In the BHP/wheel thread, different Kawa GPz's were discussed, as bikes
worth having / owning again.

I've only once ridden a Kawasaki, a green Z650 demo bike back in 1978,
so I know little about what goes wrong with them. Just saw an ad for an
'84 GPz750, which doesn't look molested, but it has 42 kMiles on the
clock, and is a recent used import, so presumably without service
history. The seller mentions the engine stumbles when cold, and has
suggested carbs /valves as possible repair jobs.

He seller posted a video of it running in the ad:

<https://www.youtube.com/watch?v=V9fpNPf9-uU>

Are any of you able to tell anything about the engine from hearing it
run? The seller also mentioned the flashing red warning light, and said
he didn't know what it meant.

I have enough bikes as it is, so won't be offended of the verdict is
that it's about to self destruct.

--
ts // scrap vehicle to send e-mail
Finally four Boxers!

On Mon, 25 Oct 2021 21:02:30 +0200, exbn-ppin@deaVOLVO.spamcon.org
(ts) wrote:

>In the BHP/wheel thread, different Kawa GPz's were discussed, as bikes
>worth having / owning again.
>
>I've only once ridden a Kawasaki, a green Z650 demo bike back in 1978,
>so I know little about what goes wrong with them. Just saw an ad for an
>'84 GPz750, which doesn't look molested, but it has 42 kMiles on the
>clock, and is a recent used import, so presumably without service
>history. The seller mentions the engine stumbles when cold, and has
>suggested carbs /valves as possible repair jobs.
>
>He seller posted a video of it running in the ad:
>
><https://www.youtube.com/watch?v=V9fpNPf9-uU>
>
>Are any of you able to tell anything about the engine from hearing it
>run? The seller also mentioned the flashing red warning light, and said
>he didn't know what it meant.
>
>I have enough bikes as it is, so won't be offended of the verdict is
>that it's about to self destruct.

Can't tell anything from that. Stumbles under what conditions? Idle,
as shown? Steady low speed riding? Opening the throttle suddenly? High
revs? I'll leave the warning light to SWK.

--

-Pip

Pipl <pluscher@live.co.uk> wrote:
> On Mon, 25 Oct 2021 21:02:30 +0200, exbn-ppin@deaVOLVO.spamcon.org
> (ts) wrote:
>
>>In the BHP/wheel thread, different Kawa GPz's were discussed, as bikes
>>worth having / owning again.
>>
>>I've only once ridden a Kawasaki, a green Z650 demo bike back in 1978,
>>so I know little about what goes wrong with them. Just saw an ad for an
>>'84 GPz750, which doesn't look molested, but it has 42 kMiles on the
>>clock, and is a recent used import, so presumably without service
>>history. The seller mentions the engine stumbles when cold, and has
>>suggested carbs /valves as possible repair jobs.
>>
>>He seller posted a video of it running in the ad:
>>
>><https://www.youtube.com/watch?v=V9fpNPf9-uU>
>>
>>Are any of you able to tell anything about the engine from hearing it
>>run? The seller also mentioned the flashing red warning light, and said
>>he didn't know what it meant.
>>
>>I have enough bikes as it is, so won't be offended of the verdict is
>>that it's about to self destruct.
>
> Can't tell anything from that. Stumbles under what conditions? Idle,
> as shown? Steady low speed riding? Opening the throttle suddenly? High
> revs? I'll leave the warning light to SWK.

I owned an 82 GPz550 and an 81 KZ750, so reasonably familiar with
the Kawasakis bikes of that vintage.

If I'm not mistaken, the only red warning light would be the low oil
pressure light. For that reason alone, I would avoid.

Whoops, just remembered, GPz bikes of that period had a 7th hole
in the top of the battery, which had a electrolye level sensing
electrode. Since aftermarket batteries don't have a suitable hole,
the warning light turns on. The fix involves tying the sensor wire
to the positive terminal of the battery, or a voltage divider (the
hole is in the middle of the cells).

