1967 cb77 correct parts checklist

versuspop · Post by **versuspop** » Sun Jul 19, 2015 10:58 am

looking for some confirmation or if anything i mention is a red flag.
where do i buy OEM jets and needles?

here are the parts for my cb77 PW26 left side carb are these correct?
note: same setup on right EXCEPT the slide is a K2.0 PW26R

carb slide: K2.0 PW26L convex part toward air filters.
needle: K2423 (no 1 that i can see)
main jet: 135
idle jet:48 (actually left has no writing, but am assuming that it is same as right which is 48…i may have just answered most of my problem)
floats set from notch to 22.5mm- seem to not have any leaks.

needle set in center position. raising clip makes the mufflers backfire and overall performance gets worse.

Aftermarket dunstall replica mufflers
crappy metal pod filters
fully charged battery
fresh D8HA plugs.
compression in the 160s both cylinders
needle jets seem round
timing is dead on

bike falls flat around 4000rpm.

I am experiencing the seemingly common problem of over rich symptoms with the carbs. i have not found a post that identifies a definitive solution. the bike starts fine mostly without choke. definitely NOT cold blooded start.
idles mostly fine. rpm tends to dip and try to sputter dead after a bit. i am attributing that to the point where the plugs are fouling. fouling dry black.

VP

R100 · Post by **R100** » Sun Jul 19, 2015 12:15 pm

Stock main jet is 135, stock slow jet is 42.
22.5 is correct for the float height.
Don't recall for certain, but quite sure stock needle clip position is in the middle.

48lesco · Post by **48lesco** » Sun Jul 19, 2015 8:52 pm

I agree with R100 and the HONDA shop manual. #135 mains and #42 pilot jets. #48 pilot jets are too big. Can't expect factory performance with pilot jets that are 15% too big. Float height is 22.5mm and should be measured as I think you have from the cut-out in the lip to the edge of the float. The tang should just be touching the needle, not depressing the spring-loaded tip at all. The needles should be stamped 24231 sometimes the 1 is barely there. The needles usually don't wear. The shop manual says the clip should be in the middle groove. However, reputable opinions on this forum have been to have it one notch leaner. Either way it should run. Most of all, I would ensure that both carbs have identical HONDA brass. What do you mean by "falls flat?" That might sound more like an ignition problem than carburetors. Is it 4000 rpm in the driveway, or under load? Bring that thing up to Cleveland and we'll go over it.
-48

G-Man · Post by **G-Man** » Mon Jul 20, 2015 3:30 am

Here is the official Honda (UK) carb setting guide. A 48 pilot is much larger than a 42 as the Keihin jets are numbered for diameter not area like most carbs. Those pilots actually flow 30% more......

G

LOUD MOUSE · Post by **LOUD MOUSE** » Mon Jul 20, 2015 7:25 am

Somewhere in my HONDA service advisory pages HONDA recommended the clip of the CB/CL77 carbs was to be installed on the Second from Bottom slit. ..................lm

G-Man wrote:Here is the official Honda (UK) carb setting guide. A 48 pilot is much larger than a 42 as the Keihin jets are numbered for diameter not area like most carbs. Those pilots actually flow 30% more......

G

48lesco · Post by **48lesco** » Mon Jul 20, 2015 8:09 am

My bad, one notch richer from the middle clip position (needles raised) is what I've read here probably from a previous LM post. Luckily, it's not that hard to change the clip position, so you can experiment a little.

versuspop · Post by **versuspop** » Mon Jul 20, 2015 9:56 am

thanks guys.

I am going to try to find matching slow jets first. I will also put the needle clip in the proper position.

VP