Skip to main content
000000 000003 000006 000009 000012 000015 000018 000021 000024 000027 000030 000033 000036 000039 000042 000045 000048 000051 000054 000057 000060 000063 000066 000069 000072 000075 000078 000081 000084 000087 000090 000093 000096 000099 000102 000105 000108 000111 000114 000117 000120 000123 000126 000129 000132 000135 000138 000141 000144 000147 000150 000153 000156 000159 000162 000165 000168 000171 000174 000177 000180 000183 000186 000189 000192 000195 000198 000201 000204 000207 000210 000213 000216 000219 000222 000225 000228 000231 000234 000237 000240 000243 000246 000249 000252 000255 000258 000261 000264 000267 000270 000273 000276 000279 000282 000285 000288 000291 000294 000297 000300 000303 000306 000309 000312 000318 000321 000324 000327 000330 000333 000336 000339 000342 000345 000348 000351 000354 000357 000360 000363 000366 000369 000372 000375 000378 000381 000384 000387 000390 000393 000396 000399 000402 000405 000408 000411 000414 000417 000420 000423 000426 000429 000432 000435 000438 000441 000444 000447 000450 000453 000456 000459 000462 000465 000468 000471 000474 000477 000480 000483 000486 000489 000492 000495 000498 000501 000504 000507 000510 000513 000516 000519 000522 000525 000528 000531 000534 000537 000540 000543 000546 000549 000552 000555 000558 000561 000564 000567 000570 000573 000576 000579 000582 000585 000588 000591 000594 000597 000600 000603 000606 000609 000612 000615 000618 000621 000624 000627 000630 000633 000636 000639 000642 000645 000648 000651 000654 000657 000660 000663 000666 000669 000672 000675 000678 000681 000684 000687 000690 000693 000696 000699 000702 000705 000708 000711 000714 000717 000720 000723 000726 000729 000732 000735 000738 000741 000744 000747 000750 000753 000756 000759 000762 000765 000768 000771 000774 000777 000780 000783 000786 000789 000792 000795 000798 000801 000804 000807 000810 000813 000816 000819 000822 000825 000828 000831 000834 000837 000840 000843 000846 000849 000852 000855 000858 000861 000864 000867 000870 000873 000876 000879 000882
English French German Italian Spanish

Inter Timing

Forums

Edgar Franks quotes 52deg BTDC for the prewar Inters. But the post war value is 42.5 deg. There was, of course, only Pool petrol for rather a long time after the War. Does anyone know if that's why? I think I'll see 53 deg (I make that as much as 24mm piston drop), but mark 42.5 deg(16mm). So it gives me the chance to select more advance.

Any advice welcome. It's a p** to start at present. Mag cable is opposite entry direction to my 16H and I foolishly assumed it was tight wire advance....it's not!

Permalink

I see George Cohen said 37 degrees. So neither of the book figures...  anyway, hopefully it will be easier to start.

Permalink

Hi David,

   Looking at the first picture you sent in, it looks like you have the wrong mag fitted. The advance/retard cable should exit nearest the engine which means you do have a tight wire advance.

   The ES2 is 100mm stroke, the same as the model 30, but is 45 degrees or 5/8" (fully advanced) with lower compression than the Inter. 42 degrees is correct, but this can vary slightly depending on which fuel you use.

   Ignition timing is dependant on compression ratio and type of fuel, 37 degrees would be for around 9 to 1 comp. on premium petrol.

   With the engine cold try the ignition and the air lever halfway, and flood the carb. Keep the throttle closed but be ready to "catch it" when the engine fires, a valve lifter is a must, unless you bump-start it.

Permalink

Thanks Richard. I expected slack wire advance, and saw the wire entry on opposite side from my 16H....could have injured myself!

PO left notes on compression ratio.  I'll check and hopefully get it going this afternoon. I think it's about 9 to 1.

Permalink

If your Inter is 9:1 you probably have a Manx piston and no compression plates.  That's at the high end for a long stroke sohc Norton.   It would probably be better to drop the ratio a bit, if only for easier starting.  Once it's running OK you might consider raising it again if you wish.

The BTH racing mag, and Lucas MagDyno which I have are both tight wire for retard, and gives a weaker spark than on full advance.  The standard ignition timing is 42 1/2 degrees for a low compression Inter, 7:1.  There are probably people in the NOC who will remember what settings will work on higher compression. 

Paul

Permalink

Hi Paul (again.. I feel a bit ashamed of myself for all this cross posting, but it's been a steep learning curve...).

According to the extensive notes and if I have the final values, I think it is at 8.5. I set the timing (which is tight advance for some reason) to 37 deg BTDC on thin red lines on the lever, so I have a small amount left to pull.

Anyway.. much to my surprise I seem to have sorted starting it.

Routine I use is

Fuel on.

Turn over, using lever just at the peak of compression, with a couple of fingers over the air tube just to make sure there is gas all the way in

Retard on lever about 1/4" between my red lines

Bring up to comp, decompress over TDC

Tiny throttle and slide down.

Kick start. Often first kick, usually within 1st three. 

On Tuesday it started when warm when I was just turning over on part compression.

The thing to remember is to pull back to advance and open throttle very slowly. None of that 'blip the throttle' business...

I've read up about the air slide, but mine doesn't seem to have any noticeable effect. I don't know if that is usual.

 

 

Norton Owners Club Website by White-Hot Design

Privacy Policy