classic motorcycle forum

If 1/4in bsc is too slack try 9/32 bsf  .It is still 26tpi and just a 32nd bigger . I have used this size to repair a fair few 1/4 bsf  ,also 26tpi . the tricky bit is getting hold of good 9/32 taps and dies Geoff

At last ,a dry day and off we go. The gearbox is described as close ratio, wow they were not kidding. No real idea of speed as no speedo or rev counter. All was going really well untill the rather dodgy thread on the gear change connector rod pulled out !! back home in 1st gear. Some smoke but not worth chasing a sub for. Geoff  PS 84 years off the road for the bike  55 years for me on two wheels!!

That is the 500cc version of my 350cc, the huge long inlet pipe maybe one part of my problem ,being so long it will take a long time to reach a stable temperature ,with the fuel mixture condensing out on the walls of the pipe [its bloody cold here at the moment].. Yesterday I ran the bike for a good while started to get a better feel for the many control levers. After it had warmed up i tried again to get it to ldle against all that I know from vintage cars I left it at fullish advance 30/35deg  it seemed to work better like that . Still not stable at low revs hunting a lot and in the end it just died ,but a definite improvement. One other niggle is oil system ,its total loss  and after running for a while dribbles oily mess into its dirt tray  .I would like to check the output of the pump but cant run the engine with it disconnected ? Geoff

Thanks for the sound advice fellas, The engine is in reasonable nick, the piston/rings are fairly worn ,but from memory it is out at +40 .I toyed with the idea of a rebore or resleeve BUT ive heard horror stories of old cast iron pots cracking as a result . Looking around there are not a lot of 1929  355 barrels about . The reason for the one month delay on this update was a buggered calf muscle from when I forgot to retard the mag on starting ,boy that hurt!! Cardan I just picked up on your earlier post about the main jet  .038  is 1mm as near as the main jet  fitted is unmarked  but I think less than 38thou  Geoff

The fuel level in the carb is fixed [the valve stem has only one circlip position] I have checked the fuel level is at the top of the main jet ,which is as Amac paperwork .I have cleaned the carb several times and checked the pilot jet ways . Geoff

The reason I first asked about horizontal carbs was conflicting information about mounting the amac on my 29 Enfield . The old copy sales stuff shows a normal mount , but most of the images on the net show horizontal mount. I think now that if a bike was ordered with lights a longer inlet tract was used [to clear the magdyno] .My bike has the longer tract so room is not an issue. I am still having aggro trying to get it to start and run for more than a short while , the little sod seems to need to be flooded in order to keep running . I am starting to appreciate how easy electric starters are !! With a sore leg  Geoff

Many thanks for the replies, The oil system seems to be total loss with an adjustable output pump mounted on the magneto chain case. It sounds as if I may be on the right track anyway. I should just mention that its not just the bike thats been off the road for a long time , I sold my velo mac when I went to uni in 1966!! and yes I know the roads are busy and yes MUM I will be careful .Geoff