--
FJR1300A, GL1000, KLR650A6F, EX250J9A, DR200SE, Vespa Ciao

Pipl <pluscher@live.co.uk> wrote:
> exbn-ppin@deaVOLVO.spamcon.org (ts) wrote:

> ><https://www.youtube.com/watch?v=V9fpNPf9-uU>
> >
> >Are any of you able to tell anything about the engine from hearing it
> >run? The seller also mentioned the flashing red warning light, and said
> >he didn't know what it meant.
> >
> Can't tell anything from that. Stumbles under what conditions? Idle,
> as shown? Steady low speed riding? Opening the throttle suddenly? High
> revs?

From what was mentioned about the condition, the seller didn't seem to
know much about MC maintenance and/or mechanics [1]

I thought the engine was running a bit "lumpy", which could just be due
to poor carb synchronicing, or some clogged up idle circuits/whatever.

One reason for noticing the ad was that TOG mentioned the Kawa GPz's in
his list 'Seven bikes with long lives'[2] in MCN that surfaced after his
passing; thus I assume the engine was well engineered, and without known
weaknesses that detroyed them after 40 or so kMiles on the clock.

[1]but that could just be intentional
[2] . . "engines with astonishing lifespans" . .
--
ts // scrap vehicle to send e-mail
Finally four Boxers!

Mark Olson <olsonm@tiny.invalid> wrote:
> Whoops, just remembered, GPz bikes of that period had a 7th hole
> in the top of the battery, which had a electrolye level sensing
> electrode. Since aftermarket batteries don't have a suitable hole,
> the warning light turns on. The fix involves tying the sensor wire
> to the positive terminal of the battery, or a voltage divider (the
> hole is in the middle of the cells).

Many thanks, Mark - that's the kind of information that can be hard to
find for the uninformed owner who relies on getting their bikes serviced
in garages, whose staff that knew retired a decade ago :-)

--
ts // scrap vehicle to send e-mail
Finally four Boxers!

On Tue, 26 Oct 2021 12:05:38 +0200, exbn-ppin@deaVOLVO.spamcon.org
(ts) wrote:

>
>One reason for noticing the ad was that TOG mentioned the Kawa GPz's in
>his list 'Seven bikes with long lives'[2] in MCN that surfaced after his
>passing; thus I assume the engine was well engineered, and without known
>weaknesses that detroyed them after 40 or so kMiles on the clock.
>
>[1]but that could just be intentional
>[2] . . "engines with astonishing lifespans" . .

AIUI air-cooled GPz's are just Zs in a posh frock.

My Z650 ran dry of oil in the south of France in August, I coasted
into a petrol station, blew the holiday budget on 4 litres of 20/50,
cooled it down with a hose, filled it up and rode home. No rattles or
bangs, and it was still running several years later. It had over 50k
on it when I p/x'd for a proper GPz.
--
Salad Dodger
1690 FLHTK;GL1800D
Previously ...
CB1300SA8;GL1800A6;GL1500SEV;CBR1100XXX;
CBR1000FL;CBX1000Z;GPz750R;Z750E1;Z650C2;
KH500A8;KH250B3;TS250c;TS185c.

Mark Olson wrote:

> If I'm not mistaken, the only red warning light would be the low oil
> pressure light. For that reason alone, I would avoid.

It's the battery warning light.

Kawasakis of that era had a sensor inserted in one of the battery cells
to warn of dead battery/low acid.

If that sensor isn't in the acid (because it's a modern sealed battery)
it thinks there's a problem.

I fixed it on my GT750 with some insulating tape - in my case the
sensor had corroded [1] and fallen off.
http://sweller.co.uk/gt750/dscf5040.html

[1] funny that.

--
Simon

ts wrote:

> The seller also mentioned the flashing red warning light, and said
> he didn't know what it meant.

