Topic: Dirty Old K1

[G3]

Just starting a 750 K1 project.  I was looking for a winter project.  Thought about an MG but don't have the space.  Then I saw some 750 projects on line and I knew it would be perfect. 

Tracked down a 71 in Bismarck and went to take a look.  The bike was being sold by the original owner, who bought it in Rota, Spain when he was in the Navy.  When I heard that, I knew it was fate as I am an ex sailor also and we really clicked.

I'm pretty sure the thing had been sitting in the corner of his garage for at least ten years.  He had taken the engine out because he said it had been blowing oil out one of the exhaust pipes, so I got myself a rolling chassis, a motor and a few buckets of parts--best $500 I ever spent.

I had the frame stripped and parts arranged in storage bins in a couple of days.  After degreasing, it looked to be in pretty good shape.  The chrome on the wheels is near perfect and the frame is rust free.  The frame and trailing arm are out for sandblasting, a set of Dunlop 404s are on the way, and the carbs are out for a rebuild.  I have a top end gasket kit and rings on the way also. 

I've been to the local Honda dealer and the local Kawasaki dealer looking for someone to do the top end rebuild.  The Honda guys didn't seem too enthusiastic when I told them what I had, but they gave me an estimate which I thought was ludacris.  The Kawi guys were much more receptive and they had an old Triumph on the bench when I came in to talk so I think they are the right guys for me.  The Honda shop was a real disappointment.

So here it is...another one saved (the PO was going to part it out).  I'm looking forward to tapping into the collective knowledge here and seeing what I end up with.

[SOHC4 Cafe Racer Fan]

Local dealers are not the best choice for a vintage CB engine build. They will rape you with hourly shop rates and usually don't know what to look out for.

Your better off finding someone who has more experience building vintage Honda motors. You might be able to negotiate a better flat rate, too.

[MoMo]

Local dealers are not the best choice for a vintage CB engine build. They will rape you with hourly shop rates and usually don't know what to look out for.

Your better off finding someone who has more experience building vintage Honda motors. You might be able to negotiate a better flat rate, too.

Agree with that.  You'd be better off doing it yourself with a manual, Hondaman's book and help from this forum....Larry

[lwahples]

Looks like a good project.Most of the hard to find parts came with it.

[Dream750]

Welcome to the forums.

Good thing that you were able to save the bike before the PO parted it out. Looks like your K1 has the German market turn signals, tail light and tag bracket. Those are rarely seen in the USA and adds to the cool factor.

[G3]

Hey thanks.  Good to know.  I thought there must have been something a little different when the PO told me he bought it in Spain.  He gave me the original km/h speedo when I bought the bike.

[Dream750]

You’re welcome. This link has the different market model parts diagrams that you can browse:

http://www.cmsnl.com/honda-cb750-four_model14344/

Also, it would be helpful if you posted up your frame and engine serial numbers for a positive ID. With that information, the members here can better assist you with your project.

Bikes owned by US military members do tend to get around the world as they often can be shipped as household goods and not as a vehicle.

[BPellerine]

+1 on not going to dealers they can barely find a part no for these old bikes unless they have been around a very long time.bill

[G3]

Good idea Dream 750.

Frame - 1063843
Engine - 1064198

[G3]

The bikes below are very similar to what I had in mind when I started.  I like the 750 just a bit lower, with some bobbed fenders, but can't say I'm a fan of the club man handlebar.  I think a drag bar would be as much as my back could take.  A euro/superbike handlebar is the direction I'm heading now.  Ordered some trashed CB550 forks off that auction site and I'm looking at a shorty shock in the back.

[G3]

Don't know yet if I will do the top end rebuild or have it done (that's a picture of my deck, near my unheated garage), but I have received the gasket kit and rings.  Does anybody have any horror stories resulting from the use of Rik rings and an Athena gasket kit?

[Tews19]

Nice find and great project. Not sure if you plan to keep for a while or something to do as a flip. But if you bring back to K1 stock you will get the most in resale. K1's are my favorite as I have had a few and my daily rider in my Candy gold K1. The engine shouldn't be bad at all. This coming from a guy who was afraid to take a tank off my first 550 a few years ago. I have taken a few down to the frame, one 550 I am currently doing the engine on. Get HondaMan's book and dive in.. This site has the best members and will walk you through step by step if you need the assistance.

[G3]

Can anyone tell me how close the camshaft index mark needs to be aligned with the top of the head before I remove the rockers?  Its only a few degrees off and the key is up.  I can't rotate the engine anymore and I'm too antsy to wait a couple more days for the damn plug wrench!

[G3]

Here's a shot of the current position and remarkably clean valve train.

[G3]

Can anybody tell me if the later model (smaller) oil tank will fit on a 71 750?  They just seem to fit into the "V" of the frame better.

