Topic: Some buying advice for a CB750 please!

[caemca]

Hi guys!
I just registered, so this is my first post! 
I live in Europe and I'm looking for a nice CB750K to buy... This has to be the right place to get some questions answered! 

There is not much right now on the market, but I could find three candidates nevertheless.

Two K2 in gold and a K6 in blue. 
I didn't have yet the time to go and have a proper look at them, but I have some nice pictures.

The first K2 (from April 1972) has 18000 miles on the clock.
It has a dual disc front brake.
From the pictures I can make out some bent fins on head and cylinders.
On the left side of the head, the fins look brittle and lost small chunks. This can't be normal!

The other K2 (1973) has covered about 33000 miles.
It looks very nice (apart from the red spark plugs' caps... )

The K6 (April 1977) has done 26000 miles.
From the pictures it looks very clean and nice.

The last two are in about the same price range, the first K2 I mentioned (18000miles with bent fins) being priced a bit higher.

Aesthetically I prefer the earlier K2s... The gold color, the small decals on the tank and the simpler "750 Four" side cover emblems.
I understand the K6 should be quite down on power, compared to earlier versions.

What would you recommend?

I can post some pictures, if it helps...
Thanks guys!!
Carlo

[b52bombardier1]

Are the bikes complete, especially the small cosmetic pieces?  Those things are hard to find.

Do they run?  Any smoke at the tail pipe idling or accelerating?  Do they start easily?  Does the clutch slip?  Tires in good shape?

Put a multimeter on the battery with the engine running and measure the AC and DC voltages at maybe 3000 rpm.  This will tell you the health of the recharging and voltage regulating systems.

  If you enjoy a little work with a wrench, all of the things above will be easily solvable. Run a perpetual EBay "Followed Search" for anything missing and the items will eventually show up. Buy the most complete bike that matches your mechanical abilities / likes and you will be happier.  And I would not worry too much about the horsepower differences through the different model years.

  All of these bikes are plenty fast enough to kill you.  Even my 90 CC bikes below are just barely fast enough to kill me . . . 

Rick

[caemca]

Hi B52! Thanks for your answer! 

All of these three bikes are complete. Well, I guess the K6 is missing the front disc splash guard. But that's pretty much it. 

All bikes run, I'm not willing to rebuild an engine just yet... I'll soon find out if they smoke or run dirty.

I'm not worried about having too few horses, but I'd like to have the best running engine possible (I'd love the bike to be as reliable as it gets!)

I'm scared by the brittle/bent fins on the first K2, but I like it having less miles than the others and the double disc brake.
How many miles... are too many?  What about the fins?
I know, these are stupid questions... But I got to start somewhere!

[PeWe]

Complete with fresh OEM 4-4 exhaust?
Brittle fins on cyl and head look like mechanical mistake, abuse?
 or the metal has disappeared like contact with chemicals (caustic soda) or salty environment?
HP can be corrected

A fresh CB750 in full original shape is something very nice!
My CB750 K6 look close to original with 4-4, fresh paint. I get very nice comments from people everytime I take a ride on it and have a stop.

If price is right you might need them all!

[caemca]

Yes, the right exhausts are there 

I don't think the bike was in a salty environment, at least not for long enough to cause such trouble!
I hope the pictures help, I know those are not the best angles but you can see the bent and the broken fins.
What do you think?  :

[harisuluv]

I don't think anyone is going to provide you with an educated answer without pictures of each bike and the asking price.

[Johnie]

Not sure what the deal is in Europe, but in the states we like to get bikes that have a title. We can jump through some hoops in the USA to get a title, but having one up front is a plus. That exhaust might look good from the side, but the bottom is what you need to see or at least ask the owner about. That is where the holes will appear. A good OEM exhaust will cost you over $1500+ now that Honda no longer makes them. However, you can find them around. Even a decent set of used ones show up every so often, but are costly.

[Stev-o]

+1...someone has been into that motor and either had trouble taking it apart or didn't know what they were doing.

Go look, touch, ride each bike, see if any particular one speaks to you. 

Do you have pics of the entire bike?

[caemca]

Thank you all a lot for your help! This community is awesome!

Titles are clean on all three bikes!

I have some pictures of the bikes, I'll upload some now.
The bike in this post is the K2 with the lower mileage and the broken fins.