Battery warning light - see my reply to Mark Olson.

I fixed the problem on my GT750 like this:
http://sweller.co.uk/gt750/dscf5040.html

--
Simon

Mark Olson wrote:

> Whoops, just remembered, GPz bikes of that period had a 7th hole
> in the top of the battery, which had a electrolye level sensing
> electrode. Since aftermarket batteries don't have a suitable hole,
> the warning light turns on. The fix involves tying the sensor wire
> to the positive terminal of the battery, or a voltage divider (the
> hole is in the middle of the cells).

I hadn't read this bit...

--
Simon

sweller <sweller@mztech.fsnet.co.uk> wrote:
> Mark Olson wrote:
>
>> If I'm not mistaken, the only red warning light would be the low oil
>> pressure light. For that reason alone, I would avoid.
>
> It's the battery warning light.

As I pointed out, in the next paragraph, which you snipped.

> Kawasakis of that era had a sensor inserted in one of the battery cells
> to warn of dead battery/low acid.

Indeed they did.

--
FJR1300A, GL1000, KLR650A6F, EX250J9A, DR200SE, Vespa Ciao

sweller <sweller@mztech.fsnet.co.uk> wrote:
> Mark Olson wrote:
>
>> Whoops, just remembered, GPz bikes of that period had a 7th hole
>> in the top of the battery, which had a electrolye level sensing
>> electrode. Since aftermarket batteries don't have a suitable hole,
>> the warning light turns on. The fix involves tying the sensor wire
>> to the positive terminal of the battery, or a voltage divider (the
>> hole is in the middle of the cells).
>
> I hadn't read this bit...

And I hadn't read this either. Whoops.

--
FJR1300A, GL1000, KLR650A6F, EX250J9A, DR200SE, Vespa Ciao

Salad Dodger <salad.dodger@idnet.com> wrote:
> On Tue, 26 Oct 2021 12:05:38 +0200, exbn-ppin@deaVOLVO.spamcon.org
> (ts) wrote:
>
>>
>>One reason for noticing the ad was that TOG mentioned the Kawa GPz's in
>>his list 'Seven bikes with long lives'[2] in MCN that surfaced after his
>>passing; thus I assume the engine was well engineered, and without known
>>weaknesses that detroyed them after 40 or so kMiles on the clock.
>>
>>[1]but that could just be intentional
>>[2] . . "engines with astonishing lifespans" . .
>
> AIUI air-cooled GPz's are just Zs in a posh frock.

Up to a point, Lord Copper.

The fellow I bought my '82 GPz550 from was a true motorhead and he
told me the GPz differed from the cooking Z in that it had slightly
hotter cams, plus the intake and exhaust ports were polished. I can't
say from personal experience, but I do know that on the day he picked
it up, he bought a head gasket at the parts counter so that he could
remove the head when he got home, because he wanted to have a look
at the combustion chambers...

> My Z650 ran dry of oil in the south of France in August, I coasted
> into a petrol station, blew the holiday budget on 4 litres of 20/50,
> cooled it down with a hose, filled it up and rode home. No rattles or
> bangs, and it was still running several years later. It had over 50k
> on it when I p/x'd for a proper GPz.

I also had a '77 KZ650B1 and it never gave me a lick of trouble.

--
FJR1300A, GL1000, KLR650A6F, EX250J9A, DR200SE, Vespa Ciao

Mark Olson wrote:

> > I hadn't read this bit...
>
> And I hadn't read this either. Whoops.

What a team!

--
Simon

On Mon, 25 Oct 2021 21:02:30 +0200, exbn-ppin@deaVOLVO.spamcon.org
(ts) wrote:

>In the BHP/wheel thread, different Kawa GPz's were discussed, as bikes
>worth having / owning again.

