CB750, the project begins.

[matt365]

I figured I would start a thread to document my current project.  Some of the pictures have been posted up in the new member intro thread, but I'm sure I'll run into some snags along the way, so I'll start her up anew.

Excuse the quality of the pictures.  They are all from my phone

Well, here's how I got her.  15,000 km on the clock, and older than me.  1978 CB750ss.
I trailered her home, and winterized it.  I took out the battery, side panels, pod filters, and sprayed rust proofing on EVERYTHING...  I hate storing a bike outside, and I didn't want it to corrode at all, even though it was tarped to hell and back.


I have a second set of carbs that I decided to give a once over to.  I took them apart (on the kitchen table...) and put all the jets & needles in carb cleaner and soaked the carb bodies.  I'm going to use the best parts from the 2 sets to make one good set of carbs.  I need some new jets though.  I've got pod filters, and a wolf exhaust with no baffles, so she's breathing pretty free.


I had the side panels in the car, and accidentally stepped on the one.  It was cold, and the material is real brittle; I split it nearly in half.  I melted the cracks together with a soldering gun, and I'll reinforce the back with screening and use a plastic repair kit to fill the front crack. 


I've got a second set of comstars that I don't really need.  The lips on the rims are a little dinged, but it would be cleaned up fairly easily.


I got a Kawi H2 replica seat from Pat Cowan.  He does excellent fiberglass work, and he is only across town from me in Georgetown, so it was extremely convenient.  I'm thinking gloss black, but I'm open to opinions.


I couldn't leave well enough alone, so I took the bike over to my grandmothers garage (I know...  I know... but I don't have a garage right now, and what is family for.  My 929 is stored there for the time being as well.)  I started ripping it apart.  I took off the exhaust, and I will get it sandblasted and I'll re-coat it with high heat header paint & then I'll wrap the headers.  I want to figure out something for a baffle though.  It is a wolf pipe (I think) and it appears it had a baffle in it at one time.  Any ideas on that one?


I wanted to check out the seat and see what I would have to cut up from the tail.


the shocks were way too stiff, and had no play at all, so I knew they need a good cleanup.  I dissassembled them and took the surface rust off with a 3M rust removal disk.





The front forks were a little rusted under the headlight brackets, and they had some light pitting.  The rust removal disk made short work of that.  I've got to put a set of progressive springs in, but when checking the manual, it states to use a good 10w-30 oil in the forks...  I would much rather use a quality fork oil.

What is suggested for stock valving CB750 forks? 

[Tim]

Nice starting point - looking forward to seeing the progress.  Smart move getting it into a garage.

Dumb question - how did you take the rear shocks apart?  I have a set of Hagon shocks that I want to clean up, but can't sort out how to get the retaining ring off the top end.

[TonUpSoldier]

good question..i have some stockers that i wanna clean up...i know they have to come apart somehows..do tell do tell..

[Shooter]

The rears springs can be diss assembled by compressing the spring .   I did mine in a vice by hand without special tools and re assembled the same way.   Do this on the "soft setting" of the spring.

The split retainers come apart.  The complete circle ring  lifts up so the split one can be removed from the shaft.

Hope this helps - more difficult to explain  than to do. Check the photos

[Ease]

The rears springs can be diss assembled by compressing the spring .   I did mine in a vice by hand without special tools and re assembled the same way.   Do this on the "soft setting" of the spring.

The split retainers come apart.  The complete circle ring  lifts up so the split one can be removed from the shaft.

Hope this helps - more difficult to explain  than to do. Check the photos

Be careful anyone else trying this. I have an uncle that lost an eye due to not using a proper spring compressor.

[hahnda]

In a pinch I have taken a few long  heavy duty zip ties and wrapped them around a couple of coils while the shock is on the bike. Sit on the bike to compress and tighten up the zip ties. When you get off the springs are still compressed. Make sure you use decent ties so they dont break.

[Mossy21]

Hey matt365, You need to visit this site  http://forums.sohc4.net/index.php
Lots of parts and great people. 

[matt365]

The rears springs can be diss assembled by compressing the spring .   I did mine in a vice by hand without special tools and re assembled the same way.   Do this on the "soft setting" of the spring.

The split retainers come apart.  The complete circle ring  lifts up so the split one can be removed from the shaft.

Hope this helps - more difficult to explain  than to do. Check the photos

I just pushed down on the springs with all my might and had my girlfriend drop out the retaining ring.  The second one was the difficult one... in the before pic you can see that the lower ring is locked into place on the shaft body...  the spring was compressed, and was much harder to get off.  I had to slide down the bump stops, and get a screwdriver against the top shock mount, and lever the spring down enough to get the retainer off.   I kept thinking it was going to spring up like a bear trap and take out a finger

I wouldn't even attempt it this way with a mono-shock, but the twin shock setup on the ol' CB was pretty easy (relatively...)   

The crome was starting to peel on the inside of the lower ring on the stuck shock; that coupled with the surface rust had her hung up pretty good. 


So, anyone know what weight fork oil I should use instead of 10w-30

[matt365]

Hey matt365, You need to visit this site  http://forums.sohc4.net/index.php
Lots of parts and great people. 

Thanks Mossy, I'll check it out for sure

[matt365]

Finally, a project update.  I've got the shocks all cleaned up, painted, and re-assembled.  They look almost brand new

[Tim]

Nice looking shocks - I just got finished the same sort of job on my Hagons.  What paint did you use?  I used Tremclad Automotive in black, a bit glossy.  Put a bunch of coats on.  I ended up having to order new springs as mine were mis-matched and needed to be chromed.  Chroming is as expensive as a new set of springs anyhow.

[shoe48]

I found the Shock tool needed to do this on Ebay for like 35.00 , it is progressives hand crank version , Might be cheaper than an eye ? 

[Tim]

Turns out it's not so difficult or dangerous.  I put the bottom of the shock in a vice, pulled down on the spring with both hands (leather gloves) and my wife put the retaining ring in place with needlenose pliers.

The spring is not under such tension that it's going to explode into motion if you let go, or when you relieve the resistance when removing the retaining ring.  You have to compress it about an inch or so.

The tool would be great, and I bought spring compressors from Princess Auto for $10 that turned out to be WAY too big for motorcycle springs.  But, at least for single spring shocks like Hagons, even with brand new 20 pound springs it's not that hard to do it by hand, so long as you have 4 hands working.

[Shooter]

"Turns out it's not so difficult or dangerous. "  ..... as we tried to tell you. 

anyway ....Its only kinky the first time.

Pleased you got it done .   

[matt365]

Nice looking shocks - I just got finished the same sort of job on my Hagons.  What paint did you use?  I used Tremclad Automotive in black, a bit glossy.  Put a bunch of coats on.  I ended up having to order new springs as mine were mis-matched and needed to be chromed.  Chroming is as expensive as a new set of springs anyhow.

I used Tremclad flat black rust paint.  I used motomaster metal surface primer first though.  I've got boxes of spray cans that I'm trying to finish up, so I'm using whatever I've got handy. 

I'd really like to powdercoat the frame and swingarm, but I think I might just take off the surface rust and hit that with a spray can too.

I'll use a quality Urethane based paint for the tank, panels, and seat, but the small stuff will most likely be spray bomb.