[caemca]

I'm trying to post more pictures, but I keep getting some problem...

I'll try this other way, uploading them outside of this page!

This is the second K2, with higher mileage and red spark plug caps.

[caemca]

This is the K6... As you can see, very very clean.

[caemca]

Yes, the right exhausts are there 

I don't think the bike was in a salty environment, at least not for long enough to cause such trouble!
I hope the pictures help, I know those are not the best angles but you can see the bent and the broken fins.
What do you think?  :

This bike has been modified. The valve cover polished, the screws replaced with socket caps, etc. The chips and bent fins are likely down to the cylinders themselves being removed, which could mean some minor engine work was done. I would inquire specifically about any work done, receipts for it, and when it was done.

This is not to discourage you from pursuing this bike, only identifying some non-stock aspects of it for you.

Thanks for your opinion!
I will ask the owner about the work done, but I have to admit it puts me off nevertheless!
Any engine work with 18000 miles on the clock would make me at least quite suspicious...

[caemca]

Hi calj737!

I understand the first K2 has had some work done... And the brakes mod!
That's not properly original anymore, yes. I'll contact the owner later, and ask him about it.

What about the second K2? Apart from the red spark plug cables, I mean 
I really like it, but the mileage (33000!) on it sounds pretty high to me!

About that K6... Well, it looks like new, doesn't it?
Unfortunately the mileage is not low (26000) and somehow I think the previous iterations have more of that "vintage feel" to them...

What about reliability?
Did Honda really improve the bike through the years or was it just making it softer and environment-friendlier?

[caemca]

You are surely right, it's definitely better for a motorcycle to be ridden regularly... But you never know, it could have done 20000 miles in 2 years and sat for the last 35. 

About the vintages (it sounds like we are talking about some old red wines ), I got the impression the K0 to K2 are more interesting from a collector's point of view, and they therefore usually command higher market prices. Is it still true?

I just had a chat with the owner of the K2 with the broken fins...
He doesn't know anything about the bike! 
He bought it from a dealer (specialised in "keeping vintage japanese bikes on the road") in May this year as a less troublesome alternative to his 850 Norton.
He rode it about 150 miles this summer and realised he hasn't got time to ride.
He gave me the name of the dealership, I will contact them directly and ask what they did on this bike.

The owner of the K6 was more useful 
He told me he bought the bike 5-6 years ago.
Back then he had it serviced at a Honda dealership, replaced the whole exhaust, the rear tire, the handlebar (it had a weird one on), both side-panels and had the carbs cleaned, overhauled and sync'd.
Since then he rode about 1500 miles on it, always checked the fluid levels but never properly changed the oils.

Couldn't reach the owner of the second K2, he will hopefully call me back later.

I'm starting to think the low-mileage one was rebuilt by the dealer... Not that low-mileage after all!  :

[Johnie]

That 2nd K2 bike has some awfully long throttle cables on it. Wonder if it had taller bars on at one time. As far as the engine work, these bikes had an oil weep around the head gasket which was real common. Possibly that was repaired in the bike that had the work. If so, you are one up on that issue. Last...ask to see the title and compare the VIN number on the bike with the title before you exchange the cash.

[Johnie]

The 1969 sandcast is in a league of its own. The KO - K1 are the most collectable with the K2 right behind. But the K3 - K6 are coming up fast as the years tick by. My thoughts are all those bikes look pretty nice. Not to often you can have 3 bikes to choose from. Best if you can take them for a ride...or at least have the owner drive it if he won't let you drive it until you exchange the cash. Follow him in a car so you can hear it run and see if it smokes. What kind of cash are they asking for the 3 in USA dollars?

[caemca]

Oh man, I didn't even notice those  EXTREMELY long throttle cables! 
I have to better study those pictures.
I didn't know about this oil weeping problem...
It would be nice to have a bike with it already sorted out, but with the broken and bent fins this one really looks like an amateur job!
I'll contact the dealership as soon as I can and get some answers... I hope.

I already made appointments for next monday and tuesday to have a look at the two bikes.

I read a lot about sandcasts, but I'm not interested in one since I'd like to ride the bike and not just look at it dripping oil on the garage floor
The K2 is actually my favourite model, if just talking aesthetics.
I'm growing to like the K6 as well, but as I already mentioned, it looks less... classy... to me!