They are

>I've only once ridden a Kawasaki, a green Z650 demo bike back in 1978,

The GPz750 is a very direct descendent of that z650. Pretty much the
same engine, apart from the increase in capacity, and some detail
changes (electronic ignition, hy-vo camchain, etc)

>but it has 42 kMiles on the clock

It's damn near 40 years old, so in no way is that a high mileage

>The seller mentions the engine stumbles when cold, and has
>suggested carbs /valves as possible repair jobs.

The combination of age and its mileage means its probably been stored
for period, so the first thing I'd look at is carbs. And, if I were
buying it, I'd change the oil and check the valve clearances soon as a
matter of course, anyway

>He seller posted a video of it running in the ad:
><https://www.youtube.com/watch?v=V9fpNPf9-uU>

Seems fine. Bit more exhause noise than I might expect, but I doubt
the silencers do as much silencing now as they did in 1984

>Are any of you able to tell anything about the engine from hearing it
>run? The seller also mentioned the flashing red warning light, and said
>he didn't know what it meant.

This has been covered elsewhere in the thread. For further reference,
there's an LCD display on the top of the tank, which includes the fuel
gauge, and give a more detail of the cause if the red light flashes
e.g. oil, battery, etc.

I think it's bloody lovely. How much is he asking for it?
--
Champ
neal at champ dot org dot uk

I don't know, but I been told
You never slow down, you never grow old

Champ wrote:

> > but it has 42 kMiles on the clock
>
> It's damn near 40 years old, so in no way is that a high mileage

My four year old Triumph nearly has that.

--
Simon

Salad Dodger <salad.dodger@idnet.com> wrote:

> My Z650 ran dry of oil in the south of France in August, I coasted
> into a petrol station, blew the holiday budget on 4 litres of 20/50,
> cooled it down with a hose, filled it up and rode home. No rattles or
> bangs, and it was still running several years later. It had over 50k
> on it when I p/x'd for a proper GPz.

Impressive. The Z650 ancestry presumably makes the cams[1] less likely
to wear out the heads due to poor lubrication, unlike some Hondas made
at the same time.

[1] saw on motorcyclespecs.za that the GPz cams also run directly in the
heads, without bearings
--
ts // scrap vehicle to send e-mail
Finally four Boxers!

Champ <neal@champ.org.uk> wrote:

> On Mon, 25 Oct 2021 21:02:30 +0200, exbn-ppin@deaVOLVO.spamcon.org
> (ts) wrote:
>
> >In the BHP/wheel thread, different Kawa GPz's were discussed, as bikes
> >worth having / owning again.
>
> They are
>
> >I've only once ridden a Kawasaki, a green Z650 demo bike back in 1978,
>
> The GPz750 is a very direct descendent of that z650. Pretty much the
> same engine, apart from the increase in capacity, and some detail
> changes (electronic ignition, hy-vo camchain, etc)
>
> >but it has 42 kMiles on the clock
>
> It's damn near 40 years old, so in no way is that a high mileage
>
> >The seller mentions the engine stumbles when cold, and has
> >suggested carbs /valves as possible repair jobs.
>
> The combination of age and its mileage means its probably been stored
> for period, so the first thing I'd look at is carbs. And, if I were
> buying it, I'd change the oil and check the valve clearances soon as a
> matter of course, anyway
>
> >He seller posted a video of it running in the ad:
> ><https://www.youtube.com/watch?v=V9fpNPf9-uU>
>
> Seems fine. Bit more exhause noise than I might expect, but I doubt
> the silencers do as much silencing now as they did in 1984
>
> >Are any of you able to tell anything about the engine from hearing it
> >run? The seller also mentioned the flashing red warning light, and said
> >he didn't know what it meant.
>
> This has been covered elsewhere in the thread. For further reference,
> there's an LCD display on the top of the tank, which includes the fuel
> gauge, and give a more detail of the cause if the red light flashes
> e.g. oil, battery, etc.

