1975 CB750 K5

"Matt" <themattfella.RemoveThis@xxyyyzzzz.com> wrote in message
news:QGT2f.9541$cg.7441@news02.roc.ny...
> Thinking of moving to a '75 Honda 750 with 13K miles and would like to
> know what good and bad points to look for with this model.


Hold on there Matt, you're really climbing the scale on
the "state of the art" meter. <g>

So, let's see, depending on the bike's anniversary, it's
around 30 years old. At 13K miles, that looks like about
430+ miles a year. No sense in burin' up the road, I guess.

However, I suspect that rather than a linear 430 MPY, the bike was used more
consistently in its early years,
and then parked/abandoned(I'm only guessing) later.

If it's had long periods of inactivity, I would be looking
at bad tires, possible battery leakage/damage, and the
presence of rust.

I can't recall the K5, but I had a '73 K3. It was a four
pipe model, and they were notorious for muffler rusting.
Even back then.

I would also be looking at the fuel purity coming out of
the tank, as well as the same respect to the oil. Of course,
these items could have just been cleaned/changed. Might
want to drain a float bowl or two and check the gas there.

Carefully check all rubber condition(front fork covers, if
they exist, air intake tunnels, etc.). Put the bike on the
centerstand, fire it up, put it in some gear, and let spin the
rear wheel. Check the wheel for true. Run up the engine
and check for exhaust smoking. Listen to the chain for
and excessive noise or binding sounds. Listen to the engine for unusual
noises. My K3 was a single OHC.
Don't know when the DOHC models came about. It
might have a noisy camchain. Obviously, look for any
oil leaks, and if it's liquid cooled, and coolant leaks.

The check list is endless....


Gary
 >> Stay informed about: 1975 CB750 K5 

Gary Walker wrote:

<snip>

> Don't know when the DOHC models came about. It
> might have a noisy camchain. Obviously, look for any
> oil leaks, and if it's liquid cooled, and coolant leaks.
>

Errmmmmm, if you aren't sure whether a K5 is air or liquid cooled, SOHC
or DOHC, it might be better not to offer advice at all.....

I ought to add - parts availability for the engines is till good. Even
the OE 4/4 exhausts are available. Trim and cosmetic parts, like side
panels and so forth, can be nightmares to source. It all depends on how
original it is, and how original one wants it to be, I suppose.

You're right about the four cans rusting, mind. They all did that.
Squirting a load of oil down the silencers helped.

That reminds me: recently I bought an utterly immaculate Honda CB125S,
all original, clean as you will ever find, 1972 vintage. The OE exhaust
was still in superb condition (it had been dry stored in a heated
building). I discovered that these exhausts are now utterly
unobtainable, and that not even pattern ones have the right style of
silencer.

So I recently bought a pattern system for a pushrod CG125 (which bolts
straight on) and replaced the OE system wit this. The OE exhaust has
had a pint of oil poured into it, and swilled around, and the faultless
chrome has been coated in grease. It's sealed in a plastic bag, hanging
in my garage, and when/if I sell the bike, it'll go back on.
 >> Stay informed about: 1975 CB750 K5 

Gary Walker wrote:
> <chateau.murray DeleteThis @btinternet.com> wrote in message
> news:1129119236.504667.300080@g43g2000cwa.googlegroups.com...
> > Gary Walker wrote:
> >
> > <snip>
> >
> > > Don't know when the DOHC models came about. It
> > > might have a noisy camchain. Obviously, look for any
> > > oil leaks, and if it's liquid cooled, and coolant leaks.
> > >
> >
> > Errmmmmm, if you aren't sure whether a K5 is air or liquid cooled, SOHC
> > or DOHC, it might be better not to offer advice at all.....
> >
>
>
> Well, not recalling a bike's manufacture history event is a
> lot different from not knowing of the that history. Did you see any text in
> my suggestion(s) that would make you believe I don't know what I'm talking
> about?
>
>
Oh, the general advice applicable to old bikes is great - agree
totally. But the answer to your question is, when it comes to this
specific model, "Yes".
 >> Stay informed about: 1975 CB750 K5 

Gary Walker wrote:

> I can't recall the K5, but I had a '73 K3. It was a four
> pipe model, and they were notorious for muffler rusting.
> Even back then.

I can recall the K5, my buddy had about a 1971 K1, and that was
totalled in a crash with a taxi cab, so he made the insurance company
buy him the K5 or he would sue them for the injuries sustained in the
accident.

Hey, a CB750 could be bought for as little as $1750 in those days of
the Carter Recession. Such a deal! Everybody bought 'em, even people
who didn't know how to ride...

But this kid I knew was a real operator. He had an XS650 and he let a
guy ride it and the guy hit a brick wall, so he demanded enough money
to get the K1, which was wrecked in the taxi cab accident. Then he had
the K5 for a few months and it was mysteriously stolen and he wound up
with a Volkwagen. Yamaha to VW in less than a year. Hmmmm....

