Author Topic: CB750K0 to K6 tach cable route and length? (Read 5235 times)

MCRider · « **on:** November 17, 2011, 08:22:25 PM »

Could someone tell me the proper routing for the tach cable on a CB750? Mine is grey, meaning I cobbed it off some other model, and it runs up to the tach past the rear of the lower tree.

But MotionPro sent me a real long one, which I've since sent back to have shortened like the grey one. But the more I'm looking at pictures, it seems maybe they were right. Does the tach cable go below and then up the front of the lower tree?

CycleRanger · « **Reply #1 on:** November 17, 2011, 08:30:42 PM »

For the F or the K2? The shop manual has a page that show cable routing.
Here's for the F.

I wish someone would make a PDF of the 750 dealer set-up guide.

MCRider · « **Reply #2 on:** November 17, 2011, 08:33:51 PM »

Geez, I should know better, the K2. Mine looks like the F drawing. Put pictures I see of Ks in the gallery have it looping around the bottom front of the lower tree. Can't get a real good closeup though.

MCRider · « **Reply #3 on:** November 17, 2011, 08:48:19 PM »

My Clymer doesn't show. But my "Original Honda CB750" by John Wyatt does show. The tach and speedo cable meet and are held in place by a clip on the right side fork clamp bolt. The tach cable does come in front of the lower tree. But it makes a pretty severe upward bend at the tree.

The problem with all the pictures is that area is in the shadow and its hard, but I made it on that one picture.

Now I know I ran the shorter cable for many years so it must be all right, but different than stock. I owe Motion Pro an apology.

CycleRanger · « **Reply #4 on:** November 18, 2011, 07:19:19 AM »

Quote from: MCRider on November 17, 2011, 08:48:19 PM

My Clymer doesn't show. But my "Original Honda CB750" by John Wyatt does show. The tach and speedo cable meet and are held in place by a clip on the right side fork clamp bolt. The tach cable does come in front of the lower tree. But it makes a pretty severe upward bend at the tree.

The problem with all the pictures is that area is in the shadow and its hard, but I made it on that one picture.

Now I know I ran the shorter cable for many years so it must be all right, but different than stock. I owe Motion Pro an apology.

Yeah, the stock tach cable is pretty short, 20-24 inches or so.
That cable goes through the wire guide that is attached to the horn as well.

MCRider · « **Reply #5 on:** November 18, 2011, 07:36:08 AM »

Quote from: CycleRanger on November 18, 2011, 07:19:19 AM

Quote from: MCRider on November 17, 2011, 08:48:19 PM
My Clymer doesn't show. But my "Original Honda CB750" by John Wyatt does show. The tach and speedo cable meet and are held in place by a clip on the right side fork clamp bolt. The tach cable does come in front of the lower tree. But it makes a pretty severe upward bend at the tree.

The problem with all the pictures is that area is in the shadow and its hard, but I made it on that one picture.

Now I know I ran the shorter cable for many years so it must be all right, but different than stock. I owe Motion Pro an apology.

Yeah, the stock tach cable is pretty short, 20-24 inches or so.
That cable goes through the wire guide that is attached to the horn as well.

Yeah I know the cable is short. The question is "how short"? The one they sent me was 27". It was from their "stock". Cables that they are confident that they have good lengths on. Which is why I hated toi call them on it. It would have to have looped in front of the loewr tree, which just seemed to me to be outrageous.

The cable I'd used for 10+ years was 24". But its grey so i know its not original. So I sent that to them and told them to cut the 27"er down to 24.5". I want to be able to report back to them, but i don't want them to change their database if i have been using a too short (from stock) cable.

I'm going to look for more pictures in the forum. Wish someone would measure theirs and let me know the length and routing. CB750K0-K6

MCRider · « **Reply #6 on:** November 18, 2011, 07:54:47 AM »

Here, in 1986 or so, we can see the grey tach cable, routed to the rear of the lower tree.

Seems, OK. I'm right AND MotionPro is right. They are more right. But I like my way better.

Still I'd like to hear from someone with a stock setup.

RustyJC · « **Reply #7 on:** November 18, 2011, 08:06:14 AM »

Here's my K1, if you can make out what you need.

