The Marston Sunbeam Club & Register Forum

General Category => Technical Discussion Forum => Topic started by: 38lion on August 19, 2019, 07:40:15 PM

Title: Timing
Post by: 38lion on August 19, 2019, 07:40:15 PM
Trying to start my 1938 sv 600. I recently took of the oil pump side cover (internal pump) and have put it all back together and have timed it up as 1/2" before top dead centre, fully advanced, points just opening. It backfires!! and won't start. Have I done it wrong or are the settings different. It worked ok before work but it was such a long time ago that my father and I first did the timing. Any recommendations?
Title: Re: Timing
Post by: singleminded on August 19, 2019, 08:17:13 PM
Were both the valves closed,ie on compression stroke, when you timed it.
You've described exactly how to set up the timing.
Have you rechecked that the points still open at 1/2" btdc cos sometimes the mag shaft can slip when tightening the nut..I find that tightening the nut finger tight and then putting a larger socket over it so that the socket sits on the mag pinion and then tap the socket onto the pinion with a hammer ( not big thumps just a tap) will normally lock the pinion onto the taper and you get less slipping when the nut is fully tightened.  John
Title: Re: Timing
Post by: 38lion on August 20, 2019, 05:35:25 PM
Big thank you to John!!  Timing 180 degrees out and it's now a runner again.