Have only just become a member in the last 2 weeks so go easy on me...have just purchased a 1961 ss dominator 500cc.....I am encountering a slight hiccup upon acceleration...tickover is fine....high revs are fine with the odd blip now and again....however the first quarter turn of the throttle is not responding if I twist the throttle quickly.....if I open up the throttle slowly it responds fine.....does anybody have any suggestions that can perhaps point me in the right direction....not sure if I should be looking for something timing related or maybe carburrettor related......any help greatly appreciated. Russ
Hi Russ. Welcome to the cl…
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Previously wrote: Hi Russ.…
Previously wrote:
Hi Russ. Welcome to the club. Sounds like weakness in the fuel mixture and that the throttle slide has too big a cutaway. I don't know what carb or carbs you have but the recommended slide for a 376 monoblock type is a "3 1/2" so you will require one with a smaller (richer) cutaway like a no 3 (smaller number is richer).
BUT before wasting time and money, you should check everything in the carbs especially float height and make sure everything is clean and unblocked. The existing slide/s could be wornand allowing air to pass around it thus weakening the mixture and therefore a new one wth theSAME cutaway number might be correct. As I said, 'tis best to go right through all the checks and inspections before buying anything.
Les
The Amal site has some guides available:
Thanks Lesfor the advice...I needed some pointers to give me a clue where to start with the fault finding process...think I will strip the carbs first and check for cleanliness...guess it will just be a process of elimination..will also read up on the website address you have sent me,,,,thankyou for now....Russ
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Previously wrote: Hi Russ.…
Previously wrote:
Hi Russ. Welcome to the club. Sounds like weakness in the fuel mixture and that the throttle slide has too big a cutaway. I don't know what carb or carbs you have but the recommended slide for a 376 monoblock type is a "3 1/2" so you will require one with a smaller (richer) cutaway like a no 3 (smaller number is richer).
BUT before wasting time and money, you should check everything in the carbs especially float height and make sure everything is clean and unblocked. The existing slide/s could be wornand allowing air to pass around it thus weakening the mixture and therefore a new one wth theSAME cutaway number might be correct. As I said, 'tis best to go right through all the checks and inspections before buying anything.
Les
The Amal site has some guides available:
Thanks Les.....spoke to the guys from Amal today and my word they were really really helpful...I have concentrics fitted at present, but am learning that I should possibly have monoblocs fitted for this year of bike...Russ
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Previously wrote: Have onl…
Previously wrote:
Have only just become a member in the last 2 weeks so go easy on me...have just purchased a 1961 ss dominator 500cc.....I am encountering a slight hiccup upon acceleration...tickover is fine....high revs are fine with the odd blip now and again....however the first quarter turn of the throttle is not responding if I twist the throttle quickly.....if I open up the throttle slowly it responds fine.....does anybody have any suggestions that can perhaps point me in the right direction....not sure if I should be looking for something timing related or maybe carburrettor related......any help greatly appreciated. Russ
hello Russ Right what Concentric carbs have you 926 or 626 , the jets are numbered differently too mono bloc carbs in a 500cc machine fitted with twin carbs the main jets are 170 main jets 25 pilot jet but you will not see a pilot jet there in a different place too the mono bloc, also air leaks between the carb and manifold can cause this problem , you can find them with gas lighter can or WD freeing oil just spay it on the joint between the carb and manifold a the engine ticking over if the revs rise then you know you have a air leak , allso fit Bosch W7DTC spark plugs you will find your bike starts Better and runs better too ? you get them for The Green Spark plug Co. on line www.greensparkplug.co.uk
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Hi Russ. Welcome to the club. Sounds like weakness in the fuel mixture and that the throttle slide has too big a cutaway. I don't know what carb or carbs you have but the recommended slide for a 376 monoblock type is a "3 1/2" so you will require one with a smaller (richer) cutaway like a no 3 (smaller number is richer).
BUT before wasting time and money, you should check everything in the carbs especially float height and make sure everything is clean and unblocked. The existing slide/s could be wornand allowing air to pass around it thus weakening the mixture and therefore a new one wth theSAME cutaway number might be correct. As I said, 'tis best to go right through all the checks and inspections before buying anything.
Les
The Amal site has some guides available:
http://www.amalcarb.co.uk/Downloads.aspx