Tickle or Choke

Started by Barnsey, 30 Aug, 2026, 09:40

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Barnsey

Well, I managed to get it to start eventually this morning.  I'll have another go on Friday, when I am at home.  But I think it might need the idle and maybe the mixture, tweeking a bit.  It stalled after warming up, when I backed off the throttle. 

rhyatt

Well done ,
When you next try , get it going and hold the twist grip carefully keeping it going.
Then bring the tickover screw up a bit to allow you to release the twistgrip.
Then , carefully, tweak the air screw in and out to get a steady tickover . This screw is nominally all the way in and 1.5 turns out (but around that is fine , don't get fixated on this)

V500

You should add that the engine needs to be up to working temp before tweaking the mixture etc.

rhyatt

Yep , forgot that , most important bit

iansoady

Quote from: limeyrob on 31 Aug, 2026, 16:01 I also think a lot depends on the idle screw setting. If the idle circuit mixture has been set before the engine is fully warmed up it will be too rich which will allow it to start and run without the slide.  If its set correctly on the idle mix its likely to need 1/2 slide for a minute or two to stop it spitting back.

I can't see that 1/2 slide does anything at idle speeds as the choke slide will be up inside the throttle slide and won't come into operation until half throttle or so. It's a pretty crude device anyway.

Amal used to provide a device on the throttle stop for 276 type carbs to raise the slide slightly for cold starts, but I think was only available on Nortons and Velos. I adapted the idea for the Wassell Evolution on my Electra to allow for it to idle both when cold and warm.

Ian.
1964 Norton Electra
1969 BSA / Suzuki DZR400 / Steib S501
2016 Herald Classic 250

limeyrob

You may well be correct. But I've noticed that my RR picks up better and runs cleaner with some slide.  Its very cold blooded and takes a while to settle to smooth running. If I blip the throttle it will die without some slide, perhaps the blipping is bringing the slide into the flow.

Barnsey

After the joys of getting the bike started last weekend, it is back to not wanting to know today.  I set the mixture screw to 1 1/2 turns and the idle to just lift the slide. 

  I've tried tweeking all the variables I can think of, including kicking over with switches off to clear flooding. 

  Lots of kicking.  Just the occasional splutter and then back to nothing.

Barnsey

It looks like it is all down to technique.  Ray came over this afternoon, and stomped on the starter with his (must be) 14 stones.  The bike started right up.  I am going to strap on my exercise weight belt.  My 10st 8 lbs just isn't cutting it. 

Andy Kay

I have to agree that there is no definitive method of starting the damned things.
My B44 to my mind was a pig to start. So I have fitted the choke slide that came with the new carburettor.
She's still an awkward bugger!
The one thing I have discovered is to either use the choke or tickle the carb, but don't do both.
It still takes 4 or 5 attempts before she fires up whichever method I use and if she cuts out it takes about 3 attempts to get her going again even though she's well up to temperature.
I've tried a myriad of techniques, but all to no avail.
One thing I have found useful is my old Gunsons Colourtune to get the mixture right at tick over.
Of course all the rest is down to having the correct size jets fitted which can be a nightmare to ascertain as BSA, in the case of the B44 seemed to alter the sizes every year. Even though the engine and carburettor type were identical.

Barnsey

If I can get to the point that I can start my bike in three kicks I will be pretty chuffed.