Topic: 1978 CB750K front forks, need help.

[Griffinjc]

Hi all,

I'm new to the forum so I apologize in advance if this is a redundant topic. I've searched and googled but I just can't find the information I am looking for.

I bit the bullet and picked up a 1978 CB750K for a resto-mod project. I know very little about bikes mechanically although I have ridden and done some racing for a number of years. I figured this would make a fun project that I could learn alot from. So far I'm having the time of my life!

I have just finished the primary disassembly of the bike (basically bare frame, forks off, swingarm removed, engine and all electrics out, etc...) and I decided to start tackling the front suspension. I was able to disassemble the forks no problem and as described by a number of sources including this website (thank you for all the great info), a Honda factory manual which I found on here (again, thank you) and a Haynes manual. There was one small exception which I will get too.

The problem is that once I took it all apart there is virtually nothing that looks like these sources have described or shown in pictures. It's like the forks are from a completely different bike. The lower fork tube matches but all the internals are different.

To start there was no circlip on top of the fork seal at the top of the lower housing. There was another strange clip thing (pictures below) that came off no problem. once that clip was removed I unscrewed the allen key bolt at the bottom of the lower housing and slid the entire inner section off with no issues. That being said the seal did not slide off and once removed the inner housing, piston, and other internals just don't look right. I have about a third less pieces and the pieces I have don't match anything at all. Check out the pictures below. If anyone has any information for me I would really appreciate it. I did get a part number of the seal #354811 (my manual says it should 354611). The rest is a mystery.

Thanks for your time,


Sorry for the way the pics look, I had my prime lens on my camera so the depth of field is very narrow.

This is the clip that was under the dust boot above the fork seal.


This is the lower fork housing (looks normal to me)


This is th remainder of the internals that came out. This everything, there were no bushings or other clips of any kind.

[Jerry Rxman Griffin aka MuthaF'er]

Well Griff, all that looks pretty normal. I have 4 manuals and none are perfect for my bike. If you find one for ONLY a 78K well.... it won't happen. 78's were the last year and it's not like they did anymore manuals other than some updates. You've done well so far. Observe and think common sense when removing parts and comparing to the book. That clip is the circlip you've read about. That seal is not going to just jump out, it's kinda pressed in. Just be careful removing it and don't use a screwdriver and scratch the insides. When you reinstall a new seal it is generally recommended that the lettering is up. Tap it in with some PVC pipe. 1.5"(??). You can even do it with the tube in place which could prevent damaging the seal when installing the tube afterwards. 

Use Photobucket (free) to load images to then copy the "img" code and paste here. Full size and we'll be able to see them better and in more detail.

Such as

 

Ignore the 'extra' pieces you see such as the small PVC spacer for my aftermarket springs.

[HondaMan]

Well Griff, all that looks pretty normal. I have 4 manuals and none are perfect for my bike. If you find one for ONLY a 78K well.... it won't happen. 78's were the last year and it's not like they did anymore manuals other than some updates. You've done well so far. Observe and think common sense when removing parts and comparing to the book. That clip is the circlip you've read about. That seal is not going to just jump out, it's kinda pressed in. Just be careful removing it and don't use a screwdriver and scratch the insides. When you reinstall a new seal it is generally recommended that the lettering is up. Tap it in with some PVC pipe. 1.5"(??). You can even do it with the tube in place which could prevent damaging the seal when installing the tube afterwards. 

Use Photobucket (free) to load images to then copy the "img" code and paste here. Full size and we'll be able to see them better and in more detail.

Such as

 

Ignore the 'extra' pieces you see such as the small PVC spacer for my aftermarket springs.

Hey, Jerry:
Are those fork pieces actually laying on the CARPET?

[scottly]

Hey, Jerry:
Are those fork pieces actually laying on the CARPET?

Mark, did you miss Jerry's sig line about free at last? 

[Jerry Rxman Griffin aka MuthaF'er]

Yeah. Scottly has a point but.... it's just the living room carpet  and you have to keep in mind that stuff is all new/NOS except the valves and the old spring used for comparison. Even then they received a thorough cleaning in the parts washer. My guesstimate is the whole bike is now 90%+ new/NOS 

[Griffinjc]

Thanks for the quick reply and information. It defintely puts my mind at ease that my fork internals look normal. I will figure out the photobucket thing as well. I'm sure I'll be posting fairly frequently on here during my project.

As far as the seals go, with them stuck in the lower fork housing, what is the best way to get them out? Most of the info I have found simply says take them out to replace them or use the lower housing and bushings like a slide hammer to get them out. That doesn't seem to be the right fit for my current situation. Any thoughts?

Thanks again,