Magneto timing 54 m16 engine

[Tazmantic]

Is the book value of 1/2 inch BTDC still ok for modern fuels?

Thanks

[SPRIDDLER]

Is the book value of 1/2 inch BTDC still ok for modern fuels?

Yep. You'll see references to 7/16" and 1/2" BTDC and either has been fine for my G3LS with no noticeable difference in performance. In fact I'd be well pleased if I could consistently get it timed exactly to either, i.e. within a 1/16th of an inch either way of the piston position in view of my fag paper technology, chain backlash, parallax error in lining up the stick marks at the plug 'ole, normal wear on parts. These old plonkers are very forgiving (and I'm no purist).

[Tazmantic]

Cheers Spriddler, well i had set it at 1/2" and it did seem to run ok ish but I ran her again tonight (after lots of things going wrong) and I found that I needed to retard the timing slightly on the lever to get it to run evenly, Ill try measure the timing tomorrow to see if something has slipped but if there was a fuelling issue would this cause me to have to adjust the timing..

Also and I think I've asked this before what jetting should I use fot 1 1/16" monobloc

25 or 30 pilot (I have both)

180 or 210 main (I have a 210 and 200)

I believe the book values are 30 and 210

Cheers

[SPRIDDLER]

I ran her again tonight (after lots of things going wrong) and I found that I needed to retard the timing slightly on the lever to get it to run evenly,

Was that in the shed or out on a run? It's my experience that when on the centre stand they'll always tick over more steadily, more slowly and reliably when the timing is retarded.

Ill try measure the timing tomorrow to see if something has slipped but if there was a fuelling issue would this cause me to have to adjust the timing..

In a word, no.

Also and I think I've asked this before what jetting should I use fot 1 1/16" monobloc
25 or 30 pilot (I have both)
180 or 210 main (I have a 210 and 200)
I believe the book values are 30 and 210

No experience of a 1 1/16" as mine has a 1" (I think) but if the book says 30 and 210 without an air filter fitted I'd start with that. You won't be able to assess the main jet without going out on a run as it doesn't really come into effect until half throttle or a bit more.

The Monobloc wasn't fitted to 350's until '55 onward but here are the settings from the AMAL document which you remember being recommended in a Forum reply in June......(When you've opened the document in the link below you can use the icons above the opened document to rotate and enlarge the text).


http://archives.jampot.dk/technical/Car ... 54_AMC.pdf

Carb settings 1954 350.JPG

[Tazmantic]

Thanks again Spriddler,

well I found that as I was checking the mag timing the timing gizmo kept flickering saying the points were open when they were not so I think the mag earth carbon was playing up gave it all a clean and fingers crossed seems ok now but I decided to remove the carb to measure the bore after reading another post and found the carb and head are 1 1/16 but the spacer block is 1 inch so looks like I need a different block or to bore it out