> Don't know when the DOHC models came about.

CB750F was in 1979. There may have been 1978 DOHC's, check
www.partsfish.com
 >> Stay informed about: 1975 CB750 K5 

<chateau.murray RemoveThis @btinternet.com> wrote in message
news:1129119236.504667.300080@g43g2000cwa.googlegroups.com...
> Gary Walker wrote:
>
> <snip>
>
> > Don't know when the DOHC models came about. It
> > might have a noisy camchain. Obviously, look for any
> > oil leaks, and if it's liquid cooled, and coolant leaks.
> >
>
> Errmmmmm, if you aren't sure whether a K5 is air or liquid cooled, SOHC
> or DOHC, it might be better not to offer advice at all.....
>




Well, not recalling a bike's manufacture history event is a
lot different from not knowing of the that history. Did you see any text in
my suggestion(s) that would make you believe I don't know what I'm talking
about?




> I ought to add - parts availability for the engines is till good. Even
> the OE 4/4 exhausts are available. Trim and cosmetic parts, like side
> panels and so forth, can be nightmares to source. It all depends on how
> original it is, and how original one wants it to be, I suppose.
>
> You're right about the four cans rusting, mind. They all did that.
> Squirting a load of oil down the silencers helped.
>
> That reminds me: recently I bought an utterly immaculate Honda CB125S,
> all original, clean as you will ever find, 1972 vintage. The OE exhaust
> was still in superb condition (it had been dry stored in a heated
> building). I discovered that these exhausts are now utterly
> unobtainable, and that not even pattern ones have the right style of
> silencer.
>
> So I recently bought a pattern system for a pushrod CG125 (which bolts
> straight on) and replaced the OE system wit this. The OE exhaust has
> had a pint of oil poured into it, and swilled around, and the faultless
> chrome has been coated in grease. It's sealed in a plastic bag, hanging
> in my garage, and when/if I sell the bike, it'll go back on.
>
 >> Stay informed about: 1975 CB750 K5 

krusty kritter <kriyamanna.RemoveThis@aol.com> wrote:

> An original CB750 K Zero would be just too fragile for daily service,
> as many riders learned when the chain broke and took out the engine
> cases.

Actually, that was a problem that dogged *all* CB750s until the F2 and
K7 came along with beefed-up O-ring chains.

Damn nearly happened to me - it popped the spring link on the weedy
chain, lost the sideplate, and the two halves of the link wre just
opening out when I decided to stop for fuel and give the chain a lube at
the same time =:O


--
Trophy 1200 750SS TR65 GPz550 CB400F CB125S DT50MX
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....
 >> Stay informed about: 1975 CB750 K5 

Matt wrote:
> The Older Gentleman wrote:
> > krusty kritter <kriyamanna RemoveThis @aol.com> wrote:
> >
> >
> >>An original CB750 K Zero would be just too fragile for daily service,
> >>as many riders learned when the chain broke and took out the engine
> >>cases.
> >
> >
> > Actually, that was a problem that dogged *all* CB750s until the F2 and
> > K7 came along with beefed-up O-ring chains.
> >
> > Damn nearly happened to me - it popped the spring link on the weedy
> > chain, lost the sideplate, and the two halves of the link wre just
> > opening out when I decided to stop for fuel and give the chain a lube at
> > the same time =:O
>
> What are the details and mechanism of crankcase damage when the chain
> breaks?

The chain breaks a hole in the crankcases around the countershaft
sprocket.
The sand cast cases certainly can't be heliarc welded, and the die cast
cases probably can't be repaired either.

By comparison, Kawasaki's 900cc Z-1 and the KZ-1000 are built like
brick houses...
 >> Stay informed about: 1975 CB750 K5 

The Older Gentleman wrote:
> krusty kritter <kriyamanna.RemoveThis@aol.com> wrote:
>
>
>>An original CB750 K Zero would be just too fragile for daily service,
>>as many riders learned when the chain broke and took out the engine
>>cases.
>
>
> Actually, that was a problem that dogged *all* CB750s until the F2 and
> K7 came along with beefed-up O-ring chains.
>
> Damn nearly happened to me - it popped the spring link on the weedy
> chain, lost the sideplate, and the two halves of the link wre just
> opening out when I decided to stop for fuel and give the chain a lube at
> the same time =:O

What are the details and mechanism of crankcase damage when the chain
breaks?
 >> Stay informed about: 1975 CB750 K5 

The Older Gentleman wrote:

> Actually, that was a problem that dogged *all* CB750s until the F2 and
> K7 came along with beefed-up O-ring chains.

