To me running the Joe Hunt off the timing cover where the old points set up was is the most easiest way to go for mounting on a Commando, the idea of pulling the motor apart and doing major machine work to mount behind the cylinders then setting up a second chain to the timing chain and adding a AAU to retard the timing for easier starting is just too much and not needed, setting up to run straight off the end of the cam just like points and EI system is so easy, is a simple set up and to tune as well to do any maintenance when needed as it's just there.
What I have also done with my set up after setting it maggie in the right position at static timing (28 degrees) I have removed my JH and marked all my timing marks inside my old points area where the JH is set at so when and if I need to remove my JH off the Norton for any maintenance I set my timing on the 28 degrees then I can remove the JH from the bike and work on it on the bench for maintenance or replacing the point or anything really, once work is done I put the JH back on the marks I have scribed inside the old points cover area and all my timing is set, no need to retime the JH so simple the hardest part is setting the timing on 28 degrees lol.
But so far with running my JH on my Commando motor in over 12 years and over 30k miles on it I haven't done any maintenance on it, still running the point that came with it and only thing I have done in that time is to remove the front cover to inspect the points and a few drops of STP on the felt lube pad for the points cam arm.
I know Jim has said running the JH behind the cylinders he has never had any problems with heat from the cylinders, my Norton is well ridden and I do a lot of miles on it when out and about, Jim's Atlas is his test bike so not sure how many miles he clocks up when out and about, I do know a lot of Lucas maggies did have a few problems from heat running behind the cylinders as well sitting under the carbs if they leak, my JH runs so cool hanging out in the breeze, with both my old Triumph and Norton running off the side I never had any problems from heat.
But everyone seems to be obsess with retarding to start and as I have always said the JH fire up at full advance with ease as soon as I kick the Norton it will fire up but when carbs are all in tune with the JH, I still have a few minor fine adjustments to do to my old Amals but its running perfect its just the first cold start for the day is taking 2 or 3 kicks but once its started for the day it firing up on fist kick every time after that, but my Norton has a lot of compression and no chokes and its our winter.
Also so many are worried about the JH sticking out the side, this has never worried me in over 23 years of running a JH off both bikes in fact I love it out there, some say it looks ugly out there but to me it's not, and when people ask what is that it's great giving them some B S story about it, my best one is it's a anti theft device, get caught stealing my bike the plug leads be connected to your balls and I will give it a few kicks lol.
The JH is a solid bit of kit and I have gone down 2 x on the JH side and really the only damage to the JH was 2 seared off plug leads and a cracked front cover, a mate had a spare one so was a easy fix and I already had a tune up kit so had new plug leads, I just recently ordered 2 new tune up kits and 2 new spare covers for my spare parts cabinet, these should last a life time for me and the Norton and is there when needed but hopefully the Norton won't be going down again.
Also with the mounting bolts I use soft bolts so if I do gown down hard the bolts will sear and because the JHs are built strong the JH won't get damaged and slide away from the bike, so far the 2 times I been down was both slow speed accidents when one car turned in front of me and the second one was a quick first gear stop, did more damage to me than the bike and JH got my first broken bone out of that one, faulty old stock front brakes caused me to go down from that accident.
Well this is just my thoughts on running my JH off the side of my Norton as well my old Triumph, to me the ease of running it off the side directly off the end of the cam, no extra chain or AAU to worry about and no need to pull the timing cover off all the time to adjust timing chain or maggie chain as I run a auto cam chain adjuster and the best thing is ease of setting it up, doing any maintenance on it as well running in the cool fresh air is a big plus in my books and that big fat spark no matter what speed it spins.
Ashley