Rusty

MCRider · « **Reply #8 on:** November 18, 2011, 08:09:59 AM »

Thanks Rusty. i'd say that clinches it. Definitely goes below and then up the front of the lower tree. Thanks!

PS: I didn't think the K1 had the grabrail and long turnsignal stalks? Did you ad those?

RustyJC · « **Reply #9 on:** November 18, 2011, 08:25:07 AM »

Nope - that's the way it came out of the crate when I bought it at Jim Hall Honda in Houston in the summer of 1971. Here's what it looks like now:

Rusty

CycleRanger · « **Reply #10 on:** November 18, 2011, 08:27:33 AM »

Quote from: MCRider on November 18, 2011, 07:36:08 AM

Yeah I know the cable is short. The question is "how short"? The one they sent me was 27". It was from their "stock". Cables that they are confident that they have good lengths on. Which is why I hated toi call them on it. It would have to have looped in front of the loewr tree, which just seemed to me to be outrageous.

The cable I'd used for 10+ years was 24". But its grey so i know its not original. So I sent that to them and told them to cut the 27"er down to 24.5". I want to be able to report back to them, but i don't want them to change their database if i have been using a too short (from stock) cable.

I'm going to look for more pictures in the forum. Wish someone would measure theirs and let me know the length and routing. CB750K0-K6

I have an extra stock cable. I can measure it after work today. I can take a better picture of the cable on my K5 for you too.
It was cold and I was too lazy to go out to the workshop last night.

MCRider · « **Reply #11 on:** November 18, 2011, 08:33:12 AM »

Quote from: CycleRanger on November 18, 2011, 08:27:33 AM

Quote from: MCRider on November 18, 2011, 07:36:08 AM
Yeah I know the cable is short. The question is "how short"? The one they sent me was 27". It was from their "stock". Cables that they are confident that they have good lengths on. Which is why I hated toi call them on it. It would have to have looped in front of the loewr tree, which just seemed to me to be outrageous.

The cable I'd used for 10+ years was 24". But its grey so i know its not original. So I sent that to them and told them to cut the 27"er down to 24.5". I want to be able to report back to them, but i don't want them to change their database if i have been using a too short (from stock) cable.

I'm going to look for more pictures in the forum. Wish someone would measure theirs and let me know the length and routing. CB750K0-K6

I have an extra stock cable. I can measure it after work today. I can take a better picture of the cable on my K5 for you too.
It was cold and I was too lazy to go out to the workshop last night.

Thanks CR! I'd really like to know so I can put this issue to bed. No hurry, now that i know someone is on it.

MCRider · « **Reply #12 on:** November 18, 2011, 09:09:31 AM »

Rusty: I'm not being difficult here, just talking. As many issues have arisen we learn that Honda tended to just throw modifications at bikes "mid-model". I bought a new K1 in April of 1971. it did not have the grabrail and the turnsignals were mounted on short stalks making them much closer to the frame/centerline.

Looking at the profile shots in my Honda (official) Identification Guide, the K1 did not have the grabrail and the signals were as i described. BUT...

I look at the partsfish at motogrid.com, the grabrail is shown! But, there is no reference to it in the parts list, at all. i was hoping it might give a VIN number where the change was made. I thought is was a K2 change. (I owned a K2 also, current bike)

Looking at the K2 microfish, the grabrail is also shown. The part number is a "341" which is a K2 number. "300" was the K1.

No big deal, just one of those curiosities.

RustyJC · « **Reply #13 on:** November 18, 2011, 09:20:55 AM »

No offense taken at all. Perhaps mine was late enough in the production cycle (no pun intended) that some of the K2 stuff made its way onto it. Other than that, I really don't have an explanation.

The last 7 digits of my VIN are 1065518 if that helps.

Rusty

MCRider · « **Reply #14 on:** November 18, 2011, 09:27:22 AM »

Rusty: I'd need better source material. Your number is definitely K1, as are many other parts of your bike. (Your instruments have the idiot lights inside of them?)

The K2 didn't come out till March 1972, so "mid-summer" really isn't late. Mystery.

RustyJC · « **Reply #15 on:** November 18, 2011, 09:30:38 AM »

Quote from: MCRider on November 18, 2011, 09:27:22 AM

Rusty: I'd need better source material. Your number is definitely K1, as are many other parts of your bike. (Your instruments have the idiot lights inside of them?)