Could I replace the chain and sprockets with stouter parts? Maybe some
previous owner has done that already?
 >> Stay informed about: 1975 CB750 K5 

Matt <themattfella RemoveThis @xxyyyzzzz.com> wrote:

> The Older Gentleman wrote:
>
> > Actually, that was a problem that dogged *all* CB750s until the F2 and
> > K7 came along with beefed-up O-ring chains.
>
> Could I replace the chain and sprockets with stouter parts? Maybe some
> previous owner has done that already?

I don't know if the chain and sprockets from the later models will fit.
I don't see why they shouldn't, but it's not a conversion I've ever seen
done.


--
Trophy 1200 750SS TR65 GPz550 CB400F CB125S DT50MX
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....
 >> Stay informed about: 1975 CB750 K5 

Matt wrote:
> The Older Gentleman wrote:
>
> > Actually, that was a problem that dogged *all* CB750s until the F2 and
> > K7 came along with beefed-up O-ring chains.
>
> Could I replace the chain and sprockets with stouter parts? Maybe some
> previous owner has done that already?

I ride a K5 as a daily driver (well, I did until the base gasket
started
leaking. Can't show up at work with my right pantleg oil-soaked, so
it's
parked for the moment). I've got a Tsubaki 530 O-ring chain on it, and
aftermarket sprockets. No problems with the install.

I agree on the brakes, weight, and looks comments, too. I ride it
because
I like the "classicness" of the bike, and don't mind working on old
bikes.

80 mph is about the top you'll want to ride it without a windscreen.

You'll want to look at www.vjmc.org, and wherever SOHC is hanging out
now, I
think it's www.sohc.net.

It's a fun bike, IMO. Far from perfect, just fun.

--
Sandy
 >> Stay informed about: 1975 CB750 K5 

thesewiv wrote:
> Matt wrote:
> > The Older Gentleman wrote:
> >
> > > Actually, that was a problem that dogged *all* CB750s until the F2 and
> > > K7 came along with beefed-up O-ring chains.
> >
> > Could I replace the chain and sprockets with stouter parts? Maybe some
> > previous owner has done that already?
>
> I ride a K5 as a daily driver (well, I did until the base gasket
> started
> leaking. Can't show up at work with my right pantleg oil-soaked, so
> it's
> parked for the moment). I've got a Tsubaki 530 O-ring chain on it, and
> aftermarket sprockets. No problems with the install.
>
> I agree on the brakes, weight, and looks comments, too. I ride it
> because
> I like the "classicness" of the bike, and don't mind working on old
> bikes.
>
> 80 mph is about the top you'll want to ride it without a windscreen.
>
> You'll want to look at www.vjmc.org, and wherever SOHC is hanging out
> now, I
> think it's www.sohc.net.
>
> It's a fun bike, IMO. Far from perfect, just fun.
>

I think that's fair....

I've owned most of the SOHC Honda fours at one time or another. The
very best, from a riding point of view, was the CB650 (believe it or
not). Faster than all but the very fastest 750s, and handled and braked
infinitely better.

The 550s are a good compromise, but they're really thirsty, except for
the four-piper K.

I've still got a 400, which is (IMHO) the best of the lot. It
completely outhandles all the others (with the possible exception of
the 650), is smoother than the others, more economical, and looks just
fantastic (again IMHO). However, it's a finicky little bike, and
requires more frequent maintenance, especially oil changes and carb
balancing. And it doesn't suit the large rider.

Never ridden a 350, nor a 500.
 >> Stay informed about: 1975 CB750 K5 

"thesewiv" <thesewiv.TakeThisOut@gmail.com> wrote in message
news:1129215876.035198.185130@g49g2000cwa.googlegroups.com...
>
> Matt wrote:
>> The Older Gentleman wrote:
>>
>> > Actually, that was a problem that dogged *all* CB750s until the F2 and
>> > K7 came along with beefed-up O-ring chains.
>>
>> Could I replace the chain and sprockets with stouter parts? Maybe some
>> previous owner has done that already?
>
> I ride a K5 as a daily driver (well, I did until the base gasket
> started
> leaking. Can't show up at work with my right pantleg oil-soaked, so
> it's
> parked for the moment). I've got a Tsubaki 530 O-ring chain on it, and
> aftermarket sprockets. No problems with the install.
>
> I agree on the brakes, weight, and looks comments, too. I ride it
> because
> I like the "classicness" of the bike, and don't mind working on old
> bikes.
>
> 80 mph is about the top you'll want to ride it without a windscreen.
>
> You'll want to look at www.vjmc.org, and wherever SOHC is hanging out
> now, I
> think it's www.sohc.net.
>
> It's a fun bike, IMO. Far from perfect, just fun.
>
> --
> Sandy
>


Add a can of radiator stop leak in your crankcase next oil change. I
guarantee it will stop leaking. <G>

Just kidding, folks. DON'T DO AS I SUGGESTED.

I actually heard of a woman doing that to her leaking automatic
transmission. No, I didn't suggest it, either.

Ed Cregger
 >> Stay informed about: 1975 CB750 K5