GS 160 Points Timing -Help please !!!
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Member
GS 160 Mk.2
Joined: 21 Oct 2013
Posts: 22
Location: East Sussex, UK
Wed Jan 08, 2014 11:26 am quote
Have attempted to set timing but end up with the 3 stator tightening screws being right at the end of their slots to try to reduce the degrees of advance to 26. Previous visible marks suggest the setting has been around the middle of the slots. I have used a piston-stopper and a multimeter (alternatively on buzzer/continuity and resistance settings) together with a degree wheel. My ignition coil (HV) is disconnected, as is the battery.
I am reasonably confident in the points gap. Could there be an issue with the points cam (which so far, I have not examined)? How does it locate correctly on the crankshaft? I believe there is a spring ring but, after it passes over the woodruff key does that ensure it will be reliably in place?
Any other tips/ideas, please? I believe this scoot to be stock.
Molto Verboso
Joined: 31 May 2009
Posts: 1221
Location: NC, USA
Wed Jan 08, 2014 1:53 pm quote
The points cam should have the words lato esterno facing outwards for the cam profile to work properly.
Member
GS 160 Mk.2
Joined: 21 Oct 2013
Posts: 22
Location: East Sussex, UK
Thu Jan 09, 2014 9:09 am quote
GS 160 Points Timing -Help please !!!
Thanks blackbart. Can you tell me if the points cam can become misaligned, to affect the timing, even if it is facing out correctly?
I can see a groove so, if it's not a daft question, are there two woodruff keys on this side of the crankshaft, one for the points cam and another for the flywheel centre piece/hub?
Hooked
SS-180 x 1 (dead) SS-180 x1 (3'rd times the charm)SS-90 x 1 GS-160 MK1 x 1 P-200e x1 TV 175 S2
Joined: 26 Nov 2008
Posts: 237
Location: San Diego, California
Thu Jan 09, 2014 6:29 pm quote
The GS -160 cam does not have the words "lato esterno" marked on it only the SS -180. The GS-160 cam slides over and past the woodruff key by just a hair. The only thing that keeps it aligned is the tight fit over the crank. The key way on the cam is used only to line up the cam in the proper position as it's being tapped lightly onto the shaft.

I pulled the points cam off my GS -160 and put a new crank in the motor, but forgot to mark which way the cam came off and as I previously stated it's not marked. I put it all back together and shot the timing with a strobe and noticed the stator was turned to its max stops. I then took the cam off and swapped it around and the stator was then in its normal position in relation to the three screws.

So in a nutshell I think your cam is in backwards. Turn it around and the stator plate will be in its normal position .

If I did not mention it, the GS -160 cam has a thin wire spacer that goes between it and the crank. The SS -180 has a flat spacer wider spacer. These parts are needed to maintain proper spacing between the cam and crank.
Member
GS 160 Mk.2
Joined: 21 Oct 2013
Posts: 22
Location: East Sussex, UK
Fri Jan 10, 2014 10:07 am quote
GS 160 Points Timing with Strobe
Thanks very much ktmdriver. That helps my comprehension a great deal.
You mention using a strobe - an instrument which I'm familiar with when it comes to a 4-cylinder car with a distributor. Could you please tell me the procedure to create marks that will be visible when the flywheel is in place?
Ossessionato
2015 GTS300, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4430
Location: San Diego, CA
Fri Jan 10, 2014 10:30 am quote
Good help on making timing marks, etc.
http://www.scooterhelp.com/tips/timing/points.timing.html
Hooked
SS-180 x 1 (dead) SS-180 x1 (3'rd times the charm)SS-90 x 1 GS-160 MK1 x 1 P-200e x1 TV 175 S2
Joined: 26 Nov 2008
Posts: 237
Location: San Diego, California
Fri Jan 10, 2014 4:23 pm quote
Follow the link that sdjohn provided. It's the best resource out there. The only thing I do differently is power the timing light with a separate 12v source.

Be careful when hooking up the spark plug wire sensor and be sure it doesn't get pulled into the fan when the motor is running.

Make you marks using a Sharpie marker so they are easily seen when shooting the strobe light.

On the GS, keep the hub on and just take the three fan bolts off when adjusting the stator plate. It makes things easier. Just make sure you mark the fan and hub and line that back up each time.
Molto Verboso
Vespas 1964 GS160, 1965 SS180, 1977 V9A1T, 1983 PX150E
Joined: 16 Apr 2011
Posts: 1475
Location: Siam
Tue Jul 28, 2020 8:09 pm quote
This is a mark on the flywheel hub of my GS160. It appears to be factory inscribed and not something that someone scribed in. Iím assuming itís a timing mark. Could it be a top dead center mark or a before top dead center Mark?
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2329D116-49CA-4359-92ED-DFE623CD37E4.jpeg

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