Yep, the idiot lights are in the instrument faces. Strange that the K2 stuff would find its way onto mine almost a year early.....

Rusty

MCRider · « **Reply #16 on:** November 18, 2011, 09:56:08 AM »

Yup. I like your mods, low bars, dual discs, 4-1, etc. My K1 was red also. Loved it. i was a teenager. Totalled it shortly after i bot it. Attempted to spin the tire and it got away from me. Mostly cosmetic. Cobbled it back together, rode it to FL for the winter, worked in a shop, converted it to cafe in my avatar. Rode back to indy. It was stolen by july 1972. No insurance.

RustyJC · « **Reply #17 on:** November 18, 2011, 10:23:21 AM »

I guess my bike represents the early 70s version of a streetfighter - drag race from stop light to stop light. The mods are from around 1972 - drag bars, Yoshimura double disc kit, Yoshimura Road cam & kit, Lockhart oil cooler, 17 tooth countershaft sprocket, Jardine 4 into 1, K&N filters, forgotten brand capacitive discharge ignition using the stock points to trigger (visible behind top of right rear shock), TT100 tires (now replaced but in the 1st photo of the bike without tank). I haven't made any attempt to bring the bike back to stock - it's a "period correct" survivor, I suppose.

Rusty

MCRider · « **Reply #18 on:** November 18, 2011, 10:34:48 AM »

Quote from: RustyJC on November 18, 2011, 10:23:21 AM

I guess my bike represents the early 70s version of a streetfighter - drag race from stop light to stop light. The mods are from around 1972 - drag bars, Yoshimura double disc kit, Yoshimura Road cam & kit, Lockhart oil cooler, 17 tooth countershaft sprocket, Jardine 4 into 1, K&N filters, forgotten brand capacitive discharge ignition using the stock points to trigger (visible behind top of right rear shock), TT100 tires (now replaced but in the 1st photo of the bike without tank). I haven't made any attempt to bring the bike back to stock - it's a "period correct" survivor, I suppose.

Rusty

I was trying to place the pipe. Most survivng Jardines are 4-2. The Jardine 4-1 wasn't as attractive to many as the RC pipe, but was a (the?) top performer. Nice to see a survivor in such nice condition.

Hinomaru · « **Reply #19 on:** November 18, 2011, 11:43:05 AM »

Quote from: MCRider on November 17, 2011, 08:22:25 PM

Could someone tell me the proper routing for the tach cable on a CB750? Does the tach cable go below and then up the front of the lower tree?

It sure does and can be seen in the attached photo. After passing thru the lower tree cable guide, the cable continues its upward routing along the right side recess of the stock headlight bucket and then finally connecting to the tach.

For some reason or other Honda decided to supersede the original K0 thru K6 tach cable part number from 37260-300-000 to 37260-449-840. If there is a difference in length between the two part numbers, I wonder which one Motion Pro is using for stock replacement?

Click for a larger view:

MCRider · « **Reply #20 on:** November 18, 2011, 12:20:27 PM »

Thanks Hinomaru! Amazing references as always. I had asked for a K2 cable. When I got it and it was so long (27") compared to what I'd been using, I didn't really try to see how it may go. If I had, I might have seen that routing it in front of the lower tree would work. But I kneejerked and just said no-way and sent it back. I see now how it could have worked. But compared to how I'd been routing it, I prefer my method. I may have gone that way 21 years ago when I added the oil cooler and the steering damper and had to go higher and shorter with the cable. Being that its grey, I'll bet I went down to the local salvage yard and got it. Its probably off of a CB350/360 or such. They've got tons hanging on the wall. The ends are all the same, its just the length and colors that were different and where they put the extra abrasion guard.

As to the part number change, "449" is the product code for the CX500 which didn't come out till 1979! So, don't ask me!

CycleRanger · « **Reply #21 on:** November 18, 2011, 05:27:10 PM »

The original (afaik) cable that I took off the bike is about 25 inches long.
The new Honda cable on there now appears to be the same length.

MCRider · « **Reply #22 on:** November 19, 2011, 04:59:33 AM »

Thanks CR. The 27"er sent by MotionPro is just too long then. It would really stick out. So I'll see what they send me.

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Author Topic: CB750K0 to K6 tach cable route and length? (Read 5235 times)

Hinomaru