This is not mini per se, but as most people run carbs I think it's still relevant.

I pulled apart the carb on my suzuki again on the weekend as i'm still having problems with it. I removed the jets to check them and they had a number stamped on them. Primary was 099 and secondary was 105. Obviously this is the size of the jets, but how are they measured exactly? I mean, what does the 105 mean?

Also, if I were to put on a set of extractors, port the head and fit a hotter cam, how would I choose the right jets? Is it a suck it & see thing? Best way would be to dyno it and adjust the jets so the AFR is not too lean not too rich, right?

_________________
Metal to burn, sparks to fly...

Not absolutely certain but most probably in hundredths of a millimetre. (Increments of 0.01 mm)
099 = 0.99 mm, 105 = 1.05mm.
You can check the 105 by carefully seeing if a 1.00mm drill bit will fit through the jet. Use the shank end for the test.

RonR

I think you might be on the money there Ron.

_________________
Metal to burn, sparks to fly...

Yep, that's how they calibrate them in Nikki carbs as fitted to many Japanese cars.

If you hot up the engine you will need bigger jets. There is no hard and fast rule how much bigger, unless someone has already tried exactly the same parts and can advise you what they are using.

You will probably find weber downdraft ones fit your carb - they did on a Gemini carb. They are easier to get than "genuine" ones too.

You can drill out the jets to a bigger size, but it makes it a hassle if you stuff it up.

_________________
Brett Nicholson
Greendale (near Ballan) VIC.
1971 Morris Mini Moke
1966 Austin Mini
1965 Morris Mini Traveller
1973 LR Series 3 88
2007 LR Freelander 2