Author Topic: Throttle Cable Routing '70 K0 (Read 1409 times)

Scootch · « **on:** May 27, 2022, 04:57:38 AM »

Does anyone have info and can point me to pics etc regarding throttle cable routing? I have searched but the threads I have found have pics that don't exist any longer.

69cb750 · « **Reply #1 on:** May 27, 2022, 07:33:23 AM »

The factory routed the cable through the triangle.
I prefer along side the top tube, sometimes this works, sometimes not, depends on tank shape which changed.

jlh3rd · « **Reply #2 on:** May 29, 2022, 05:18:04 AM »

this shows the cable routed on the left side of the neck...from there, don't know...

Scootch · « **Reply #3 on:** May 29, 2022, 06:04:18 AM »

Thank you for sharing some info. I will have to see what I can figure out bcz a couple of the cables take pretty sharp bends into the top of the carbs. However it's not clear if there is a better way...

newday777 · « **Reply #4 on:** May 30, 2022, 02:05:07 AM »

Quote from: Scootch on May 29, 2022, 06:04:18 AM

Thank you for sharing some info. I will have to see what I can figure out bcz a couple of the cables take pretty sharp bends into the top of the carbs. However it's not clear if there is a better way...

I saw a video of a bloke in England that had the tank off to bring a K0 back to life and the cables for the outer carbs were on the outboard sides of the frame to keep from sharp bends. I haven't had a K0 to verify it though. Have you been on the CB750 Sandcast/K0 only forum yet?

http://cb750sandcastonly.com/smf_forum/index.php

Scootch · « **Reply #5 on:** May 30, 2022, 04:34:58 AM »

Thank you for the additional info and the link to the Sandcast forum! No I had not been to that site or knew that it existed. I did find a pic or two there showing some of the cable routing at the carb tops. That is very helpful. I am still unclear what is meant by the "triangle". Supposedly there are excellent cable routing diagrams in the original CB750 green cover 1969/70 shop manual. I have seen references to that manual but do not have a copy.

69cb750 · « **Reply #6 on:** May 30, 2022, 04:57:10 AM »

Cable starts at right handlebar switch, goes through hole in tach and speedo bracket, comes down left side of frame neck, goes through frame triangle which is the bracket between top tube and lower two tubes, then to carbs.
Factory routed this way which results in some sharp bends to the carbs.
Sometimes you can route along frame top tube, it depends on the tank shape which changed in 69 and 70.

Scootch · « **Reply #7 on:** May 30, 2022, 06:13:34 AM »

Thank you for taking the time to provide additional information and description. Very helpful. At some point I will have to remove the tank and see what options are available. From what I can gather so far there really are no good options which is probably why the carb setup was quickly changed...

Scootch · « **Reply #8 on:** July 04, 2022, 11:35:55 AM »

So I got brave enough and finally today took a stab at taking a peek at the carb cable routing. I see what is meant by the "triangle". My cable is not routed through there. It is routed underneath it. I would prefer that it was routed through the triangle but probably not a major problem. However the #1 and #4 cables were routed underneath the frame bars instead of over them. This resulted in really sharp bends where the cables enter the carbs. I have now routed the cables over the bars. Throttle twist force seems reduced by about 1/2. I have not ridden the bike yet so keeping fingers crossed.

BenelliSEI · « **Reply #9 on:** July 04, 2022, 01:49:13 PM »

What I discovered last week on my ‘70 K0 was the shape of my tank is incorrect. The bike I restored came with all new Honda bodywork (everything painted red). But, I think the tank was a K1/K2 style. My Sandcast, and two other really old tanks I have, show four clearly marked dimples in the underside. This prevents the tank from pushing down on the cables (particularly the outer two). I managed to make it work, but I suspect that’s not what the original bike had......

What style is the underside of your tank? My old ones have four very clear recesses for cables.

Scootch · « **Reply #10 on:** July 04, 2022, 02:07:14 PM »

Once again today I forgot to take some pictures. I don't know the exact architecture of the underside of the tank but I think it something along the lines of the attached pic...

Bigmant · « **Reply #11 on:** July 04, 2022, 03:51:31 PM »

I have a ‘74, and had success routing both cables through the right side of the forks, and then through the triangle above the carbs. Haven’t had any binding issues so far!

