Topic: The 750K8 Cape Ann Teardown

[Curran]

Got a film degree... YouTube came out.  Became a plumber... basements aren't thrilling.  Half started a 78' bmw 2002.  Fixed up a broken Civic to daily drive to work.

Bought a 500 dollar CB750K8.  Never ridden a motorcycle outside of a theme park.

Researching and learning from scratch.  Exploding the bike apart to find out what makes the world work.  I'm out North o Boston and ready to rip.  Been cruising the forums for info for awhile now and really just starting to find out that k7 k8 adds a layer of confusion to parts.

Wish me luck I'll be a self certified k8 mechanic by the end... or at least have a k8 coffee table.

Bear with me on the foruming, never forumed before.

[Curran]

Finished Theory-fying the crap out of it and seeing that it didn't change anything yet.

Stripped the beast down.  Got all the parts separated and organized.  Shook the frame off the engine and have the bike to the point it looks like someone left dynamite near it.

Currently on a buy spree to prep for the haul.  Pictures to come in a bit.  Carbon build up is bad.  Going to do engine rebuild.  Been reading lots of stories bout it.  Since mine is a k8 i've just been gettin pissed that every part stops at 76 and someone changed it up and stopped sellin mine.

I've got ordered so far:
Piston rings - servicehonda
complete gasket set - cyclex

Where can I get a heavy duty cam chain since Z1 enterprises is out of stock?
Is the New SFK Oil Seal Set Honda CB750 K & F bikes 1969-1976 from rusty riders a fit for my K8?
Who is Terry Quail or where do I get oem primary chains?

I'm not going for increased performance.  Well increased from a spewing beaten engine to a smooth happy one.  What am I missing what do I need what should I scoop up and where?

Pictures rollin out when the girl, "camera operator", rolls back.

[becuzlc]

hey there. In the same boat as you as far as knowledge is concerned and motorcycle experience. Started breaking down a 77k myself so I will be paying attention. Good luck to you.

here's a few links that I found helpful so far, the google custom search is pretty nice:

http://forums.sohc4.net/index.php?topic=88853.0
http://forums.sohc4.net/index.php?topic=29364.0

Sorry can't be more help others may chime in.

[Curran]

Ive read the full rebuild for dummies, dyrden's, hednut's and a bunch of others.

Found a sandblasting monument company.  Should i sand bead soda blast anything or use a2 paint stripper and wire brush sandpaper?

Is there a homebrew remedy to obliterate chrome from existence?
Things to be stripped/painted:
Frame swingarm forks
tank
rims
exhaust
side covers
Engine
carbs

[Cheffish]

Stripper works fine but is a little time consuming. It's cheap though. Sandblasting is way faster but will cost some loot to have somebody do it.

[Curran]

I read someone used 'JASCO' paint remover and some sanding out the little bits.

After a million paint scheme ideas.  I want to clear coat raw metal, wrap the exhausts to give it some vintage / military style and make a rich leather couch style seat.  Can't decide on the half rusty chrome bits.  Withotu dechroming or rechroming it's stuck in the awful inbetween.  How is powersanding that down to a messy metal for clearcoat on this gonna go?

Canvas - Leather - Iron
That should do it.  Will the methods work?

[Cheffish]

Buy some aircraft paint remover from home depot. Spray down the tank. Wait like 10-15 minutes. Then hose it off. Repeat. I bet all the paint will be gone after the second coat of stripper.

[knowsnothing]

Just a word of caution - I know of a people who have been very unhappy with the results of clear coating raw metal.  The clear coat has a tendency to crack and yellow in the sun.  If you want to keep the tank raw metal, the best thing I have heard is just to put a coat of wax on it and every to often buff it up again.

Good luck

[Curran]

whats a clearcoat that might not yellow?

[Cheffish]

whats a clearcoat that might not yellow?

I'm not sure. But it also will have trouble sticking to the metal if you want the tank polished. My buddy's sportster tank was raw steel for years without issue. He used to oil it every so often to keep it from rusting.

[Curran]

Looking into cerakote gun coating for the flexible hard adhere to metal application.

[Curran]

Beautiful day outside the new setup at the motorcycle/surf/snow/dirt/beer n' pizza/ dive garage.
Top End rebuild has begun!

The outside is dirty.  The inside is dirty.  The carbon build up is pretty heavy.  The intake and exhaust have been stuffed full of oreos.  #4 looks lean and #3 looks rich.  #2 cylinder is rough.  Pictures - !

Someone has always told me something about the "right tool for the job"

Trying to be organized.

If you see anything rough that should get replaced or a way to clean it or where to buy it.  Let me know.  It's been hell trying to figure out all the random parts that make up the damn K8 model.


I've read all over this place and only have a faint idea of how to lap valves.  Any ideas where to get the cheapest workable valve compressor tool?

[Curran]

Peanut Butter and Jelly has never looked so good after 30 years.



Hanger to the rescue!

Apparently my k8 runs on charcoal compression with no ratio for diamond exhaust.

Gotta grab a honing bit for the drill and see what can be salvaged.  Don't want to do an overbore.

Decently clean now on the inside.  The outside is another matter.

New 630 x 88 o ring chain off ebay
CycleX gasket set for top end
Stainless bolts for all the phillips heads I gummed up.
Piston rings not shown but I got those.
Can't figure out what kind of pistons this k8 has.  I got a pic with the side of one if anyone knows.
Airbox from the Great White North forum canada man!  Thanks! The greenbacks are in the mail, sorry for delay, been moving my girlfriend's parents back into their house.  Construction on it is done after a year cuz a fire thrashed the house to the ground!

Life back on track here.  Manual printed out and bound 270 pages of happy!

[Curran]

Mystery to me piston.

C 392      6?

[Curran]

Looking ugly but the case does not have a hole in it!  Thanks PO for not slashing a chain through it.
Went to Dunkin Donuts out in Beverly and right out front I found this little beauty

almost ran off to go get my Frame and make the switch, see if he notices.  Who's is this and what are they doing not having a beer down at the shop 1 street away?

[madmtnmotors]

Is the New SFK Oil Seal Set Honda CB750 K & F bikes 1969-1976 from rusty riders a fit for my K8?

The oil seals are the same with the exception of the primary output shaft (behind the front sprocket). This seal is often sold seprately, and some kits even include both.

DON'T use aircraft paint stripper (and many other paint strippers for that matter) on the plastic side covers, IT CAN MELT THE PLASTIC! 

Good luck, I've enjoyed my 750 K8 for twenty-six years. 

[Curran]

I wouldnt dare subject plastic to that stripper.  I got some of the flaking paint on my arm and it was trying to burn through to my core!  Thanks for the tip on oil seals!