The governor cover? I assume you just mean the pump lid/top? It is the same gasket between NA and TD. The cold start o-rings are also the same.
Yes, the top lid cover apparatus. Throttle shaft comes up through it.
I'm sure i was wrong on the seal for that part now after kicking in more memory. (2 more tokes)
Leaving us to have to trim all those nubs off is SO unthoughtful.
On a whim - about 2 years ago i bought 3 of the 126 kits thinking as long as i wasn't doing the aneroids all the time - save some bucks. Got the 126's for $10 each. 121's cost me 18-24 depending which channel.
On the next Altitude pump, i used a 126 kit.
One of the cold start seals didn't seem exactly match,
winged it anyway.
It leaked on bench test.
Had to open a 121 kit and get the right seal for it.
Thats where that sentiment came from.
Worth noting these TD and Altitude pumps i've done all have had
the fast idle rod/spring feature on the cold start.
And worth noting i've never done a Non-Aneroid pump.
I'm "thinking" that might be what divides them.
Being whether or not they have that fast idle feature.
Or it was just a bad day.
But i use nothing but 121's on Aneroid pumps since then.
and BTW -
The Zexel Black seal is Bosch of Japan
The Bosch Brown Viton seal is Bosch of Germany
Might try putting these 20mm Bosch Brown seals on eBay some time for half price. lol
Damm guys wouldn't get hurt by swapping me the 17's !