Question becomes --
do you really need the pin on that first chain anyway?
Your OE original in the scoot has no pin and
you MUST remember to pull the cover around 10-15,000 miles to catch the extension at something greater than 15 but less than 20mm. If you don't, ya got no OEM pin to save your bacon 'cause Suzuki didn't put one in there.
This is the maximum danger zone
when you really did need the pin and you got no pin to back you up for any accidental laziness/indifference/ignorance on your part cause Suzuki didn't give you one.
When you put the slavy extension on to the steel slider and put it in your second hole position on that first chain, well then you don't need the pin because the chain will move forward until it hits itself
(whirrrrrrrrr!!!) and stop moving forward before the pin would ever hit the inside of the slot. Pin never gets used on the second life of the OEM first cam chain .... the chain "alarms" you itself. giving a strong audible tactile alarm it is time to replace the cam chain and the front side chain guide.
I guess the pin is there for insurance/reassurance that no matter what the spring can't get puked between the gears and give you the big crunch -- and that is reason enough I guess.
But I thought I'd bring the thought up for discussion purposes anyway. Point being the pin never gets used on that first cam chain, ever.
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Now, on that second cam chain, then yes it would be a good thing to have as you run at risk for remembering to pull the engine open and look at it after the first 10,000 miles after doing the new cam chain rebuild. A pin would be cheap good insurance for that first hole run on the new chain -- definitely worth having.