[G3]

Just a progress report here.

I received my plug wrench and got the crank in the right position for disassembly.  As it turns out, it was also in gear, which is a bit embarrassing.  The cylinder in question (the one on the right, facing forward...1? or 4?) did indeed show some evidence of ring problems.  It was the one that was the "most stuck" as I tried to pull the cylinder block and showed a small spot of what looks like garden variety rust on the cylinder wall where the piston has been stopped for the last 15 years.  Hopefully it will hone out.

I also discovered a twisted off exhaust flange bolt on the 2 (3?) cylinder that I'll  have to deal with.

[Stev-o]

Can anybody tell me if the later model (smaller) oil tank will fit on a 71 750? 

Not sure but have one to sell if you want it.

[G3]

I'd like to pass on some build experience here--two items to not waste your money on are Permatex gasket remover and Rustoleum aircraft stripper.  The Rustoleum was no surprise.  It was Sunday and all the parts stores were closed so I picked up some of this at Wally World.  It's definitely toxic but it didn't even begin to lift the clearcoat on my valve cover, even after leaving it on for far longer than recommended.  the Permatex, however,just seems like snake oil to me.  It did nothing on for either gasket removal or carbon removal as I had seen on many forums.  I think Permatex has a marketing department that does nothing all day but find build forums and posts things like "this stuff is great!"  Believe me it's not.

[MoMo]

#1 left ...Larry

[G3]

Sorry, Larry...I don't have all the lingo down yet.  What do you mean?

[MoMo]

Sorry, Larry...I don't have all the lingo down yet.  What do you mean?

It seemed to me that you weren't sure of the cylinder number sequence.  If you are ignore the post, if not the left cylinder is #1, then 2, 3 and 4 going to the right...Larry

[G3]

Got it.  Thanks.  I've looked in the manual several times to check the numbering but can never remember which side to start from.

[D-Ral]

Acetone is good for old gasket crap. Fingernail polish remover, too.

[Tsunami]

G3. Nice of you to join us, many years of experience here.  Couple of tips, use a digital camera and document everything, get lots of plastic bags for your parts, write it down you will forget something's.  Bag the fasteners with each part. Sometimes I go as far to document which screw came from which hole because of the lengths esp. on covers. Not a big thing but often times we buy aftermarket fasteners, stainless, chrome etc. and the particular screw for a particular hole is not market and they are not sized in the parts list.  Which brings up another thought.  When trying to match up parts, there are any number of sites that sell OEM parts and use OEM parts books to list them and have all the part #s.  that's an easy way to see if different years fit each other.  And remember that a biker with bugs on his teeth is a happy biker!  Everyone sooner or later gets wacked in the teeth by a wayward bug, if not then their not having any fun or they would be smiling. Never do the ton on Sunday too many people in the emergency rooms. Keep the oily side down and never look back because it makes you think you might pull over for the car with funny red and blue lights. Humor is never in short supply here. So when your just about to kick the ol two wheeled girl, stop and come to this site and read others woes, IT WILL MAKE YOU FEEL BETTER AND MIGHT FIND A SOLUTION TO YOUR PROBLEM!  Happy Days

[G3]

Build update:

The frame and swingarm are back from the powder coater.  There are a few thin spots but overall it looks pretty good.  I paid $200 to have the frame and swingarm sandblasted and powder coated.  A body shop wanted $500 to blast and paint so I think I made the right decision.  Lessons learned:  Remove everything you don't want powdercoated before taking it to the shop--bushings and stray fasteners get coated just as easily as the frame itself.

Re-assembly has begun.  I sanded and painted the leftover items such as battery box, tool roll niche, motor mount plates, foot pegs and triple trees with Krylon Industrial Rust Tough enamel and baked them in the oven for about an hour at 180.  It sure makes the curing time more tolerable and seems to result in a pretty good finish.  Time will tell how durable it really is.  If I had it to do over, I would have taken the time to deliver all these smaller items with the frame and swingarm for powder.  It would have been much more convenient and ultimately durable.  lack of patience gets me again... 

I installed tapered steering bearings.  The process wasn't too bad.  I did have to take the lower tree to a machine shop to have the old bearing removed from the shaft, but it only took a few minutes.

I also installed needle bearings in the swingarm.  The old bushings were a bear to get out but I persisted.  I used the "hacksaw cut slot" method that has been discussed elsewhere in this forum.  Know that there is a small shoulder behind the bushing, so don't try to press it out tot he other side.  It also prevents you from being able to cut all the way through the bushing with the hacksaw but you can still get it out with a partial slot.

I've looked over the old wiring harness and decided to use it.  There are a couple of bad connectors but nothing I can't repair.