376 Amal Carburetter Monobloc

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376 Amal Carburetter Monobloc

Postby nymanjoseph » Wed Nov 18, 2020 2:17 pm

I bought a AJS Model 14 a few months back,i am happy with the bike but i am having trouble getting the tick over correct.The bike starts easily and so i guess things are almost right.To start with i thought i would adjust the throttle stop screw,it is almost impossible to turn the screw to tighten against the spring and so i bought a new screw and it is the same.Any ideas ? Thank you Denis.

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Re: 376 Amal Carburetter Monobloc

Postby Mick D » Wed Nov 18, 2020 2:58 pm

Hi

Remove the spring and see if the screw is still tight, if so it's one of two possible causes:

1. The plain portion of the screw is binding in it's bore due, probably, to gum or corrosion - carefully clean out the bore with a twist drill the same size as the plain portion of the screw, (do this by hand, with a pin vice if you have one, don't be tempted to put the drill bit into a drill.

2. The thread is binding, again gum or corrosion are the prime suspects - the thread is 2BA, get a plug tap and clean it out.

Both remedies will be easier with the carb removed and it should be scrupulously cleaned afterwards.

Regards Mick

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Re: 376 Amal Carburetter Monobloc

Postby nymanjoseph » Wed Nov 18, 2020 3:16 pm

Thank you Mick i will give all of that a try.
Denis.

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Re: 376 Amal Carburetter Monobloc

Postby nymanjoseph » Sat Nov 21, 2020 3:00 pm

I have taken the carb off carefully cleaned the thread out with a 2BA tap and made sure there is no gum on the plain section hole .The adjuster now screws in with no trouble but when it is fully home does not increase the revs,i guess it is not touching the throttle slide but why i have no idea.

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Re: 376 Amal Carburetter Monobloc

Postby Rob Harknett » Sat Nov 21, 2020 3:32 pm

http://archives.jampot.dk/technical/Car ... 60_AMC.pdf
http://archives.jampot.dk/technical/Car ... d_tips.pdf
http://archives.jampot.dk/technical/Car ... t_1957.pdf
Study the above info, check you have the correct carb, jets etc. You did not state the year of your bike.
Members need to know exactly what year / model bike you have. Quite often they are told e.g. mod 14 when they in fact have a mod 14 CSR.
Have you the correct spring ? or something longer ? you may be able to count the number of turns for the spring in the parts list above as drawings are very good.

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Re: 376 Amal Carburetter Monobloc

Postby Mick D » Sat Nov 21, 2020 4:06 pm

Hi

Take the throttle slide out and have a look for damage where the stop screw contacts it, if all looks good go back to basics and check you have the correct jets and needle position. Set the air screw 1.5 turns out and back the throttle stop right off. Will it start?

If it starts you can use the guide Rob linked to set the tick over.

Regards Mick

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Re: 376 Amal Carburetter Monobloc

Postby nymanjoseph » Sat Nov 21, 2020 6:47 pm

Take your points Rob.Getting back to classic bikes after some 20 years and so a bit rusty.It is a Model 14 CSR 1965.I was told after i bought the bike that the owner had trouble with the tick over,not to worry.
Info that was provided was that the carb and tank were completely cleaned out and that needle position was moved from Four to Three but could not give me any reason for this.
I will follow all advice and thank you all for your help.
Regards Denis.

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Re: 376 Amal Carburetter Monobloc

Postby 1608 » Sat Nov 21, 2020 7:43 pm

Rob may have a point. Perhaps the spring is too long/wrong one, and binding up. Try the screw without the spring.

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Re: 376 Amal Carburetter Monobloc

Postby Rob Harknett » Sat Nov 21, 2020 7:48 pm

I did say study the above and check you have the correct carb. Not much good answering question's if you don't have the correct carb for 65 14 CSR
So check you have a 389/82 not a 376.
http://archives.jampot.dk/technical/Car ... e_Scan.pdf
The above will show you jets etc for 389/82. I believe this carb has a large bore normally used on a 500.
I made an excel file to make a quick check cabs fitted to AJS 1933 to 1965 you will see it listed here.
http://archives.jampot.dk/technical/Carburation/

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