Hi Paul. I was the same, no idea how to go about building one. Part of the build process for me was to learn new skills, welding, fibre-glassing, woodwork etc. I'm glad I took the plunge and now have two cyclekarts, and a load of new skills (although my welding could do with considerable improvement)  I'm only over at Matlock so not far from Notts. If you fancy a ride over in the new year for a chat over a brew and a look round my cyclekarts I'm happy to answer any questions you may have. Would be good to have someone else in the Notts Derby area that's part of the club.     

I used 25mm bearing pillow blocks on my Peerless 100 ( had the shafts machined down to 25mm and keyways cut fill length first) bolted through the chassis so its just a case of unbolting and lifting off if need be. I never liked the idea of cutting away most of the chassis rail then relying on the bearing housing for strength so went this way about it.

I used this hope it helps https://www.bmikarts.com/go-kart-gear-ratio-calculator-jackshaft-setup

I had a 120 main, but it ran a bit rich, found 115 better for my Hyundai engine.
Ran a 125 main with the Lifan engine which was Ok. Think its a bit of trial and error to find what works best. I found the VM22 clone a bit of a pain in the arse with fuel leaks and lost track time messing about with it, others have run them no problem. I just did not get on with them so no longer use them.
Or it could be I was just rubbish at setting them up.

Transverse front spring set up and broken panhard rod bolt

Following my little tumble I had a look at what caused the issue, I had installed a home made Panhard rod similar in size to track rods used on go carts. This was made to stop “side to side” movement of the front axle. This worked and I achieved no “side to side” movement (there will always be a bit of movement because of the panhard arc) on the front axle.
This was placed behind the front axle and a 1 inch spacer used where the red arrow shows to bring the panhard parallel to the axle.

The home made panhard rod was fine and worked well for two years but the M8 bolt that fastened to the chassis was just not up to the job, I think this was compounded by the use of the 1 inch spacer putting extra sideways pressure on the bolt. So while driving on the inside edge of the track on a rough bit of concrete it gave up and snapped causing me to have no control on steering and have a rather large tumble.

So a complete redesign was needed.  While recovering from a broken Coracoid and other shoulder damage I had plenty of time to google research panhard rod set ups, I needed something stronger that would not fail as my homemade set up had done. So In the end I went for Kia Sportage rod as it was almost the same length and was a good price.

I had the same set up on my other cyclekart and as that was in the garage decided to upgrade that one first .I also changer the position of the panhard rod to now be above the front axle rather than behind it.

The rod is rather bulky and probably a bit over done but with M14 bolts its should now do the job.

You would have to ask the CKGB committee the question as it would be they who decide. Link below
https://www.cyclekartsgb.com/ckgb

Both Tim And myself went for the:
https://www.amazon.co.uk/dp/B0BCVN9G6Q
I let Tim do all the testing and setting up, then I just took his advice and bunged the 100 jet in and lifted the needle one grove. well happy with it.   
Much better quality than the VM22 Mikuni copy that i could never realy get set up right.   

100% off work that day