1986 cb700sc Nighthawk timing marks or go with position of cam lobes . anything will help . no books to look at .

no 1 piston tdc
the cam lobes for no 1 piston should in such a position so that a slight turn of the cam shaft one way makes the exhaust start to close and the inlet start to open or the other way the inlet start to close and the exhaust start to open
this is known as valve rock or valve overlap and occurs when the cam shaft is properly timed to the tdc position of the piston
for a twin cam engine the cam lobes position will be the same operation just that the inlet cam rock will be for the inlet cam and the exhaust cam rock will be for the exhaust cam

[PDF]1986 Honda 200 Timing Marks

https://sandragb.com/1986-honda-200-timing-marks.pdf
honda 200 timing marks We have made it easy for you to find 1986 honda 200 timing marks without ... 1984 - 1985 CB14L-A2 Honda 700 CB700SC Nighthawk u0027Su00271984 - 1986 .... VT500FT Ascot, VT500C Shadow,VT500E Euro .

the cam shaft may be identifiable but I doubt it as the lobes will be all the same .It may take a trial fitting of the cam shaft to determine which is which. Place the no 1 piston on TDC and install the cam in the exhaust side of the head. position a the no 1 piston cam lobe in the just closing position. Check where the timing mark will be in this position ( the engine make and sized would have been an enormous help here as the key position or timing mark on the gear would have revealed what cam it was). Place the other cam in the position where the no1 cam lobe is just opening.. This is called valve overlap and from the positioning of the timing marks will show if the cams should be interchanged . The marks will either both face down, face each other or face upwards. If they face out wards away from each other then interchange the the cams and if that makes the marks face each other then it may be right. Another way ( probably simpler will be to put a cam in place and the cam lobes will be directly in line with the rockers over the valves or directly over the valves. Workshop manuals are a big help when doing this work.

check all fuse's and plugs check ignition modual and crank sensor check coil pack

The valve timing is off.

check the crank position sensor and cam position and wires are connected
reset the ECM using a scan tool that has the protocols for GM

if its a 6VE1 engine you might want to remove rocker covers and put front lobes of camshafts in position shown in picture with cam gear timmed up at same point cam gear are 3:1 ratio


look closely at cam gears in pic to see front lobe positions for both banks

from memory no4 on dissy when timing marks on cam timing in correct position, no 1 cam lobes should be "rocking" and no4 cylinder should be at top dead firing stroke(ignition)should be notch in dissy when cap is off or set so rotor button is lined up with cyl no 4 ht lead position