Originally Posted by
Seagull 170
Before you follow zul8tr thoughts, who I'd guess is bang on the money, & build a dividing wall.
See if you can seperate the butterflys so that they are actuated by separate cables, if you have a spare carb.
Cable up one choke in the normal manner to give normal low & mid range performance, & the second to open when it starts to come on song, maybe 1000 revs below max, then open both together to find the limits on the second choke.
If the second choke is first tried on a lawn mower type throttle it's easy to find the start point.
I've seen this done on small single cylinders fishing motors with two seperate carbs both slightly smaller than the origonal, the second only opening almost at the previous peak revs, with a 10% gain in peak revs with the same prop.
This is another experiment where it would be good to have dyno at home.
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