Can we get that type of volute spring? Drags list this one: https://draganfly.co.uk/shop/72243/volute-spring-for-cables/#6492A-37 This is the symmetrical - two small ends, fat in the middle, type we use for decompressor cables on singles. I've had one of those on my four, and was/am concerned that t...

The same arrangement is used on the cast iron 4G. For both of my 4Gs, I have used the volute spring and found it satisfactory. I understand the preference for the coil tension spring but wonder whether it isn't a greater hazard if or when the spring breaks. The coil tension spring on Madam's 1927 S...

This might help. You can see the bracket attached to the carburettor mounting stud - the volute spring normally goes between this and the butterfly lever.
As you can see, I don't use the volute spring!

tony.barnett wrote: ↑Tue Apr 30, 2024 1:16 pm So, I have concluded the investigate by returning to the scene of the crime - I readjusted the valve lifter - hesitation gone. Just need to put the carburation back to where it was. Thanks to all that tried to help.

So, for the future time when I fall into this hole (!), I guess it was too tight?

Thanks Ralf and Simon, I will order a new needle jet and needle and give this a try - would prefer to keep the carb original if possible! Alistair There's a few details here showing the wear in the needle: https://ariel-square-four.blogspot.com/2021/03/wng-finally-fixed.html?m=0 I think the most in...

My 1958 350 NH is fitted with a standard 376 monobloc with a 200 main jet, 106 needle jet, 25 pilot jet and 3 1/2 cutaway slide, C needle. It is running very rich at low throttle settings, sooting up the plug and misfiring if ridden in slow moving traffic.This is despite the throttle needle being s...

How does the throttle slide feel if you push and pull it through the bell mouth? Any fore & aft movement? Secondly, and not wishing to hijack your thread but my 1930 A also has a KC1. There's nothing mentioned in the despatch record; is it possible Ariel used BTH for a while during 1930 or are t...

Try here:

https://amalcarb.co.uk/carbspec/carbure ... es/id/4582

Looks like 106 needle jet, 15 needle jet.

Hi Barrie,

I've just seen the video you pm'd to me. Are they as noisy with the outer bearing fitted?

Perhaps post the video and see what others think?

Those OPRV's can be problematic at the best of times, in my experience, but the ball finding its way into the oil gallery must be the fault of the previous person who worked on the engine, surely? Has the inner end of the OPRV body been drilled-out at some time, I wonder? Allan. Maybe someone resea...