OEMSTD Carb Float height - carb frustration - CB175 K0

Cromwell

Cromwell

Well-known Member
Joined
Feb 10, 2022
Total Posts
81
Total likes
12
Location
Alberta, Canada
Just wondering if anyone can share the OEMSTD carb float height. I messed with the floats and didn't record the height. I am using (trying) them on a CB175 K0 with pods from Common Motorcycle Collective. I got the bike running initially but can't after adjusting the floats. I was getting carbon on the left spark plug and wet gas on the right when it was running and hence trying to adjust the floats. I reset the timing. I was also using 40 slow jet initially and changed to a 38. I could also use some help setting up these carbs if anyone has had success. I am on the verge of parking this bike for good if I can't solve this.
 
I've got two pairs of these carbs. All I did was swap the brassware for Keihin parts, ie 98 main and 38 pilot. I did not touch the float heights, I was impressed with the nylon floats and captive (Viton tipped) float valves. I recently had one carb flood on me, fuel pouring out of the overflow, but I put this down to dirt in the fuel. Dropping the float bowl and running some fuel out resolved that issue for me. I'd try resetting your float heights to original Keihin spec, which from memory is 21mm (not 27mm, as stated in the Haynes Book of Lies ).
 
Thank you so much Richard. I tried 28 and it was a no go. Tried 19mm as per the manual (CB160) and no go. I also tried 21 without success. My last attempt was 25. Still the same result - wet with fuel on the right and too rich on the left (carbon). What is your power air jet? The originals were not labeled. I did reset the timing so that should not be an issue. I am wondering if it is valves or something else. Any thoughts?
 
Power air jet ? I wonder if we are talking about the same carbs. Mine are 20mm chokes, vague recollection that the K0 engine had different carbs, 22mm perhaps ?

All this assumes that engine is mechanically OK, similar compression on both cylinders etc.
 
Since these have bowl drain screws, a piece of clear flexible tubing held alongside the bowl will show where the actual level is. 2-4mm below the bowl rim may be a good target level.

Sparkplug spark with plug threads laying on the cylinder fins?
 
Richard Pitman said:
Power air jet ? I wonder if we are talking about the same carbs. Mine are 20mm chokes, vague recollection that the K0 engine had different carbs, 22mm perhaps ?

All this assumes that engine is mechanically OK, similar compression on both cylinders etc.
Click to expand...
Power air jet is the large jet that points back towards the air box. This is the way they are referred to on CMSNL. Item 33.honda-cb175k0-super-sport-left-carburetor_bigma000169e16_461a (1).gif
 
ballbearian said:
Since these have bowl drain screws, a piece of clear flexible tubing held alongside the bowl will show where the actual level is. 2-4mm below the bowl rim may be a good target level.

Sparkplug spark with plug threads laying on the cylinder fins?
Click to expand...
The only problem with doing this is that the carbs are on an angle.
 
Cromwell said:
The only problem with doing this is that the carbs are on an angle.
Click to expand...
The mid line will still be a true value (median). I wish this value were given, experimenting to measure actual level would be tedious, with my shaky hands, partial immersion of float will cause some displacement.
My FSM lists the PK22 height of float at 19.5, even Clymer's agrees.
 
You could also drain the bowl and measure volumes. This will be lower than actual, due to displacement of floats and jets.

Consider yourself fortunate as my CA95 has PK20, without drain screws.
 
You must log in or register to reply here.
Back
Top Bottom