These three cost around 7000-8000 USD, I'd like to get an interesting model for that kind of money!
Unfortunately big bikes were never as successful here as they were in the US, so they are not easy to find and command very high prices.

What about replacement parts? Does Honda still make something for these bikes?

[Johnie]

Yes, Honda does still have parts for these bikes so before you pay high eBay prices check with your dealer. Better yet, post what you need on this forum in the "wanted" section. They guys here sell and trade parts all the time. We really help each other out. $7,000 - $8,000 is a bit high in USA prices. I do admit I like the K6 there, but if you want that early vintage look then go with the K2. And by all means check the bottom of those exhaust pipes. As icing on the cake find out if the bike comes with the owners manual and tool kit which would be under the seat.

[754]

Check thebuild. Date on the neck of the K6, it may be a75..the signals have been changed for  the better, and taillight maybe. The front signals should mount further back in the hole that is there, if you drop it, may save the headlight shell..

[Stev-o]

Where in Europe are you?

[caemca]

I do like the K6 as well, Johnie... From the pictures it really looks as clean as new (some oxidation spots on the front forks, maybe...)
The seller of the K6 said he has the original owner's manual and the tool box, the K2 guy didn't really know.
So I'll assume he doesn't have them.

I'm located in Switzerland, we always had different laws about turn signals and lights... Can't really say what's original and what is not!
I'm looking on the swiss, italian and german market right now.
 
The K6 was actually first registered in April 1977, I doubt it's a '75... But I'll check nevertheless! What do you think does not match?

[PeWe]

The K6 look really good. My bike looked exactly like that when I bought it early 1979.
It has the mud flap too which I have not found as sparepart anywhere.
- One thing though, front blinkers are mounted in wrong holes in the ears. It should be bolts holding the lamp bucket in front holes, blinkers mounted in the empty holes.

K6 tank is better when you get lack of fuel and time to twist to reserve doing it with left hand while the right can keep the bike running by increasing the throttle. Only one fuel hose too.

I have mine but with a hole thru the Honda logo since we had to add an extra reflex to pass the vehicle inspection that did not like the rear lamp. All here in Sweden has that hole.

One detail to look for is the exhaust systems. Check if the older bikes have got them replaced back in the days. If you are lucky you will find fresh K0 exhausts marked HM300 instead of HM341 as all of them should have. Or maybe an earlier before HM300 markings....
A good original HM300 are worth much more. The pipes have better flow too. Sandcast restoring guys like correct pipes too.

Chromed valve cover is as I see it not good since the chrome can flake and look horrible. Find another one while still available for not much.

All of them look good. I have seen similar bikes here (this year) in Sweden where they ask 4.500-7.500 Euro.

Edit: Check for cracked side covers (at the middle of it from front). Very easy to crack them when leaning the bike on one side pressing against leg when standing still. Easy to crack them when removing them too, around the any of the 3 pegs holding them.

[caemca]

I called the dealership of the first "low mileage" K2.
They told me they serviced it, replaced the exhaust with an original 341, the body set is new (just as you thought, calj737!), the swingarm was the wrong one (?) and got exchanged. They also told me their receipt says the bike had 45000 miles as they sold it. Mmmh. 
The guy at the dealership and I got talking and he advised me not to spend too much money on a K6 because, I'm quoting him, "nobody wants one".

I got ahold of the owner of the other K2, the one with the very long throttle cables.
He was at work, not too much time to talk...
He said there are already two potential buyers who will have a look at the bike later this week.
I can't really make it to him before the other guys, so I guess that's a loss.

PeWe, I don't know what happened with the blinkers...
I'm pretty sure none of these bikes will have a HM300 on...
The side covers on the K6 are new.

[harisuluv]

Nobody wants a K6?  I think he is thinking of K7 and beyond.  K6 was the last year of the desirable SOHCs.

If that is the caliber of bike you're looking for, why not buy it off ebay if you can't find one?  Is that an option where you live?

[Stev-o]

Nobody wants a K6?  I think he is thinking of K7 and beyond.  K6 was the last year of the desirable SOHCs.

+1.  Do you know if the K6 was originally blue?  Planet Blue was a K5 color only (at least in America) but who knows what has been done to a forty year old bike?!