Mark have you got the Thorspark up and running? I am thinking of going this route as well. I am light in body weight and have a hard time turning the motor over fast enough at start up, even with full retard I normally have to run with the bike and bump start. If I get stuck on our local ferry system I may have to wait until high tide to roll off the boat.
My 52 B33 is currently running mag/dyno with 6 volt positive ground. I realize Thorspark sells these units to match both voltages but I am kind of thinking running the unit as a seperate unit powered off of my 12v rechargable lithium battery from my cordless drill. It is a 2ah pack so should keep thet bike running for 8 hours no problem according to manufacturers amp draw specs. I also have two of these pack and they are very tiny. I was thinking of tucking the coil and one of the lithium packs in my little saddle bags shown below. This way I can run a 12volt horn or what ever off of the pack as well. Any thoughts or feedback much appreciated, I have not heard much about this system until I stumbled onto it through this post. Sounds like a good deal for around 200 bucks and leaves the bike looking some what stock with the ability to still use  my manual advance lever at the handle bars.....thanks wayne

Thanks a bunch Calum and Pete, the information PDF and the comments will help a lot. Waiting for a few parts still to come before putting it all back together and tackling the end float adjustments - I will update as things go.
One further question please.........I am thinking the clutch on my B33 is a dry clutch but not sure on how it works best. I realize oil from the primary splashes around in the clutch area and must somewhat put some oil on the clutch plates but does the clutch really need any oil on it for proper working? The reason I ask is, the few miles i put on this bike I would prefer to just spray some chain lube on the primary chain through the inspection port and forget about keeping a level of oil in the primary case as its prome to leaking and seems like a loosing battle. If I just spray chain  lube on the chain as needed will my clutch suffer in giving smooth workings. I am now installing new clutch plates with the gear box fixup so looking forward to fewer leaks and a smoother running machine . .........thanks wayne

Thanks Jim, the old clutch center has one of its studs with what looks like a saw cut half way through its diameter. No idea how this would have happened but the studs strength has for sure been compromised. I have a little tig welder and if I had a new stud I could easily tack a replacement stud in place but I have not found a part number for the stud or found a source for a single new stud so I just ordered the whole clutch center based on numbers from the BSA parts book.And yes the parts book I have is confusing for sure, for instance some of the bushings I would like to replace in the gear box - the parts book implies for the B33 you have to buy the gear and its bush as a whole unit which is pricey and yet the parts book implies other models like the clubman you can buy just the bush so kind of confused but learning as I go. Thanks for the input Jim, appreciate it. ........wayne

HI Rog1 and 750 rideruk. PHoto shows where I am at presently. Pulled off the clutch center by pulling on the Clutch chain wheel with a reg outside puller. So part of the center clutch is off complete with its outer bearing race which appears to be pressed into the clutch chain ring. The inermost part of the clutch center containing its inside bearing race and bearings still need to be pulled off of the mainshaft. Photo shows with lines drawn in red to denote the measurement I have taken on the outside diameter of the threads that I guess the proper BSA clutch puller tool would fit to. The OD is 1.181" or 30mm. HOpe this helps, I have a puller on order so I will wait to see if it fits......wayne

I was watching a video online that shows clutch removal for a complete tear down. It showed first a puller used on the clutch center then a second pull of the clutch chain ring after that. It seems like the puller needed for the clutch center if pulled first would need to have very thin tabs for pulling which I dont have. My question please is... can I pull the clutch chain ring and the clutch center both off at the same time by putting my puller straight onto the chain ring? My puller will fit for this but not sure if this will work because in  Brain Alfonso's restoratin video he did it with two pulls so thinking their must be a reason he did it this way? ....thanks wayne

Thanks Pete, good point on prying from the front part of the cover. Photo shows what worked real well for me. Yes it looks like silicone on both sides of the gasket, someone must have been tired of this primary cover leaking I guess .
Now that the cover is off I want to look at my clutch as it has been slipping. I have a couple of questions please as my manual is not really helping with some things I am not sure about........
1. I want to get the Clutch Center off but not real sure if the Mainshaft nut is a left or right hand thread? Pretty sure its a left hand but want to double check before putting an impact gun on it.
2. Second question is the "Clutch Center" has one of its 6 threaded rods come loose from its tack weld shown on the inside of the center in the photo. Not sure if these spot welds are from the factory or a handy man solution. I have a welder but I dont want to add too much heat to this area to re spot weld incase I warp things. Maybe the spot welds are just to kind of hold the bolts in for installing springs etc and dont really need strength at the welds but until I get the Clutch Center off I have no idea how the bolts or threaded rods are held in place. This threaded rod will wiggle but not spin so maybe its OK as is?
3. Just curious on this one, I have seen people use brake clean on the clutch plates an friction plates but if all the primary oil is flying around in the primary during operation Im curious as to why it would matter if the clutch plates are oily before installing.
.........thanks in advance for any help on this.......wayne

As Jim has mentioned about the tank being a possible source I also have found this to be true. My B33 sounded like a clothes dryer running a full load of loose ball bearings BUT only when the bike was in motion and only in the higher revs. Turned out it was the Gas tank. The sleeve in the frame that contains the nut & bolt at the Gas TAnk ears was the culprit. I made a new tigher fitting sleeve and also improved the all the rubber mounting points so no way the tank can rattle. Just a thought but perhaps double check that there are no metal parts of the tank touching or close to touching the frame.
I mention this as you have stated the noise is at certain speeds, I am guessing if the noise is not heard when reving in neutral you may have a similar problem to mine and Jim's.....wayne

Thanks a bunch Pete, my email is waynebergman@gmail.com ...wayne