Did this mod to my 38mm butterfly Keihin carb today
#12
12-24-2013, 10:59 AM
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Looking forward to your report.
Slight thread hijack warning!
Does anyone have a good understanding of the various Keihin Carb's used on H-D's?
I've seen reference to 38 mm, 40 mm, 42 mm sizes in the past, and have done some searching, but I can't nail down exactly what exists, when/why, and the differences (Other than throat size.)
If there are several sizes, do you just measure the I.D. of the throat to distinguish them?
And my very basic understanding is that smaller throats give more precise control at lower rpm's , larger at higher.
But are specific sizes better for stock EVO's, bumped compression, upgraded cams, etc.?
You can slowly go nuts chasing leads on the 'net when researching this.
Slight thread hijack warning!
Does anyone have a good understanding of the various Keihin Carb's used on H-D's?
I've seen reference to 38 mm, 40 mm, 42 mm sizes in the past, and have done some searching, but I can't nail down exactly what exists, when/why, and the differences (Other than throat size.)
If there are several sizes, do you just measure the I.D. of the throat to distinguish them?
And my very basic understanding is that smaller throats give more precise control at lower rpm's , larger at higher.
But are specific sizes better for stock EVO's, bumped compression, upgraded cams, etc.?
You can slowly go nuts chasing leads on the 'net when researching this.
#13
12-24-2013, 12:57 PM
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Quick Note so as not to hijack…. get a copy of Donny Petersons Unauthorized Technical Guide to Harley Davidosn Volume III: The Evolution 1984-2000. Over 50 pages explaining them. Very well written. He also has 2 volumes out on the SAhovel era and is currently working on the panhead era.
Sometimes the answer is right under your nose and you are too stupid to find it. Christmas reading.
#14
12-25-2013, 03:47 AM
#15
12-25-2013, 03:48 AM
Quick Note so as not to hijack…. get a copy of Donny Petersons Unauthorized Technical Guide to Harley Davidosn Volume III: The Evolution 1984-2000. Over 50 pages explaining them. Very well written. He also has 2 volumes out on the SAhovel era and is currently working on the panhead era.
possibly the best books out there apart from genuine hd workshop manuals and the sleazyriders tips and tricks volumes 1 - 4
#16
12-25-2013, 06:45 AM
#17
12-25-2013, 08:16 AM
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I did a search and see reference to .pdf links but cannot find the links, .pdf's, or books. 1 volume is on Amazon, nothing else. .
Any help available? Thanks.
Last edited by RaSh; 12-25-2013 at 08:28 AM. Reason: Amazon reference.
#19
12-25-2013, 10:11 AM
#20
12-25-2013, 10:19 AM
The HS42 is configured to use the OEM air filter backing plate, and OEM throttle cables, which I think is a big improvement.
Last edited by Dan89FLSTC; 12-25-2013 at 10:23 AM.