Point Gap - same technique as usual?

[cappisj1]

So, when you adjust point gaps do you still use the slight drag feel? It’s more like a visual of watching the point arm move more open when the feeler goes in. Or, do you set the points so the feeler goes in without moving the arm any?

I use the middle of the range feeler and try to get the arm to move a smidge or a tiny bit of drag sill.

Just wondering how others do it.

[SportsterDoc]

With some drag on the feeler gauge, the gap will be slightly less than specified, resulting in slightly longer dwell time.
As the cam follower wears (hopefully with cam grease, many miles later) the dwell is reduced.

So, slight drag on the feeler gauge is OK/preferred .   Out of spec dwell/point gap does affect timing.

Checking with a dwell meter would be good.   Wish I could remember what I did with my Hawk engine analyzer

[Moparnut72]

Plug gap is more critical than I thought at least with 70 year old magnetos. I have little used old Johnson outboard that I got from a collector friend. I use it a couple of times a year as the motor on a tow boat at our races. Since I have had it it will not cold first thing in the morning on choke but has to be primed. Yesterday I pulled it out, no start. I pulled the plugs, hadn't paid much attention to them in the past as they are damn near new. It turns out the gap was fairly wide, spec is .025. I re-gapped them and thing fired first pull. I guess it pays to double check everything.   
kk

[n3303j]

Point gap (and dwell) isn't super critical on our low RPM two cylinder engines. Plenty of time to saturate the magnetic field in between required sparks.

Spark timing is far more critical for both performance and durability of the engine. You can easily get proper timing from 0.014" to 0.018" points gap by proper rotation of the distributor. (The lower gap produces less rubbing block wear and chances of "bounce").

So come reasonably close to 0.016" on your gap with the feeler just touching the contacts on new points (without any humps from use) and you will be fine. Just be sure to check and set your timing after setting the point gap. As an aside; If you fuss over gap and have to change points on a road trip (who kniws why?) chances are you will be close in timing if you fuss equally when installing the replacements.

As an aside I get twice the joy of points adjustment with the dual set in the T3. File and scrape as I could I could not get both cylinders timed equally. I set an 0.002" difference in point gap between S and D and the timing is correct for both cylinders. I split the difference around 0.016". Rins fine fir 113,000 miles so far.

[Cdn850T5NT]

Ron, that's interesting to know... My T5 series III has twin points too. So the moral of the story is NOT to blow your brains out re equal gap, but rather to concentrate on comparative Timing, that the chosen gap gives. However, you CAN advance one set of points versus the other, a bit in any case. Will file it away for future reference. Thx 🙂.

[cappisj1]

Ron, I did this mod on my T. I too had to give and take to get the timing as close as I could. By doing this it’s timed perfect.

https://www.thisoldtractor.com/moto_guzzi_tonti_distributor_dual_points_plate_modification_so_you_can_time_both_cylinders_properly.html 

[n3303j]

Ron, I did this mod on my T. I too had to give and take to get the timing as close as I could. By doing this it’s timed perfect.

https://www.thisoldtractor.com/moto_guzzi_tonti_distributor_dual_points_plate_modification_so_you_can_time_both_cylinders_properly.html

I did file the adjustable plate but did not want to hack up the base plate so I finished the job with gap differential.

[Moparnut72]

I play with old Mercury outboards. The 50's twin cylinders had dual points, one for each cylinder. The procedure is to set point gaps the same on each cylinder. Then time #1 cylinder. The second cylinder is then timed by altering the point gap to get the timing correct on that cylinder. This procedure is nothing new.
kk

[n3303j]

I play with old Mercury outboards. The 50's twin cylinders had dual points, one for each cylinder. The procedure is to set point gaps the same on each cylinder. Then time #1 cylinder. The second cylinder is then timed by altering the point gap to get the timing correct on that cylinder. This procedure is nothing new.
kk

I'm older than your outboards.

[Moparnut72]

So am I. I ran a fairly new '52 Mercury Super 10 Hurricane in the '50's. I also have a couple of mid '40's Mercs that were born the same time as me. I used to say I'm getting old, now it's s**t I'm old. I think my old outboards run better than I can. 
kk

[Cdn850T5NT]

Seems to me that opening up the gap gives more advance? If you did not want to clearance the point plate, could you set the points at 0.0155" (however unlikely that you can achieve this precise gap) - but set it midway between 0.014 and 0.017) and then when cyl 1 is timed correctly, rely on opening or closing the gap on points for cyl 2 - and be able (staying between 14 and 17)  to properly time cyl 2?

[n3303j]

Seems to me that opening up the gap gives more advance? If you did not want to clearance the point plate, could you set the points at 0.0155" (however unlikely that you can achieve this precise gap) - but set it midway between 0.014 and 0.017) and then when cyl 1 is timed correctly, rely on opening or closing the gap on points for cyl 2 - and be able (staying between 14 and 17)  to properly time cyl 2?

Yup, kind of what I said. Set #1 at nominal gap and time with distributor rotation. Use up the adjustment plate movement on points #2 then tweak gap until cylinder #2 is correctly timed.

If you measure and record both gaps you can use those figures if you replace the points. You'll find that distributor rotation is really close to correct at installation.

[Cdn850T5NT]

Ron -👍. I forgot about trying the points plate FIRST, limited travel as it is...