Thanks! The seller got back to me and mentioned the previous owner had
several rubber parts (inlet ducts, valve stem seals) replaced, which
could be since the fitted bits had perished after storage. No service
history though, as I suspected.

> I think it's bloody lovely. How much is he asking for it?

Around £ 1400 in my local currency. That said, I saw a couple of
KZ1000's listed at 11 and 13 k£ - which presumably reflects both the
local high tax on vehicles here[1], as well as a collector bike status.
Another GPz 750 was listed at k£3.9, I think that owner is just testing
the market.

[1] for comparison, I checked and saw that a new Ducati Supersport 950 S
is listed at k£ 19 here.
--
ts // scrap vehicle to send e-mail
Finally four Boxers!

On Thu, 28 Oct 2021 21:36:45 +0200, exbn-ppin@deaVOLVO.spamcon.org
(ts) wrote:

>Salad Dodger <salad.dodger@idnet.com> wrote:
>
>> My Z650 ran dry of oil in the south of France in August, I coasted
>> into a petrol station, blew the holiday budget on 4 litres of 20/50,
>> cooled it down with a hose, filled it up and rode home. No rattles or
>> bangs, and it was still running several years later. It had over 50k
>> on it when I p/x'd for a proper GPz.

>Impressive. The Z650 ancestry presumably makes the cams[1] less likely
>to wear out the heads due to poor lubrication, unlike some Hondas made
>at the same time.

>[1] saw on motorcyclespecs.za that the GPz cams also run directly in the
>heads, without bearings

Pretty much every single Japanese bike, that I'm aware of, runs the
cams without bearings. Including every Kawasaki
--
Champ
neal at champ dot org dot uk

I don't know, but I been told
You never slow down, you never grow old

On Thu, 28 Oct 2021 21:36:46 +0200, exbn-ppin@deaVOLVO.spamcon.org
(ts) wrote:

>> I think it's bloody lovely. How much is he asking for it?

>Around £ 1400 in my local currency. That said, I saw a couple of
>KZ1000's listed at 11 and 13 k£ - which presumably reflects both the
>local high tax on vehicles here[1], as well as a collector bike status.
>Another GPz 750 was listed at k£3.9, I think that owner is just testing
>the market.

GPz750s are in s completely different segment of classic/collectible
that z1000s, so the prices bear no comparison. Z1000s have been worth
serious money for years. The GPz is not, and will never be, as
desirable.

But, that's not to say that it isn't still a good bike, and definitely
worth 1400 quid
--
Champ
neal at champ dot org dot uk

I don't know, but I been told
You never slow down, you never grow old

On Fri, 29 Oct 2021 11:38:21 +0100, Champ <neal@champ.org.uk> wrote:

>Pretty much every single Japanese bike, that I'm aware of, runs the
>cams without bearings. Including every Kawasaki

I only ever dismantled the top end on one bike, my XT500, back in 1979
or so. If memory serves me I'm pretty sure it had ball bearing races
at each end of the cam.

So maybe it's the exception, I dunno, but I suspect it would also be
true at least of other related Yamaha singles and V twins (which were
in effect two XT/SR barrels and top ends bolted onto a single crank).

--
Ace
http://www.chaletbeauroc.com/

On Fri, 29 Oct 2021 13:21:11 +0200, Ace <Ace@ch.com> wrote:

>On Fri, 29 Oct 2021 11:38:21 +0100, Champ <neal@champ.org.uk> wrote:
>
>>Pretty much every single Japanese bike, that I'm aware of, runs the
>>cams without bearings. Including every Kawasaki
>
>I only ever dismantled the top end on one bike, my XT500, back in 1979
>or so. If memory serves me I'm pretty sure it had ball bearing races
>at each end of the cam.

Google says IDRC.

Anyway, being pedantic, it's never true to say that the cams ran
without bearings. A plain bearing is still a bearing, after all.

