BSA B31 Timing and Pushrods

Replacing both pushrods after heavy kick back, reset ignition timing

[@UPTHETOWN]

Good to see you back Mr A

[@hunterjamison4808]

Really nice rebuild! When I rotate mine for the .003 clearance they change , probably bent. I wasn’t aware that new push rods are available, that’s good news! They might possibly be straightend with 2 v-blocks and a light verticle press using a couple of indicators. I reheat my copper washers on the rockerbox shafts for best possible oilseal.

[@500dbd34]

Hunter, so does mine, I aim for 003" at the tightest point, I don't think a thou either way is a problem. Mate of mine has a Royal Enfield which has zero clarance cold, still works great. Cheers B

[@retromechanicalengineer]

Great video Brian as usual. She runs sweet now! Best wishes, Dean in Oxfordshire.

[@500dbd34]

cheers

[@hunterjamison4808]

It sure would be great watching you go thru one of those older gearboxes!👍

[@500dbd34]

I might have a go at this, hoping to start another B31 restoration soon. Cheers B

[@davidclapham1066]

Nice video Brian. I was surprised at the difference in timing from a C12 to the B31 - 3/64 to 7/16 BTDC. Do you know why so different and why a C12 doesn't tend to kick back while so much further advanced?

[@davidclapham1066]

Oh, the penny just dropped - more advanced, less likely to kick you over the moon :-)

[@500dbd34]

@@davidclapham1066 Dave, the advance and retard is automatic on the c12, I timed mine at 12 degrees BTDC, see my C12 restoration part 11 to see how I did it.

[@TheLAGONAS]

hello sir,where did you get this device magneto static timing light?

[@500dbd34]

Hi, there available on EBay £38 ish. From the Magneto Guys. Cheers B

[@bobridgwell3152]

Hi can you explain how the push rod got bent please , i can,t understand how unless a rocker or valve siezed !! Bob R

[@500dbd34]

Hi Bob, yes one of the valves seized and the pushrod popped off the tappet. All ok now. Thanks for the comment. New valve guides need to be reamed out 1 1/2 thou which can be bit tricky to measure, I left mine a bit tight. Cheers Brian

[@500dbd34]

Bob just to confirm that I don’t think the kickback caused the problem but it did pop the pushrod off the tappet

[@danielgoutiere2493]

👉👏👏👏