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Discussion Starter #1
I have a 1974 T100R equipped with stock Amal 626 carburetors. The year and model specific parts catalogue calls for a size 150 main jet. The model specific and year specific Owners Handbook calls for a size 170 main jet. Both books are original Triumph publications. any thoughts as to what is the proper jet size for this year and model.
 

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Hi,

Firstly, welcome to the Forum. :)

Basically 150, 170 was for the single-carb. T100C.

However, note "Basically";150 was decided with pump fuel available in the late 1960's; fuel available today isn't the same, you'd be wise to start off with 150, follow the advice in http://amalcarb.co.uk/downloadfiles/amal/Mk1_Hints_and_Tips.pdf, http://amalcarb.co.uk/downloadfiles/amal/amal_tuning_guide.pdf and the various downloads available in Technical - The AMAL Carburetter Company, don't be surprised if the mixture turns to be weak and you need to increase the main jets size.

I'm moving this to the main CVV Forum, more people'll read it and the "Vintage Technical Tips & Tricks" sub-forum is really for posting 'em, not asking for 'em. :)

Hth.

Regards,
 

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Discussion Starter #3
I have a question about the following product: -
I have a 1974 T100R Triumph. All engine parts are stock. Exhaust is a modern day reproduction. I am in the process of buying new 626 26mm Amal Premier carburetors. I see these carburetors come standard from Amal with a #3 throttle slide and a 160 main jet. The Triumph published, year/model specific, parts catalogue calls for a #3.5 throttle slide and a 150 main jet. To complicate matters more the Triumph published year/model owners handbook also calls for a #3.5 throttle slide but calls for a 170 main jet. I realize with modern day petroleum the original specification no longer hold. Any guidance here as to main jet and throttle slide will be appreciate.
 

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Hi,

Before I merged them, post #3 above was the start of your third new thread in two days on the same topic. Please desist from starting a new thread every time you have another question on the same topic.

1974 T100R
626 26mm Amal Premier carburetors. I see these carburetors come standard from Amal with a #3 throttle slide and a 160 main jet. The Triumph published, year/model specific, parts catalogue
the Triumph published year/model owners handbook
Any guidance
If you read post #2 above, you'll see that I've explained already that the 170 main jet is a misprint.

Amal's modern change to a richer main jet and slide from those detailed in a 46-year-old parts book could have one of two reasons:-

. even the details in the '74 parts book could be misprinted (there are several others); #3/160 might've been what Amal actually supplied for '74;

. current Amal licencee Burlen Fuel Systems experience with modern fuel.

As I also posted in #2, you will need to experiment to find the parts and settings that give the best mixture for your bike's engine; as such, whether you start experimenting with 150 or 160 main jets, or #3 or #3-1/2 slides is neither here nor there. Nevertheless, you can ask Amal/Burlen to supply new carburettors fitted with whatever jets/slides/needles you desire.

Hth.

Regards,
 
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