Author Topic: NEVER ANSWERED cb750K QUESTION FOR EXPERTS (Read 3303 times)

BenelliSEI · « **on:** March 04, 2019, 12:53:12 PM »

I’ve been reading this Forum for years. 5-6 weeks ago, I joined and my first post was about a cb750K design variance that has been bugging me for ages:

NEVER have I seen this particular design variance noted, photographed or explained. The left front engine mount (just below the exhaust port on the side with the kick stand) on almost all my SOHC cb750Ks is a cast lug, welded to the frame downtube. A bolt passes through it, and then into the main engine case (backed up by a captive nut). On my 1977 cb750K there is NO LUG on the frame. It has two small bushings welded through the frame. Attached by two bolts/nuts (that pass through the frame bushings) is a fabricated engine mount. At the engine end it uses the same “bolt to the main engine case”. Beautiful, separate bracket, see photo. As a BONUS, when removed, the engine tips forward a bit further, and is much easier to move in and out of the frame. EVEN STRANGER, my 1978 , goes back to the welded lug, just like every other K0-K6 machine. Has no one else ever noticed this single year modification? And why only on my 1977 cb750K7??

Every other minute change (even the most obscure) is documented in complete detail. Why not this one? Anyone?? I’ve never owned a cb750A. Did they have this?

scottly · « **Reply #1 on:** March 04, 2019, 01:30:29 PM »

All I can say is I have a '77K frame and it has the same motor mount as yours?

BenelliSEI · « **Reply #2 on:** March 04, 2019, 01:33:26 PM »

Scottly....... hopefully someone knows the answer. Driving me crazy!

Bankerdanny · « **Reply #3 on:** March 04, 2019, 02:11:18 PM »

My '78 F3 frame definitely has the lug, which I only noticed because of your previous post on this subject.

BenelliSEI · « **Reply #4 on:** March 04, 2019, 02:16:58 PM »

Mmmmmm? Wonder what a ‘77 F has??

robvangulik · « **Reply #5 on:** March 04, 2019, 06:14:40 PM »

Why does this bother you so much?
I had 2 k7's over the years, both with the 'permanent' brackets, but it wouldn't have made any difference for me if those lugs had been removable.

754 · « **Reply #6 on:** March 04, 2019, 06:27:38 PM »

Maybe its a knockoff frame ?

BenelliSEI · « **Reply #7 on:** March 04, 2019, 08:19:51 PM »

This is a standard change on all K7s. Just for one year. It “bothers” me because the smallest changes are all well documented, some ridiculously minor. But, nowhere have I seen this fairly major and obvious change documented. Honda usually made these improvements for a reason, and I’m not aware of any that were then reversed. Just curious......... and surprised there isn’t an answer!

754 · « **Reply #8 on:** March 04, 2019, 08:39:46 PM »

Only some K7 have that, from what I have seen..
On the sandcast they had a least 50 parts changes in the first 7400 bikes..
And not always documented

Don R · « **Reply #9 on:** March 04, 2019, 08:52:12 PM »

I have no answer but there wasn't going to be a 77 or 78K, only the F models. The US dealers had a cow because they felt they still had buyers for the K and Honda agreed to produce the k after all. Possibly it was an improvement that got added but the bean counters got it cancelled.
Often engineering and price point targets clashed. Many model change parts came and went as supplies of new/old were used up, especially in the K1 to K2 changeover. My brother remembers yellow body sets coming to the dealership he worked at to convert weak selling colors to brighter ones.

754 · « **Reply #10 on:** March 04, 2019, 10:45:13 PM »

Benelli.. did you check the parts book ?
Is the oddball mount shown.. ? If so, it likely lists the serial numbers that used it..
THAT is how I found out a lot about my sandcast, and what it SHOULD have, and WHAT it came with..

BenelliSEI · « **Reply #11 on:** March 05, 2019, 05:11:51 AM »

754...... good idea! Will do.

BrianAdair · « **Reply #12 on:** March 20, 2019, 05:52:18 AM »

Here is a picture of my K8, and K7, another thing is no weep hole on the back gusset.

20190320_073846 by Brian Adair, on Flickr

BenelliSEI · « **Reply #13 on:** March 20, 2019, 06:02:49 AM »

Brian....... thanks for sharing that, i’ll Chckthe “weep holes” next...... never noticed that difference. What’s the frame plate on your K8 about? Don’t think I ‘ve seen one there before??

BrianAdair · « **Reply #14 on:** March 20, 2019, 06:04:48 AM »

Quote from: BenelliSEI on March 20, 2019, 06:02:49 AM

Brian....... thanks for sharing that, i’ll Chckthe “weep holes” next...... never noticed that difference. What’s the frame plate on your K8 about? Don’t think I ‘ve seen one there before??

its just tire pressure and size tag.
edit*
It list more than that, I will get a better picture of the tag and post .

beemerbum · « **Reply #15 on:** March 20, 2019, 08:09:20 AM »

Quote from: scottly on March 04, 2019, 01:30:29 PM

All I can say is I have a '77K frame and it has the same motor mount as yours?

Same here

kmb69 · « **Reply #16 on:** March 20, 2019, 07:34:15 PM »

Quote from: 754 on March 04, 2019, 10:45:13 PM

Benelli.. did you check the parts book ?
Is the oddball mount shown.. ? If so, it likely lists the serial numbers that used it..
THAT is how I found out a lot about my sandcast, and what it SHOULD have, and WHAT it came with..

Frank, I looked when he first started this thread and could not find it in the parts books. Really weird!

754 · « **Reply #17 on:** March 20, 2019, 08:28:12 PM »

Wel, now that is very strange, as you can easily find at least 50 changes through the parts books on the sand cast 750.
And they missed a few there like the rubber oil line to braided switch.

To me this motormount and serial number pad change is clear evidence of at least 2 assembly lines...... I think..

BrianAdair · « **Reply #18 on:** March 21, 2019, 04:28:06 AM »

Quote from: BrianAdair on March 20, 2019, 06:04:48 AM

Quote from: BenelliSEI on March 20, 2019, 06:02:49 AM
Brian....... thanks for sharing that, i’ll Chckthe “weep holes” next...... never noticed that difference. What’s the frame plate on your K8 about? Don’t think I ‘ve seen one there before??

Here is a picture of the tag, sorry its a little hard to read, I couldn't get the lighting right.
20190320_221353 by Brian Adair, on Flickr

jlh3rd · « **Reply #19 on:** March 21, 2019, 05:28:49 AM »

is it this?

BenelliSEI · « **Reply #20 on:** March 21, 2019, 05:36:33 AM »

Jlh3rd....... that parts drawing is for the year in question (1977 cb750K7) but it shows the welded lug on the frame for the LF engine mount. The bracket used in that position does not show on that parts drawing.......

BenelliSEI · « **Reply #21 on:** March 21, 2019, 05:42:17 AM »

BrianAdair.......thanks for that photo! Never saw those plates on Canadian K7 or K8 but it has all the same information as the plate under the hood of my 1980 Ford F-350. I’ll bet the plate was a requirement there a few years before changes here....... learned something today!

jlh3rd · « **Reply #22 on:** March 21, 2019, 06:04:35 AM »

is it this....i know it says 79

robvangulik · « **Reply #23 on:** March 21, 2019, 08:17:39 AM »

That is a DOHC model, with the removable right bottom side of the frame.

Erny · « **Reply #24 on:** March 21, 2019, 09:21:55 AM »

In catalogue it appears ask K limited edition

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Author Topic: NEVER ANSWERED cb750K QUESTION FOR EXPERTS (Read 3303 times)