This took more than 5 minutes.
WD-40 is excellent for cleaning carbs.
Not wery cheap but I think worth every cent
The old one hasn't been accelerating anything for the last 20 years, it was so stuck I had to use a small hammer to get it out. Also known as diaphragm or membrane pump. This is one of those many things that separate K7 from earlier models, they dont have it. I do.
Nobody wanted to buy this old seat at a swap meet and it pissed me off so much that I restored it completely and sold the new plastic replica seat at a swap meet. Rusty from top..
...to bottom
I mean very rusty
Never seen rusted leather before
Removing rust with electricity, very effective, called electrolysis
Also the paint took off, which was nice.
Rust is gone but now there is a black coating that has to be removed before powdercoating
Not bad, it starts to look like a seatpan
Nothing is more important than well organized working area
Seat also needed some refurbishing, I used canvas.
Pan was broken from both sides, too thin to use MIG-welding so I used spotwelding. Here You can see how the rust is removed from those badly corroted places by electrolysis
Support piece in place with locking pliers
Never done spotwelding before and if I can do it anyone can.
Waiting to be powdercoated
Well this wouldn't rust anymore
I had to use glue to attach the new seatcover, the old fasteners were too worn out.
It was much harder to find the chrometape than to attach it
That's it and I hope I never ever have to do that again.
Camchain and tensioners were worn out
and as You can see CMSNL-image
and as You can see CMSNL-image
and as You can see CMSNL-image
and as You can see CMSNL-image
This tip is from SatanicMechanic, according to them the primary chains should be offset by one tooth
This is what it should look like, the original image of Honda CB750 K7 1977....
..and this is what it really looked like, yes I know it looked rather nice from distance...there are still these moments when I wish I'd kept my distance..
..and this is what it looks like now after 13 months.
First paint then stripes which are like big stickers (and by the way wrong colour for this bike, thank You germans, that orange stripe should be red) and finally lacquer paint, yes I know should have bought new emblems also but 70 € a piece, I think these do just fine, at least for a while.
Lot of cleaning, perhaps sodablasting and of course painting and that's only the outside...
a rolling chassis
After sodablasting and washing it looks much better
After sodablasting and washing it looks much better
Standard pistons are in good condition and after thorough cleaning look like new.
Example of oversize piston
After sodablasting
Cylinder before sodablasting...
..and after.
After sodablasting
After painting...
After painting...
After painting...
After painting...
After painting...
After Tig welding...
When assembling the lifterplate, put two longer bolts to opposite holes and pull the clutch together, hold it there and put the original bolts to those empty holes and gently put some pressure to the springs , done this replace long bolts with normal bolts and start tightening 1/4 turn/bolt.
New exhaust and mufflers, ordered from CMSNL, had to say that because I use their image, new bolts, pillions with brackets and of course these are totally different than those on K0-K6
This kit is a very good choice
After assembly the clutch was sort of slack and we found out that one plate was missing, that nr.6 called plate B doesn't include to the clutch kit, so we used the old one.
Slowly rotate the crankshaft untill the intake valve of cylinder nr. 1 first goes down and then comes up, keep rotating until "1-4 T"-mark is in place, now You can adjust the "yellow" valves, after that You rotate the crankshaft 360 degrees until that "1-4 T" -mark is in place again, now You can adjust the blue valves. Simple
   
 
Suomeksiin english
   

Honda CB 750 K7


CB750 K7 (June 1976-May 1977) Frame from CB750K-2700 002 Engine from CB750E-2700 001 Numbers built: CB750 K7 38.000


 


