Honda CB750 Sandcast

The Restoration Shop => Fuel (gas - petrol) Tanks, Side Covers and Air Box => Topic started by: Sgt.Pinback on February 26, 2014, 10:00:02 am

Title: K0 carbs - overflow tube?
Post by: Sgt.Pinback on February 26, 2014, 10:00:02 am
Had the K0 sand- or diecast those tube overflows? In some pictures I see them, in some I donīt.
My 12xxx diecast has none.

CMS says from 1029794 upwards

Guide for the overflow tube from 1068376 upwards

Is that correct?
Title: Re: K0 carbs - overflow tube?
Post by: Steve Swan on February 26, 2014, 11:39:26 am
to best of my knowledge, no sandcast had overflow tubes.   
Title: Re: K0 carbs - overflow tube?
Post by: corsa65 on February 27, 2014, 01:09:54 am
E 1682 has them. Cast date 5/23 but the frame 1630 has a date of 12/69 which might explain a late application. I just vapor blasted the bowls with good results. Don't tell me I have the wrong carbs. ???
Title: Re: K0 carbs - overflow tube?
Post by: Steve Swan on February 27, 2014, 09:27:19 am
what are both you referring to ?  float bowl OVERFLOW tubes ?    OR..... carburetor body VENTS ?  both can accommodate hoses.

pinback used the term OVERFLOW, which for me references the float bowl.  overflow is the Honda term used in parts books for the float bowl overflow tubes.

per Honda parts book, "overflow tubes" are not shown in the early 69 parts books.  in fact, the early books show no tubes for overflow but also no side vent tubes.  K1 parts books call for "overflow tubes" be used beginning E29,794.  Do either you guys have parts books to reference ?  the 71 parts book shows side vent tubes in the sketches, but does not reference the vent tubes with a description or a part number.



Title: Re: K0 carbs - overflow tube?
Post by: corsa65 on February 27, 2014, 10:15:12 am
You are right, I wasn't reading carefully. I was just thinking about the tubes. My carbs don't have overflows but they do have vent body tubes and these are not shown in my April 69 parts book either.
Title: Re: K0 carbs - overflow tube?
Post by: Sgt.Pinback on February 27, 2014, 12:55:06 pm
Thats exactly what I meant, Stefe. Tubes on those bowls.

16290-300-000

Shown in the parts list under cb750.  Not staed from which VIN unwards.
Title: Re: K0 carbs - overflow tube?
Post by: hondasan on February 27, 2014, 03:17:30 pm
Parts bulletin #750-30 (dated July 31 1970) states the Overflow Tube Assembly to have been applied form engine number CB750E-1029794.

Chris R.
Title: Re: K0 carbs - overflow tube?
Post by: Steve Swan on February 27, 2014, 07:27:33 pm
early carbs have horizontal brass tubes pressed into the carb bodies.  later carbs have cast 90' elbows.
Title: Re: K0 carbs - overflow tube?
Post by: Sgt.Pinback on February 28, 2014, 04:57:06 am
Thanks.