Thanks Rhys, I think my ratio is 7.2:1. I am making a a plate that will bolt to the engine and support two sprockets. Similar in design to tav but with reducing gears. It is what I have kicking around the garage. I am on a very low budget with this build and it has to be under a grand. So far  £400.

I have a selection of 4 sprockets which can give me final drive ratios ranging from 9.6:1 to 7.6:1.  At Stretton in November I was running 8.8:1 which was probably slightly undergeared as the governor was cutting in quite early on the straights but the hairpin slows you down so much that without a TAV the engine really labours as you accelerate out.  My first time out at Stretton the hairpin wasn't in our circuit and I was running 7.6:1 and it pulled it fine.

Well, I don't think my maths are up to much. I had 3 to 1 on the first chain from the engine and 4.1 to 1 on the second. I added them up and came up with 7.1 to 1. I actually had about 12 to 1. So I have made a couple of sets of change sprockets to alter the ratios. Currently 8 to 1. I also changed my steering slightly by adding another track rod. This made the wheel angles better at full lock. I felt I would get a lot of under steer using the kart type of set up.

Well, I don't think my maths are up to much. I had 3 to 1 on the first chain from the engine and 4.1 to 1 on the second. I added them up and came up with 7.1 to 1. I actually had about 12 to 1. So I have made a couple of sets of change sprockets to alter the ratios. Currently 8 to 1. I

Yes, you need to multiply them so 3 x 4.1 would have been 12.3 to 1. But I think if you now have 8 to 1 that's a very good ratio to start with.

Very impressed with your chassis fabrication!

AWESOME BUILD!!!!!
Is this fuel tank you are mocking up going to be functional or just a cover for the engine? Also, I love the back wheel and chassis and the radiator is looking cool. Cant wait to see this progress.

I love the tank idea and the use of CAD (cardboard aided design). this is going to be quite the cyclekart, I love the dodge baquet as a car

Dummy tank almost finished and an old bmx wheel held on with a quarter turn fixing with some brass finials.