--
Ace
http://www.chaletbeauroc.com/

On Fri, 29 Oct 2021 13:28:21 +0200, Ace <Ace@ch.com> wrote:

>On Fri, 29 Oct 2021 13:21:11 +0200, Ace <Ace@ch.com> wrote:
>
>>On Fri, 29 Oct 2021 11:38:21 +0100, Champ <neal@champ.org.uk> wrote:
>>
>>>Pretty much every single Japanese bike, that I'm aware of, runs the
>>>cams without bearings. Including every Kawasaki
>>
>>I only ever dismantled the top end on one bike, my XT500, back in 1979
>>or so. If memory serves me I'm pretty sure it had ball bearing races
>>at each end of the cam.
>
>Google says IDRC.
>
>Anyway, being pedantic, it's never true to say that the cams ran
>without bearings. A plain bearing is still a bearing, after all.

Yeah, the related SR500 lumps had ballraces.

Honda CD185 Benlys had cam bushes that could quite readily go oval if
the engine wasn't serviced properly.

--

-Pip

On Fri, 29 Oct 2021 22:44:18 +0100, Pipl <pluscher@live.co.uk> wrote:

>>On Fri, 29 Oct 2021 13:21:11 +0200, Ace <Ace@ch.com> wrote:

>>>I only ever dismantled the top end on one bike, my XT500, back in 1979
>>>or so. If memory serves me I'm pretty sure it had ball bearing races
>>>at each end of the cam.
>
>Yeah, the related SR500 lumps had ballraces.

Related? 100% identical.

I was more thinking of the TR1 (XV1000) which was effectively two
XT/SR engines bolted together. Not sure if the Virago range followed
suit as well.

--
Ace
http://www.chaletbeauroc.com/

On Sat, 30 Oct 2021 01:26:17 +0200, Ace <Ace@ch.com> wrote:

>On Fri, 29 Oct 2021 22:44:18 +0100, Pipl <pluscher@live.co.uk> wrote:
>
>>>On Fri, 29 Oct 2021 13:21:11 +0200, Ace <Ace@ch.com> wrote:
>
>>>>I only ever dismantled the top end on one bike, my XT500, back in 1979
>>>>or so. If memory serves me I'm pretty sure it had ball bearing races
>>>>at each end of the cam.
>>
>>Yeah, the related SR500 lumps had ballraces.
>
>Related? 100% identical.

Not quite. The XT had a different alternator and detail differences in
the ignition system, I believe.

>I was more thinking of the TR1 (XV1000) which was effectively two
>XT/SR engines bolted together. Not sure if the Virago range followed
>suit as well.

I quite liked those. But not enough to buy one, even if I could have
afforded it.

--

-Pip

On Sat, 30 Oct 2021 17:59:50 +0100, Pipl <pluscher@live.co.uk> wrote:

>On Sat, 30 Oct 2021 01:26:17 +0200, Ace <Ace@ch.com> wrote:
>
>>On Fri, 29 Oct 2021 22:44:18 +0100, Pipl <pluscher@live.co.uk> wrote:
>>
>>>>On Fri, 29 Oct 2021 13:21:11 +0200, Ace <Ace@ch.com> wrote:
>>
>>>>>I only ever dismantled the top end on one bike, my XT500, back in 1979
>>>>>or so. If memory serves me I'm pretty sure it had ball bearing races
>>>>>at each end of the cam.
>>>
>>>Yeah, the related SR500 lumps had ballraces.
>>
>>Related? 100% identical.
>
>Not quite. The XT had a different alternator and detail differences in
>the ignition system, I believe.

Dynamo, ITYF.

Yeah, sure, now I come to think about it there were some minor
differences, most notably a heavier flywheel in the SR, making the XT
much more easily revving.

I loved that bike, probably the only one I wish I hadn't got rid of.
YLG 7S, where are you now?[1]

[1] Not on the road, for sure; but someone kept it alive until 1992,
at least, according to dvla.

--
Ace
http://www.chaletbeauroc.com/