Trouble Finding 1st Gear After Start-up (Kick start)

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Dan1950

Dan1950

1974 MK II Roadster
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This problem arises mostly on a "cold" start-up. The gearbox shifted fine into all gears on the bench when the gearbox sprocket was turned. No problem finding 1st when roiling and less of a problem with a warm start-up.

Possible causes?

Primary chain too tight? ( there is >1/4" total chain deflection)

Insufficient end play in layshaft? (currently at .007")
 
Dan1950 said:
This problem arises mostly on a "cold" start-up. The gearbox shifted fine into all gears on the bench when the gearbox sprocket was turned. No problem finding 1st when roiling and less of a problem with a warm start-up.

Possible causes?

Primary chain too tight? ( there is >1/4" total chain deflection)

Insufficient end play in layshaft? (currently at .007")
Click to expand...
Let the clutch out for a second to get everything spinning then pull it in and try for first before it all stops dead.
 
Primary chain does sound a bit tight. Is that the deflection with the final drive chain pulled tight?
 
It can be the hairpin selector spring not set properly
Even upside down although I'm not sure what the symptoms are for that one
 
Derek Wilson said:
Primary chain does sound a bit tight. Is that the deflection with the final drive chain pulled tight?
Click to expand...
baz said:
It can be the hairpin selector spring not set properly
Even upside down although I'm not sure what the symptoms are for that one
Click to expand...
I'll try backing of on the primary chain tension and if that doesn't work, I'll remove the outer cover and have a closer look at the hairpin spring.
 
Dan1950 said:
I'll try backing of on the primary chain tension and if that doesn't work, I'll remove the outer cover and have a closer look at the hairpin spring.
Click to expand...
The hairpin is finicky and rarely works right out of the box, without some bending / adjustment. It needs to hold the pawl centered and fully seat both legs in the locator plate, all at the same time.
 
baz said:
It can be the hairpin selector spring not set properly
Click to expand...

An incorrectly set hairpin spring results in a missed selection because the pawl then doesn't engage with the ratchet.
 
Derek Wilson said:
The hairpin is finicky and rarely works right out of the box, without some bending / adjustment. It needs to hold the pawl centered and fully seat both legs in the locator plate, all at the same time.
Click to expand...
Just to be pedantic (apologies), but it mustn't 'hold' anything, no?
Correctly set it shouldn't touch the pawl at rest.....
(Assuming we're talking ratchet spring rather than return spring?)
 
Last edited:
I am refering to P/N 04.0038:

andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

It has to (gently) hold the ratchet pawl centralized in order to shift properly. Once the shift lever is moved, the spring will bias the pawl one way or the other, and engage the ratchet quadrant.

I have rarely (read never) found the spring to work perfectly out of the box without some fettling.

If you have a better way of setting this spring up - I am all ears.
 
From OldBritts Tech site:

There are three important things to check when putting this assembly together:

The ratchet spring (04-0038) is bent correctly so the legs DO NOT touch the gearshift paw (04-0024), but there should be just a very small but perceptible clearance on each side.

(Funnily enough, their accompanying photo shows a gap either side you could drive a bus through (Not what is needed!), yet AN show a photo with 'Gap' in large letters with a pic showing virtually nil, if any!!)
 
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EstuaryBoy said:
From OldBritts Tech site:

There are three important things to check when putting this assembly together:

The ratchet spring (04-0038) is bent correctly so the legs DO NOT touch the gearshift paw (04-0024), but there should be just a very small but perceptible clearance on each side.
Click to expand...
More pedanticism:

It is inevitable that the pawl will touch the spring - gravity takes care of this.

I agree - it cannot make hard contact with the pawl, but the clearance should be so minimal, it should almost touch.

I have set every transmission that I have been in (likely 20+) to this standard, and ended up with smooth shifting - so I can't be all wrong - lol

Otherwise - we can agree to disagree.
 
Holding the shift lever up as you just begin to engage the clutch is a work around.
Failing that, list here all the parts replaced.
 
concours said:
Holding the shift lever up as you just begin to engage the clutch is a work around.
Failing that, list here all the parts replaced.
Click to expand...
I had to do that ‘work around’ even after a pro gearbox rebuild by one of the good guys. I had therefore kinda assumed it was ‘normal Norton’?

Moot point for me now with a TTI tho.
 
Dan1950 said:
This problem arises mostly on a "cold" start-up. The gearbox shifted fine into all gears on the bench when the gearbox sprocket was turned.
Click to expand...

On the bench, the gearbox isn't being driven through the clutch. As the problem occurs when "cold" it is more likely to be clutch plate drag from oil on the plates.

Operating the clutch only 'lifts' the diaphragm spring, releasing the clamping force from the plates including the pressure plate but nothing physically separates the two sets of plates.
 
It's worth spending the time getting everything set up just right
My gearbox and clutch are quite possibly the best I've used
Certainly the best out of 6 old nails I own
No drag no slip, positive engagement etc it really is a pleasant gearchange
 
Fast Eddie said:
I had to do that ‘work around’ even after a pro gearbox rebuild by one of the good guys. I had therefore kinda assumed it was ‘normal Norton’?

Moot point for me now with a TTI tho.
Click to expand...
It's my normal procedure.
 

L.A.B. said:
On the bench, the gearbox isn't being driven through the clutch. As the problem occurs when "cold" it is more likely to be clutch plate drag from oil on the plates.

Operating the clutch only 'lifts' the diaphragm spring, releasing the clamping force from the plates including the pressure plate but nothing physically separates the two sets of plates.
Click to expand...
gortnipper said:
When cold, I always pull in the clutch lever and kick thru one or two strokes to release the clutch plates from one another before trying to start
Click to expand...
The clutch has brand new Barnett plates installed dry.and it is adjusted correctly. The steel plates were cleaned with brake cleaner and the primary is filled with 7oz of type F transmission fluid.

The clutch works superbly. No drag, easy to modulate and it engages firmly.

I loosened the primary chain but cannot road test the bike right now as I am working on other components. If that doesn't cure the problem I will remove the outer cover and check the spring on the shifter pawls.

I replaced the sleeve gear, the fourth gear layshaft gear, all bearings, bushings, all seals the kickstarter spring and the pawl spring.
 
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