Author Topic: Removing the engine 1978 cb750k  (Read 2363 times)

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Offline Dime

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Removing the engine 1978 cb750k
« on: October 03, 2024, 04:26:00 PM »
There were a couple of old posts about removing the engine with a length of pipe, ratchet straps and car jack stands. This sounded good to me but I modified the idea slightly.

What I used was a 6ft length of 1"×1"×1/8" square tubing. Two ratchet straps wrapped around the rotor cone and the points cone and over the tubing. Sturdy kitty litter pales. Some blocking and two scissor Jack's.

The picture of it setup is the mock up. I lowered the blocks of wood flat and bought another scissor jack off market place with a 4 inch wide base. I then added a 4 inch wide plate to the bottom of the other jack and made some channel out of 1 1/4"×1 1/4"×1/8" square tubing. Then I welded the channel on the top of the scissor Jack's.

At this point everything went very smooth. I could easily raise the engine by operating the scissor jacks evenly.

This is all done with the bike on the center stand. I just wiggled the frame to the left away from the engine.

Once the engine was out I used my bike jack to grab it and release the straps. Then lowering the engine.

Sorry I didn't take more pictures. I was solo and very concentrated on making sure this went well.

Here are a few pictures to give an idea. Oh and the little tool I rigged up for my drill to operate the jacks.

Offline Dime

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Re: Removing the engine 1978 cb750k
« Reply #1 on: October 03, 2024, 04:30:03 PM »
The jacks

Offline Dime

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Re: Removing the engine 1978 cb750k
« Reply #2 on: October 03, 2024, 04:31:02 PM »
How the jacks sit

Offline BenelliSEI

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Re: Removing the engine 1978 cb750k
« Reply #3 on: October 03, 2024, 05:56:58 PM »
I like it! Smart.

Offline HondaMan

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Re: Removing the engine 1978 cb750k
« Reply #4 on: October 03, 2024, 06:57:02 PM »
Nice way to do it!
Doesn't it make you want a ceiling-mounted cable trolley? ;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Dime

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Re: Removing the engine 1978 cb750k
« Reply #5 on: October 04, 2024, 03:33:11 AM »
Nice way to do it!
Doesn't it make you want a ceiling-mounted cable trolley? ;)
 

My wants are many but my realistic bank account says otherwise, LOL.

Offline HondaMan

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Re: Removing the engine 1978 cb750k
« Reply #6 on: October 21, 2024, 07:57:11 PM »
Nice way to do it!
Doesn't it make you want a ceiling-mounted cable trolley? ;)
 

My wants are many but my realistic bank account says otherwise, LOL.

Yeah, mine, too. I have a ceiling-hung block-and-tackle  for lifting up heavy stuff. For pulling-putting 750 engines I still use my old 'platform' approach of building a 10" high brick (or cement block, etc.) platform on the bike's right side. Then I remove the oil pan and pump (CB750) and bolt on a flat steel plate that I made to protect the gasket surface: it gives me another inch less engine height and makes things MUCH easier in-out. Then I don't worry about the engine sitting on the (protected by cardboard and ty-wraps) frame on the way out/in, which makes it just a 50-lb lift a couple of times, and 3 or 4 'wiggles' out-in.

Someone here invented a clever wooden "rotisserie hook" some years ago and sent me one to try out. It works great for raising the engine off the frame, but I don't have room to rig up his clever sawhorse-like supports on both sides of the bike, with a long 3" [steel?] pipe between them, so the engine can then just be lifted up and then slid out/in. I suspect Honda had something like that on the K1-K3 production lines. The K0 was uniquely loaded with the frame laying on its right side (engine also, in a wooden box below the frame) and the engine was then lifted up into the frame (from the reports I've seen years ago) and the 3 long bolts installed, then the frame was lifted and righted. The process at the Old Factory for the K1-K3 was said to be done with a hoisted engine brought alongside the (more completed than K0) frame with wheels, then a platform came up from below the frame, raising the engine alongside, and it was just pushed into the frame. Once in a while I've seen sideways marks on the oil pans that suggest the right-front-lower bolster hit it on the way in. After that I know the method changed again, but I never got to find out how it was done.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Dime

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Re: Removing the engine 1978 cb750k
« Reply #7 on: October 22, 2024, 01:12:13 AM »
Nice way to do it!
Doesn't it make you want a ceiling-mounted cable trolley? ;)
 

My wants are many but my realistic bank account says otherwise, LOL.

Yeah, mine, too. I have a ceiling-hung block-and-tackle  for lifting up heavy stuff. For pulling-putting 750 engines I still use my old 'platform' approach of building a 10" high brick (or cement block, etc.) platform on the bike's right side. Then I remove the oil pan and pump (CB750) and bolt on a flat steel plate that I made to protect the gasket surface: it gives me another inch less engine height and makes things MUCH easier in-out. Then I don't worry about the engine sitting on the (protected by cardboard and ty-wraps) frame on the way out/in, which makes it just a 50-lb lift a couple of times, and 3 or 4 'wiggles' out-in.