Scootch · « **Reply #12 on:** July 04, 2022, 04:00:01 PM »

Quote from: Bigmant on July 04, 2022, 03:51:31 PM

I have a ‘74, and had success routing both cables through the right side of the forks, and then through the triangle above the carbs. Haven’t had any binding issues so far!

Good to know. Mine comes down the right side of the fork, under the triangle. Not sure why it was done that way. I am told that factory routing for mine should be on the left side of the forks and thru the triangle.

Bigmant · « **Reply #13 on:** July 04, 2022, 04:11:24 PM »

Quote from: Scootch on July 04, 2022, 04:00:01 PM

Quote from: Bigmant on July 04, 2022, 03:51:31 PM
I have a ‘74, and had success routing both cables through the right side of the forks, and then through the triangle above the carbs. Haven’t had any binding issues so far!
Good to know. Mine comes down the right side of the fork, under the triangle. Not sure why it was done that way. I am told that factory routing for mine should be on the left side of the forks and thru the triangle.

Someone here may know better than me, but given that the cables come off the right side of the handle bar, it seems like an extra long way to go to go down the left hand side of the bike. Unless of course you have cables that are TOO long.

BenelliSEI · « **Reply #14 on:** July 04, 2022, 04:20:36 PM »

Quote from: Scootch on July 04, 2022, 02:07:14 PM

Once again today I forgot to take some pictures. I don't know the exact architecture of the underside of the tank but I think it something along the lines of the attached pic...

If your tank looks like that, you have the xtra clearance for the carb top cables. Great!

newday777 · « **Reply #15 on:** July 06, 2022, 03:45:58 AM »

Quote from: Bigmant on July 04, 2022, 03:51:31 PM

I have a ‘74, and had success routing both cables through the right side of the forks, and then through the triangle above the carbs. Haven’t had any binding issues so far!

Did you go around the steering neck

Using stock height handlebar?
If not you should post pictures.

BenelliSEI · « **Reply #16 on:** July 06, 2022, 04:06:02 AM »

Quote from: Bigmant on July 04, 2022, 04:11:24 PM

Quote from: Scootch on July 04, 2022, 04:00:01 PM
Quote from: Bigmant on July 04, 2022, 03:51:31 PM
I have a ‘74, and had success routing both cables through the right side of the forks, and then through the triangle above the carbs. Haven’t had any binding issues so far!
Good to know. Mine comes down the right side of the fork, under the triangle. Not sure why it was done that way. I am told that factory routing for mine should be on the left side of the forks and thru the triangle.

Someone here may know better than me, but given that the cables come off the right side of the handle bar, it seems like an extra long way to go to go down the left hand side of the bike. Unless of course you have cables that are TOO long.

The original cables are long enough, and designed to go the long way around the headstock to ensure a gentle bend. Going the right side is too tight (and gets even tighter on right lock).

Scootch · « **Reply #17 on:** July 06, 2022, 06:57:14 AM »

This coupler is on the 1 into 4 throttle cable for the K0. Does anyone know if this can come apart? If it would come apart and be able to be put back together without causing a problem it would greatly simplify rerouting the cable.

Scootch · « **Reply #18 on:** July 06, 2022, 12:36:26 PM »

So I rode the bike today and the throttle effort is a lot less - probably half of what it was. The bike is so much more enjoyable to ride now.

BenelliSEI · « **Reply #19 on:** July 08, 2022, 05:18:40 AM »

You should try a Honda cable. They are much nicer than the aftermarket version.......

Scootch · « **Reply #20 on:** July 08, 2022, 07:11:15 AM »

Quote from: BenelliSEI on July 08, 2022, 05:18:40 AM

You should try a Honda cable. They are much nicer than the aftermarket version.......

Would you happen to have a part number that you can recommend?

BenelliSEI · « **Reply #21 on:** July 08, 2022, 07:32:11 AM »

I have one extra, will see what the bag has on it.

Don R · « **Reply #22 on:** July 08, 2022, 08:49:42 AM »

I carelessly routed my first K0 on the right side, in a parking lot I made a tight turn, the throttle cable had looped over the fork reflector and revved the engine. Thank goodness I had my hand on the clutch already.
That's when you know why Honda put the kill switch where it is and why they went to two cables.

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Author Topic: Throttle Cable Routing '70 K0 (Read 1409 times)