78 750 to 850cc Vintage Street / Track theme build

[one_civic]

So I have collected enough vintage parts and done my homework to finally start my build thread. This will be mainly my street bike with a vintage track bike theme.
In this thread, you will see lots of pics taken over the course of the last year ranging from rebuilding old Koni shocks to.....well you'll see.

So far this is what I have accomplished and some pics to compare them with. (Warning, 56K Beware) I bought this bike in excellent condition for $900 canadian from someone who paid much much more and invested a lot of time and money then finally said...... I've Had enough.

This is what the bike looked like when I picked it up 2 years ago, previous owner had done all the maintenance and it came with dyna green 3 ohm coils. It had intermittent spark which I traced down to the stock points and badly damage points condensor wire harness.

First thing I did was to install a Dyna ignition system and she fired right up, then replace the old tires with new sticky Pirelli Sport Demons and this is the way she stayed for the first year.

 

[one_civic]

Next on the to do list was to find a decent vintage pipe, It took me a while but I finally came along a group who race vintage bikes and put a wanted ad up on their forum for a 4-1 for my bike.
About a month and a half later, a racer who races in the VRRA (Vintage Road Racing Association)( http://www.vrra.ca/ ) sent me a pm with a nice old Yosh pipe that that been professionally repaired years ago and he was willing to part with. My inlaws picked up the vintage yosh pipe for me in hamilton as they live in toronto and I live in Ottawa and yeah, I was pretty stoked!

Christmas did come early for me that winter, lol

 

[one_civic]

As I am long term disability, I decided to volunteer my time as a track marshal at our local track to give back to the racing community and to get into motorsports. I love motorcycle racing and volunteer as many days as I can including the Canadian Superbike Championship ( http://www.csbk.ca/ ) at both Calabogie, my home track ( http://www.calabogiemotorsports.com/ ) and Mosport in Toronto ( http://canadiantiremotorsportpark.com/ ) Also Shannonville, ( http://www.shannonville.com/ ) Main home of the VRRA.

 

[Guest]

Curious about the " '78" 850, as they came out for the '79 model year. :-k

Possible that it was assembled in '78 as a '79 model? Check the date on the VIN plate.

You can't always go by what the title says, either. Title clerks/inspectors are known to look at the date on the VIN plate or even just copy what some previous clerk entered. It's not always obvious, but in this case, since there were no '78 850s, it kinda stands out.

 

[one_civic]

Last summer, it was time to update the suspension, I ordered some 1.0kg Sonic springs and through some searching and posting wanted ad's, found a nice old pair of Koni 76P-1296 Clevis to eye rear shocks.
Unfortunately I contacted Ikon for a build kit and was told that they are NLA. I was not going to give up that easily and really wanted to restore these shocks, here are some before pics.

If you look closely, I assume the spring colour is blue, blue, red, which means my springs are progressive and rate is 100/140/185 lbs/in. according to Koni's old chart, They also came off an older gs1100e, and are 0.5" longer than stock.

 

[one_civic]

phydeauxmutt The title says 78 750 to 850cc, I am doing an 850 swap, maybe I should clarify this before I post any further pics

 

[one_civic]

Anyways, on it was a tough time searching other forum's, ebay, etc. to find some new seals, here are the old ones compared to the new ones,

Old ones,

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New style ones,

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And the blueprint / dimensions of the old style

 

[one_civic]

I finally came upon a fellow named Robert Haag, who rebuilds / restores these old shocks and who bought up a bunch of NOS seals from a motorcycle store before they went under, he also sell's conversion kits which use the stock upper retainer but incorporate a brass bushing should you choose to convert to the new style seal.

