start again with 19 pilot and 3.5.

I don't have any issue with using the chokes rather the frustration of replacing all the tiny nipples on both the throttle cable and the choke cable. Honestly they are pure **** and I don't trust any manufacturer these days including Venhill because I have personaly witnessed so many pull off.

Last edited by johnm; 07/24/19 11:59 pm.
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Re: stay-up flat problems on Premiers?
Curmudgeon #779691 07/25/19 3:18 pm
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Quote
The choke slide is hidden inside the main slide until the throttle is opened,


With the proper cable installed, the air valve (choke) drops in front of the slide cutaway blocking air flow.

It has the same effect as if you installed a richer slide.

Re: stay-up flat problems on Premiers?
johnm #779731 07/26/19 5:33 am
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Originally Posted by johnm


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The bike takes throttle when warm but not when cold.

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How long does it take to warm up before it's rideable?

My 650 Tiger has no choke, starts first or second kick from cold (with tickling) but needs about 30 seconds idling before riding away, otherwise it stalls.

Re: stay-up flat problems on Premiers?
John Healy #779748 07/26/19 2:09 pm
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Originally Posted by John Healy
Quote
The choke slide is hidden inside the main slide until the throttle is opened,


With the proper cable installed, the air valve (choke) drops in front of the slide cutaway blocking air flow.

It has the same effect as if you installed a richer slide.


Yes, it comes into effect when the throttle is opened. When the throttle is closed as for starting it is ineffective, hence the need for a tickler


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Re: stay-up flat problems on Premiers?
Andy Higham #779756 07/26/19 4:31 pm
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it IS effective at idle BUT as it does not completely close off the air flow is the reason you still have to tickle the carb. as I have not tried it but my guess is you could kick it through several time with the ign. off than turn it on and have it start with out the tickler.

[quote=Andy Higham

Yes, it comes into effect when the throttle is opened. When the throttle is closed as for starting it is ineffective, hence the need for a tickler[/quote]


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Re: stay-up flat problems on Premiers?
Curmudgeon #779783 07/26/19 7:11 pm
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i didnt ride my bike for over a week. normally i use gravity to start it ( bump) only the choke no tickling. For science sake i tried to start it on the kicker , 3 kicks choke on ignition off to clear the clutch, ignition on, fired next kick, didnt catch, caught two kicks later. The choke does work, not very well, but it does work. it was a balmy 15 degrees C.
i hate tickling the carbs.

Last edited by gavin eisler; 07/26/19 7:13 pm.

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Re: stay-up flat problems on Premiers?
Curmudgeon #779792 07/26/19 9:07 pm
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The pilot circuit is metered by the pilot jet and the air screw (which gets its air from the outer hole on the back of the carb) however.... the slide is not completely closed when the throttle is shut, there’s a small gap underneath. You’ve probably got around 3/32 of open gap from the slide cutaway when the chose is down it closes this off.... the purpose doing so causes more vacuum to be drawn through the welsh plug and from the pilot circuit.

If your chokes aren’t touching the bottom of the bore then there’s a cabling issue.


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Re: stay-up flat problems on Premiers?
Curmudgeon #779923 07/28/19 7:04 pm
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What "Stay Up Flat" motorcycle tires are available?

OH! SORRY! It's a "stay-up- f l O a t" thread.

Re: stay-up flat problems on Premiers?
Dibnah #779934 07/28/19 9:54 pm
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Originally Posted by Dibnah
Originally Posted by johnm


-
-
The bike takes throttle when warm but not when cold.

-
-


How long does it take to warm up before it's rideable?

My 650 Tiger has no choke, starts first or second kick from cold (with tickling) but needs about 30 seconds idling before riding away, otherwise it stalls.


Perhaps three minutes. But i don't like to leave the bike idling that long because it is bad for camshafts in my opinion. I like to run the bike at about 2000 rpm as soon as it is started.

Last edited by johnm; 07/28/19 9:54 pm.
Re: stay-up flat problems on Premiers?
Irish Swede #779935 07/28/19 10:02 pm
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Originally Posted by Irish Swede
What "Stay Up Flat" motorcycle tires are available?

OH! SORRY! It's a "stay-up- f l O a t" thread.


facepalm


beerchug

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