Hi John, With Corona virus, I've had time to fool around with my bike & timing with degree wheel on cam shaft.
I spent a few days in shop making 1/4-28 adaptor stem to fit my Wassell degree wheel that is made to use on cam. (my factory made spindle is CEI thread).
So got that mounted on cam & that went well.
However I find using wire such as coat hanger is too wobbly & vibrates & hard to read with motor running. Motor off, static timing with points wire is fine, but not using strobe light.
This morning I made an aluminum plate that bolts to pillar bolts. Extends up to above degree wheel & has short wire pointer for degree wheel. Attaches to both pillar bolts & center of plate is cut out to access points/adjusters. This worked very well.
I could not find my old piston stop. As I recall it had 1/4" stem to stop piston. So I made one with 3/8 bolt like we used at Harley Davidson. As I recall I used 3/8 diam. stop on old 650s. But... maybe it was the 1/4" one. No matter this did not work.
Spark plug with insides cut out, threaded for 3/8" bolt turns out the intake valve hits the 3/8 bolt. Oddly you can turn motor past it as it hit lightly. I could feel motor drag, but not stop. Hope I didn't bend valve...
Normally, when piston hits stop, it's unmistakable. It just stops hard & instantly. No question. I don't recall having valve contact using piston stop before. However, I've never used the stop on T140 motor with 8.6 pistons, which have a low dome compared to 650... Plus I have .080" head gasket raising head .030" over standard. Motor started & idled after so I think I'm ok. I didn't force anything. Valves are pretty stiff, but yikes! What about bending push rod?? I don't think I did. Motor didn't tick after starting like a loose valve clearance, which is sure sign of bent valve or push rod.
I may or may not make another piston stop tomorrow. I doubt it, but we'll see. I will make one though.
So I used my TDC tool to locate crank & set degree wheel from there. This worked very good & easy as expected.
A quick note the degree wheel is plastic. It holds to mounting spindle fairly well. Very well for static timing. However you need to be sure it's very secure or it wants to slip on spindle. A quick check is to make witness mark on wheel, spindle and/or recheck zero with TDC tool.
Of course I put fan in front of motor to cool it & keep plastic degree wheel cool as it's close to header pipe.
Finally, I started motor let warm briefly. Timing light showed perfectly, just the same as it does on alternator rotor. Timing advanced as expected & was 36B at 2000+ rpm. I use 36B instead of 38B to reduce ping. (Boyer
has different advance curve which is much better).
So if... you can locate TDC or 38B & set cam mounted degree wheel to it depending on your flywheel notches, it indeed works well to use cam mounted degree wheel to strobe time motor.
PM me your Email & I can send photos of what I have if you are interested.
Truth be told, a used primary cover off eBay
with timing pointer is good way to go. You could use a later T140 one also with the screw in plug. Just put a stopper of some sort in gear shift hole. Even silver tape would probably work. Dents or cracks no problem for just setting timing. Epoxy cracks as/if needed.
Following timing on Boyers now, I find indeed once set, the timing stays spot on for many thousands of miles so long as parts in timing cover are not disturbed. So fitting of junker cover to set timing is only needed once for the most part. Certainly worth the cost of a junker cover.
Quick question. Can you remove your primary cover with exhaust pipe & muffler on? I found on the '69 Bonnie if you use Allan head bolts along bottom & remove with a cut down Allen wrench cover will slide out & up enough to not remove exhaust, which is a pain with crossover pipe etc. I don't know on earlier.
Our county says no pleasure riding of motorcycles, but you can play golf or go out walking. This shelter in home is getting old fast. Order lasts until April 7.
So catching up on a few projects.