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from my research though, the newer styler seals a little bit bigger for the older style shafts but Robert Haag has used them on the older style shafts without any issues,

I chose to buy a pair of his NOS top seals and found some viton top O-ring's from a local bearing supplier,

Robert Haag's email is

rhaagusa@yahoo.com

He is very helpful rebuilding these old shocks and can supply some NOS of the old seals as well as the conversion bushing / kit for the newer style

 

[one_civic]

First thing to do when disassembling these shocks is to either buy a pin spanner wrench or fabricate your own, I chose to make my own,

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apply a little heat to the top cap and as long as your pin wrench is the proper size or as I did, measure the pin hole diameter and use drill bits, the cap should come off exposing the top seal, washer, spring and O-ring.

After that, remove the shaft and piston from the tube which it rides up and down on

As you can see the piston is gummed up from old shock oil over the years, In order to remove the piston from the shaft, you must first remove the piston shaft rebound adjuster,

 

[one_civic]

Next, carefully unscrew the piston from the shaft without doing too much damage to the piston,

With the piston off the shaft, we can see how gummed up the ports are, I used brake cleaner, a small needle and some elbow grease to clean it up

Nice and clean

And most importantly remember the shim stack order of the piston and foot valve which I did not take pics of

 

[IanC]

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I spy a Gamma on a wall.
Looks like a nice project start point. Looking forward to more progress.

 

[one_civic]

Now these old shocks do not use gas pressure, they dampen by using oil aeration, therefore it is critical to get the proper amount of oil in each shock then compress them and make sure they are compressing at the same level, if not, remove top cap with your handy pin wrench tool and remove / add oil as needed.

If too much oil is added, the shocks will not compress, or one will compress more than the other. I added around 70-75ml of 10wt fork oil and that allowed both shocks to dampen / compress roughly half way before they would not compress anymore.

The one thing I did not (or forgot) to take pics of is the foot valve, which is the base of the shock, You can see the foot valve in Post #10, pic #1 on the right hand side, you will need a 1/4 7mm thin wall socket and a flat blade screwdriver to disaemble the foot valve.
Do not mess up the order of the foot valve shim stack unless you can find proper shims and know how to "fine" tune these older shocks.

 

[one_civic]

Here's what they look like with a little bit of Aluminum polish, some paint, new bump stops and eye bushings which are available in different sizes and can still be ordered through Ikon.

 

[one_civic]

I spy a Gamma on a wall.
Looks like a nice project start point. Looking forward to more progress.

The guy I bought the pipe off races a Gamma, unfortunately its not my garage, my garage is my finished basement right now

 

[one_civic]

So here she is at the end of last 2015 season

No garage to work in over the winter so no choice but to strip here down and bring everything into my finished basement, I have a very understanding wife, lol

 

[one_civic]

into the basement she goes

 

[steve murdoch]

Great resto on the shocks, Civic.
Will you be at Mosport in August with the VRRA?
A couple of us are hoping to ride up on the Saturday. Family holiday might bump this.

 

[one_civic]

Thanks Steve,

I don't think so Steve, my wife is due in June for our first, I will definitely be marshalling at shannonville for the 1st round of CSBK the may 24 long weekend, I'm pretty sure there will be a P4 round for the VRRA that weekend as well.
When they come in sept. to Calabogie, I'll be working that weekend for sure.

 

[one_civic]

So in order for the 83 850cc cylinder to fit my 78 750cc lower case, I had to remove material from cylinder's 1 and 4. Now I've talked to a few people claiming they did not have to grind anything on their upper case and their cylinder's fit fine, however this was not the case for me.

Here we can see that their is an approx. 10mm gap in order for the 83 850cc cylinders to fit.

Bella's head is holding up the upper case while I take this pic, lol

 

[one_civic]

And here is where the 83 850cc cylinder's bind in the upper 78 750cc case

And here in permanent marker on the back side (intake side if you will) of the upper case is where I grinded in cylinder's 1 and 4 for the 83 850cc cylinder to fit,

Now this is what I did, you may or may not have to do this procedure or may do it differently, but like I said, This is what I did. I'll let the pics do the talking.

After grinding both spots in cylinder's 1 and 4