Someone here invented a clever wooden "rotisserie hook" some years ago and sent me one to try out. It works great for raising the engine off the frame, but I don't have room to rig up his clever sawhorse-like supports on both sides of the bike, with a long 3" [steel?] pipe between them, so the engine can then just be lifted up and then slid out/in. I suspect Honda had something like that on the K1-K3 production lines. The K0 was uniquely loaded with the frame laying on its right side (engine also, in a wooden box below the frame) and the engine was then lifted up into the frame (from the reports I've seen years ago) and the 3 long bolts installed, then the frame was lifted and righted. The process at the Old Factory for the K1-K3 was said to be done with a hoisted engine brought alongside the (more completed than K0) frame with wheels, then a platform came up from below the frame, raising the engine alongside, and it was just pushed into the frame. Once in a while I've seen sideways marks on the oil pans that suggest the right-front-lower bolster hit it on the way in. After that I know the method changed again, but I never got to find out how it was done.

Interesting stuff HondaMan. I am always on the lookout for alternative ways of  doing things. As Ecclesiastes said there is nothing new under the sun. Somebody has come across and dealt with it before no matter what it may be. That is one great benefit of the internet for sure.

Offline starf

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Re: Removing the engine 1978 cb750k
« Reply #8 on: October 22, 2024, 07:31:35 AM »
I did a little research on this topic before I took the engine out of my K7 last year.

The attached image was on an older post that I can no longer find - I take no credit for it. I ended up transferring it into CAD, cleaning it up a little, and having it manufactured locally. The horizontal piece strapped to the engine around the points cover and the stator cover. Then the hook is attached to a traditional engine hoist (I rented one for a weekend).

Take it slow (and use rags to protect the paint) and the engine will come out or in without any hassle. I did it solo, but a second pair of eyes wouldn't hurt.

Edit: Found the thread http://forums.sohc4.net/index.php/topic,58210.100.html
« Last Edit: October 22, 2024, 07:33:25 AM by starf »

Offline MauiK3

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Re: Removing the engine 1978 cb750k
« Reply #9 on: October 22, 2024, 07:42:41 AM »
I use the frame laying down method. Simple and only requires some blocking and padding.
The frame has to be pretty bare, only wheels, or not.
1973 CB 750 K3
10/72 build Z1 Kawasaki

Offline HondaMan

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Re: Removing the engine 1978 cb750k
« Reply #10 on: October 22, 2024, 10:55:55 AM »
I did a little research on this topic before I took the engine out of my K7 last year.

The attached image was on an older post that I can no longer find - I take no credit for it. I ended up transferring it into CAD, cleaning it up a little, and having it manufactured locally. The horizontal piece strapped to the engine around the points cover and the stator cover. Then the hook is attached to a traditional engine hoist (I rented one for a weekend).

Take it slow (and use rags to protect the paint) and the engine will come out or in without any hassle. I did it solo, but a second pair of eyes wouldn't hurt.

Edit: Found the thread http://forums.sohc4.net/index.php/topic,58210.100.html

I remember that one: I was thinking of having a local machine shop with their EDM make one for me when the wooden one arrived.
« Last Edit: October 24, 2024, 08:05:23 AM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline rotortiller

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Re: Removing the engine 1978 cb750k
« Reply #11 on: October 24, 2024, 03:24:49 AM »
I lay the engine sideways in a milk crate and install the frame to the engine. It takes time as is often the case with doing it the long way. It does reduce paint damage risk and nothing special is needed except time and patience. Because it is a hobby and not a production line (or expensive shop) it works for me. Those looking for time savers can cut frames and make hoisting jigs. These motors normally do not need to be pulled very often unless a fellow messes up on engine repairs due to haste etc lol. I have watched guys try to pull engines with the exhaust studs in place with the idea that the more parts left in place, the sooner they can get back to riding.

Offline HondaMan

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Re: Removing the engine 1978 cb750k
« Reply #12 on: October 24, 2024, 08:09:10 AM »
I have watched guys try to pull engines with the exhaust studs in place with the idea that the more parts left in place, the sooner they can get back to riding.

Yeah. :(
I've received some of those heads to repair. Those later heads need the studs of #1 and #2 removed for safest results. It can still come out, but it often either scratches the frame when the engine falls forward, or bends a stud - most often, the left-most #2 cylinder stud is what I've seen bent/broken.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline madmtnmotors

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Re: Removing the engine 1978 cb750k
« Reply #13 on: October 25, 2024, 04:17:51 AM »
I have watched guys try to pull engines with the exhaust studs in place with the idea that the more parts left in place, the sooner they can get back to riding.

Yeah. :(
I've received some of those heads to repair. Those later heads need the studs of #1 and #2 removed for safest results. It can still come out, but it often either scratches the frame when the engine falls forward, or bends a stud - most often, the left-most #2 cylinder stud is what I've seen bent/broken.

I usually remove the six exh studs for cyls 1 thru 3.
TAMTF...


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