Skip to main content
English French German Italian Spanish

Model 18 Timing

Forums

I took the oil pump out of my 1936 model 18 to put in the gasket which was missing. The good news is that this simple measure seems to have fixed it wet sumping. The bad news is I can't get it to start. 

I did my best not to disturb the timing when removing the magneto chain and sprockets and checked afterwards and the points are starting to open at 5/8 inch BTDC on the compression stroke with the points fully advanced which I think is correct.

My question is, if the machine won't start, and there is a good spark and fuel, is it likely to be a timing issue? Should I try advancing / retarding the timing a fraction or would I be barking up the wrong tree? 

Permalink

My 36 mag has weak magnetism and will not start with the mag retarded when the internal timing of the mag is not in its optimum position. I have to use some advance and be wary of kickback.Usually with these old warriors its not enough fuel getting through.

Permalink

Thanks for your comments. I've tried with the lever at every position from fully advanced to fully retarded but it stubbornly refuses to fire up. I'll take another look at the fuel supply and shift the timing a few degrees and have another go. Me being 11 stone in me boots doesn't help. 

Permalink

Don't damage your Achilles tendon by starting too far advanced. I saw it happen once. Check with great care. Also...check the plug. It might just be oiled up. With my bikes if nothing has been altered and they won't start, a clean plug usually sorts it immediately.

Permalink

.. a new plug rather than a cleaned one as current plugs are very difficult to clean properly.

Permalink

Thanks all for your comments. Richard, interesting comment about old style plugs.. what are their advantages and how would I find an equivalent for the 18mm NGK AB6 that I'm currently using? 

Permalink

Hi John,

   I don't want this to sound too obvious but the mag on the 1936 OHV engines runs in a clockwise direction when viewed from the timing side. Many of these magnetos had a tight wire advance because of this which can be confusing when setting the timing, so make sure the piston is in the right position and check the lever is correct for full advance.

Permalink

Thanks Richard.. yes it's a tight wire advance with the cable entering at the left side near the barrels looking from the points end of the mag.. I've spent the afternoon checking for continuity from the mag brush through to the plug, cleaned and re-gapped the points and dismantled and checked the advance/retard mechanism..tomorrow I'll recheck the timing and have another go at starting .. (with a new plug) sooner or later I'll get rid of the problem and be back on the road.. she can't hold out for ever : )

 


Norton Owners Club Website by White-Hot Design