Engine
The engine and the vicious circle begins.....
It says in the manual that lift the engine off from the right side of the frame, Yes, it took like half an hour and three men to some how get it out and I already see nightmares about putting it back. I got a good tip, attach the oilpan after the engine is in place, You get almost an extra inch of free space, should be a lot easier. There is not a single bolt that hasn't been raped by the previous owner, did I get something in my eye ?
..no it is just one of the 16 cylinderhead cover bolts after previous owners tightening, took me half a day and almost every tool i have to get the cylinderhead cover off.
All bolts had to be replaced, we managed to break three bolts and it was almost half a days job to take them out.
The engine ran guite well, headgasket had a small leak on the left side so it had to be changed, I ordered the complete gasket set
Quite a lot of stuff for 49 € for example those 4 copper rings at lower right corner are for the exhaustpipes and when I took the pipes off there were no gaskets at all.
, it comes much cheaper that way and the quality is very good. CB750 engines tends to have this rattling sound when they are on idle but this one was a little bit too noisy, meaning that primary chain/ tensioner or camchain/ tensioner had to be changed or both, of course both. One of those jobs that I'm looking over someones sholder while he is doing it. CMSNL site is the only site I found very important info about the framenumbers for example there are two different sets of valveguides
Right exhaust and intake valveguides for my K7.
to K7 depending on the frame number, in this case upto serial: 2719 529 and from serial: 2719 530 and so on. My bike is CB750K-2723 669. You can identify Your bike at HondaChoppers exellent site. I took the cylinderhead and valves, quides and rubbers to a engine repair shop and the owner told me that only the exhaust valvequides should be replaced and after two weeks it was ready.
They told me at the repairshop that these tiny holes are the main reason if something goes wrong after assembly. Through these holes camshaft and holder get its lubrication and it needs only a drop of gasket seal to block them.
Here it starts that vicious circle: If You are changing the headgasket You have to take camshaft and cylinderhead off and when they are off why not change the valves, valveguides and rubbers as well and the camchain/ tensioners, rubbers etc.
Dismantling the engine was quite simple except those few crankcase bolts and this holder
Those four bolts were so tight that they had to be drilled out.
at end of the counter shaft. When we got it open I was suprised how simple it really is
simple
.
Pistons and cylinders are in good condition and after measuring we found out that they are standard pistons and within acceptable limits both pistons and rings. After sodablasting and washing the crankcase we changed all oilseals, one transmission ballbearing, then just put the upper crankcase part face down on the floor and everything back in place, then the lower part and that's it, I renewed all the bolts and screws. Also the oilpump was in good condition except the oil leak valve that keeps the oiltank full was renewed.
I found a good and simple instructions to adjust the valves.
There was something wrong with the clutch also, when You put the first gear on , instead of that nice Japanese "click" You got that Harley Davidson "clank", adjusting the clutchcable only made it worse, so obviesly the clutchplates and springs
needed to be changed also. After dismounting the clutch we found a piece missing from the platelifter
The piece must have been there quite a while.
, it just lay under the clutch assembly and when we measured the plates they were allmost like new but the gaps in cluthc disks
were full of black "stuff" so we figured that it has been slipping quite some time. The new platelifter arrived and we tried to install it but of course we broke it, just like the old one, luckily I know someone who knows how to weld aluminium, so after some welding and filing the clutch was ready.
I took the engine parts, crankcase, cylinder, cylinderhead and headcover to be sodablasted, never used soda before but after blasting I can only recommend
Soodablasted and polished valvecover
, parts are like new. So the engine must be painted and Honda engine color is "Cloud Silver Metallic", NH-35M , PPG Paint Code 33778, but I found out that the best paint for this job is VHT Engine Enamel
VHT Engine Enamel SP127 Universal Aluminum
, SP127 Universal Aluminum, looks exactly like original and it is heat resistant to 550°F (288°C) and very easy to paint. I renewed also all engine bolts and screws, that sounds easy but there are "few" bolts.The oil drain bolt and threads were destroyed completely, the bolt was so loose that it can be removed by hand, so new bigger hole, new threads and new bolt, the bolt was not magnetic so I placed a strong magnet on the bolt, works fine.
Finally the engine was ready to be attached to the frame, I covered the frame with plastic tube
Easy and cheap
, removed the exhaust pipe studs and after a "little" wrestling, the engine was in place. Of course we had to start it and it started nicely, a "little bit" loud without silencers. After that the exhaust pipes were mounted, the boxes were labelled a-b-c-d and we thought they ment 1-2-3-4, nope, nr. 1 and nr. 2 went well but nr. 3 didn't, it was actually nr. 4 (?). There were also small markings on each pipe: i-L/i-R and SL/SR= inner left/right and Side left/right which we found out later of course.
The final drive rear sprocket was the only thing in this bike that I thaught was OK, it looked like new (?) but when we ordered the front sprocket and new O-ring chain (88 links), after assembly the chain was too slack, we noticed that the rear sprocket was too small, only 36 teeth and it should be 41, well I had only one year to count those teeth, but...