Hi folks ,
I have a 1961 BSA 10 running a new Amal 376/214 carb ( installed by the previous owner)
I have real problems starting from cold– initially I had a weak/ no spark on the left had cylinder- after changing the HT side components and cleaning the slip ring it looks to have sorted that as it will start first kick when warm BUT.
It is still a impossible to start from cold .
Unless bit of easy start us sprayed in the cylinders , then it wakes her up and she idles nicely ( hence me thinking the Mag spark is ok) – When inspecting plugs before the easy start they appear dry – not sure fuel is getting through or enough .
I have tickled the carb , tried with and without choke and with or without throttle , turned on both fuel taps but makes now real difference.
The other issue is although it idles well and revs freely – when it is in gear and accelerating it starts to hesitate and backing off on the throttle it starts to run fine again.
? I was just wanting to know the best order of investigation / changes . Should I just move the float needle up one position and try and then check the float hight . As I understanding the air mixture screw only influences the idle ( does not seem to be a problem).
Any advice gratefully received
Check the position of the needle in the throttle slide. The clip should be 3 down from the top. Also check slide number it should be 3 1/2 number on the top.
V helpful - appreciated.
My A10 likes to be tickled until fuel drips from the carb AND the air slide full down and about 1/4 throttle then it fires up straight away. Its a very cold blooded and just spits and pops without the choke on.
I assume the supplier jetted it correctly for your bike when you ordered it.
You mentioned that it starts fine when warm , so the carb can't be too far off.
If it pulls better at the top end if you back the twistgrip off , then that indicates the needle clip might benefit from being lowered 1 clip.
Also , you don't mentioned any tickling or use of choke from cold , this is likely to be your issue.
Use choke/tickle a bit until you find where it is happier from cold
Thanks for the comments - I have tried tickling once or multiple times and variations with the choke closed or at at different positions of open- it really makes no difference . I have also experimented with the throttle in different positions but have failed to find a combination that works. Based on the comments I will look at the needle position and if still and issue check the jet sizes and slider size . I don't think it is far away but just not getting those plugs wet and probably associated with the lack of response when I give it a bit of throttle when accelerating. Thanks again and will let you know how I get on.
Screw the idle air screw in a couple of turns too.
Thanks again folks , I have checked the needle position was the very top clip so as per Idie's suggestion I have moved the clip down two notches to position 3 of 5.
I aim to get it back together and try and start her and just check the idle screw and do a quick test run.
Also I gave the needle a bit of a polish as it had a couple of minor marks on the surface part way down the needle - but the needle looks newish with no bend in it.
They can be quite sensitive to these adjustments so fingers crossed it may sort it.
Hi,
Make sure that is no air leak at the carb/head joint.
Dave.
i might be sticking my neck out here.
but i had hard starting and poor pickup until i fitted a manual magneto.being able to find the a10 engines magic spots by fine tuning with the mag lever i now have reliable starting , hot or cold .
looking back , automatic units on mags seem crude for tunning.
if you have electronic ignition fitted , your on your own.