I haven't put a timing light on flywheel to verify, but I'm assuming a MC21 will make full power in 1st through 3rd gear WITHOUT the wire splice mod. The wire splice mod just tricks CDI into thinking it's in 3rd gear timing map all the time?

Also, the GPS wire mod is now considered not necessary. Why is that?

Great forum by the way! Looking forward to chatting and keeping these bikes running well and on the road/track!

Hey mate. From my understanding, the GPS splice is to allow more ignition advance in 4th, 5th and 6th. PGM has different ignition curves for each gear. 1st and 2nd are considered too advanced for high load (4th 5th 6th) but 3rd is a safer option.
The PGM splice (where you give 12v to the orange wire from the black wire from memory) keeps the power valve open all the way to redline. From factory the PGM closes the valve at 10000rpm (or there abouts) to choke the engine and limit performance to meet the standard when the bike was made.
So the PGM splice will give full power every gear.
The GPS splice will give more power in 4th 5th and 6th. 1st 2nd 3rd remain unchanged.
You need to do both to get the absolute best.
NB you need to be using GOOD fuel if you are to do the PGM splice. 98RON or better or you may detonate the engine in higher gears.
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Just do the orange/blue wire-splice. The GPS splice has been obsolete for almost 20 years.
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Andy.
NSR-WORLD.COM

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Just curious as to why the GPS splice was once a thing to do, and now it's not?

Because back then we didn't know that the orange/blue spice works in exactly the same was as the HRC delimiter!
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Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

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