carburetor/throttle upgrade. oh yes, i went there...

G

gone_fishin

Guest
i think i may have stumbled upon the sophisticated grandpappy of the "happy time" carby.
this is uncannily close...off a 1978 honda express. matter of fact, it's so close i'm betting it'll work. carb w/choke, throttle w/choke, brake lever, killswitch, brakelight. what a tweak this is gonna be if i can pull it off.
41_MVC485F_1.jpg

like the "happy time" it has a mechanical idle-screw. it has a choke that (i think) affects only idle, an idle-mixture screw, & i'm
guessing it has mixture slots on the needle, too, because i can see the circlip. if i'm figuring this right, the express needed a LOT of rpm's to do 30mph, so i bet flow is already adequate, i'm not adverse to punching out the jet tho as last resort.
41_MVC486F_1.jpg


now that the chain tensioner is working right, i need something to do in the morning, so i'll tear it down and have a look.

at the very least i'll have a neat throttle assembly 8)

any info would be groovy :)
 

iRide Customs

Member
Local time
2:27 PM
Joined
Apr 27, 2007
Messages
893
Location
Oregon
Hmmm...that looks interesting. Are you going to bolt it right to the cyl. or will you need a new manifold? If you need a new manifold, I know someone who could make one for you :D
 
G

gone_fishin

Guest
it's almost the exact size as the stock carb, so bolting direct to the cylinder would jam it into the clutch cable.

first i'll just rig something up until i know it works, then we'll talk to your "friend" about a manifold, i hope he works cheap ;)
 
G

gone_fishin

Guest
wavygravy showed up just in time to run-get-me a piece of heaterhose & take some pics :)

41_MVC492F_1.jpg

41_MVC488F_1.jpg

41_MVC489F_1.jpg

will it?
41_MVC491F_1.jpg

it sure will!
41_MVC490F_1.jpg

:devilish: :devilish:

i'll keep yas posted 8)
 

srdavo

Well-Known Member
Local time
4:27 PM
Joined
Nov 4, 2006
Messages
3,150
Location
Pittsburg, Ks.
looks good.....what does the 2nd carb cable do? choke?? nevermind.... I see the choke lever on the grip.

performance??
 
G

gone_fishin

Guest
41_MVC493F_1.jpg


i have 187 miles on a roller-bearing "70"...running penzoil at 32:1...it's starting to kick in really nicely.

the happy time carb: predictable starts & reliable. sorta decent scoot up to 19-21 and it gets a bit flat...if i hold it at 90% throttle i eventually get 26-28mph on the level.

the ???shin carb: hard start, excellent scoot up to 20mph, then i have to feather it around 75% throttle but i get a strong 28mph cruise...this can only get better when i make a real intake and learn how to set it.

any advice or guidance on this carby?
 
G

gone_fishin

Guest
you know, 'kronic, i never thought i'd be messing around in here at all :LOL:

ok, back to the happy-time carb for now...i'll have to work on an intake & really get the new one clean and functioning right.

the honda throttle cable & cap fit right on the happy-time carby, too easy :)
 
G

gone_fishin

Guest
and i'm still goin' there!

a buddy offered to weld whatever i could come up with...waste not, want not ;)
 

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