Engine tuning as a result of changing exhaust system
Adam Gamsa
I have recently bought an '87 Kwak GPz305 which is standard except for
the exhaust. For those who don't know the bike, it is a 2-cylinder
air-cooled 4-stroke, which comes with a pair of exhaust pipes. In '90
the owner replaced the exhaust with a Motad 2-into-1 system. It was
fitted by a garage in Croydon. I was wondering what adjustments you
would have to make to the engine to accommodate this new exhaust system.
In particular, if I were to be able to source a replacement pair of
'original' pipes, what would need to be undone in the way of tuning?
This isn't something I plan to do myself, so I'm asking more out of
curiosity than anything else, but any advice would be very welcome!
Thanks folks,
Adam
JB
"Adam Gamsa" <adam.g...@linacre.ox.ac.uk> wrote in message
news:euqgng$4bj$1...@frank-exchange-of-views.oucs.ox.ac.uk...
_no_ changes needed to be made to carburation at all. Depending on what bike
you fitted them to, there were often some flat spots in the mid-range
though.
On a GPz305 I doubt you'd notice much difference between the motad and
standard system anyway.
JB
Porridgewog SV1k
"Adam Gamsa" <adam.g...@linacre.ox.ac.uk> wrote in message
news:euqgng$4bj$1...@frank-exchange-of-views.oucs.ox.ac.uk...
From what I remember, Motads are a direct replacement and don't necessitate
any rejetting of the carbs. It's only when you upset the air/fuel balance
(like fitting race cans) that you need to up the jet sizes to prevent a lean
running condition. What is wrong with the way your bike runs with the
Motad?
Champ
While there is a very slight possibility that the carbs may have been
re-jetted for the motad, this is really rather unlikely, and anyway
the change would have been very marginal.
You'll be safe to fit an original exhaust.
The more amazing thing is that your 305 still has a working
crankshaft...
--
Champ
ZX10R
GPz750turbo
neal at champ dot org dot uk
Porridgewog SV1k
"Porridgewog SV1k" <f.o@d> wrote in message
> What is wrong with the way your bike runs with the Motad?
(oops, bad form etc)
Ok, I just re-read your post - you think that the jets might have already
been changed to accommodate the Motad and that fitting OE cans will need the
jets changing back. I very much doubt that they'll have been changed.
Adam Gamsa
No worries! I'm just interested. I'm happy with the way the bike runs
with the Motad system. Is rejetting the carbs the only thing which
people need to do when fitting different exhaust systems, then?
Adam Gamsa
Thanks for your help! The bike has only done 11k miles and has been
garaged for its entire life, so is in good nick!
Lozzo
Change the oil and filter every 3000 miles using a good quality semi-
synth oil and a genuine oil filter, service the engine regularly and
it'll last forever. If you don't bother keeping to that schedule start
looking for a new camshaft and cylinder head.
--
Lozzo
Triumph Daytona 955i SE (Black with added black bits)
Suzuki Bandit 600S (Green with added shit bits)
Yamaha SR250 Delusion (It's "Special")
I ride way too fast to worry about cholestorol.
Adam Gamsa
Thanks, I will - it sounds easier than finding parts =) Anyone know
where I can get hold of a service manual/Haynes manual?
Lozzo
> Lozzo said the following on 02/04/07 10:41:
> > Change the oil and filter every 3000 miles using a good quality semi-
> > synth oil and a genuine oil filter, service the engine regularly and
> > it'll last forever. If you don't bother keeping to that schedule start
> > looking for a new camshaft and cylinder head.
> >
>
> Thanks, I will - it sounds easier than finding parts =) Anyone know
> where I can get hold of a service manual/Haynes manual?
Ebay
Brownz (Mobile)
> Adam Gamsa says...
>> Lozzo said the following on 02/04/07 10:41:
>
>>> Change the oil and filter every 3000 miles using a good quality
>>> semi- synth oil and a genuine oil filter, service the engine
>>> regularly and it'll last forever. If you don't bother keeping to
>>> that schedule start looking for a new camshaft and cylinder head.
>>>
>>
>> Thanks, I will - it sounds easier than finding parts =) Anyone know
>> where I can get hold of a service manual/Haynes manual?
>
> Ebay
Thats the one with the elastic band instead of a chain right ?
--
Cheerz - Brownz
http://www.brownz.org/
Tim
Gamsa <adam.g...@linacre.ox.ac.uk> writes
>Dear all,
>
>I have recently bought an '87 Kwak GPz305 which is standard except for
>the exhaust. For those who don't know the bike, it is a
pile of shite.
Sorry if that offends but I had two friends who got one each not long
after they came out. Endless returns to the shop for fix after fix.
Tim
<ne...@champ.org.uk> writes
or output shaft as the keys failed and the bike made lots of churning
noises and 0 mph.
--
Tim
http://www.pitfieldbeershop.co.uk/
Bear
Which leads me to thinking about "who makes the greatest number of
disasters?" ... and "how big a disaster were they?" ... the GPz305 is a
pup, for sure, but it does open the door to some really, *really* crap
bikes ...
At least with Kawasaki you don't get that many utter disasters. The
GPz305 was one, the KR1S another ... and then there's ... er ... well
I'm sure a few more will pop up shortly, whereas with Honda ...
Jesus, there aren't enough days in the year ... VF750 ... cams that
hated everyone, CX500 handling & cam chain woes, CB750F/CB900F oil
starvation when elevated, early 750s snapping camshafts, cam chain
tensioners on almost everything for a decade, the "enclosed, ventilated
front disc brake", someone knowledgeable about old shit, like TOG or
Lozzo, will be able to fill half a page of post with a list of clangers
... go on chaps, go for it :)
And Triumph (even in modern guise) don't do so bad either ... Daytona
frames, TT600 fuelling, early Trident headstocks ... didn't early Tigers
come back for something too?
Then there's Yam, who do the whole gamut of disasters in one bike: the
XS750 triple ... a bike so bad that it used to take up almost half a
column-page to itself in UBG in the "problems" section ... I can't
recall if it was UBG or someone else who then replaced all the text with
"almost everything". There's a strong case for including a shedload of
2 strokes from that era too, but Lozzo will hire someone to kill me ...
Suzuki? Well nowadays the gixer 750 is a paragon, but the first ones
were "blessed" with con rods suffering from both claustrophobia and
wanderlust, then there's the 16 inch front wheel tomfoolery of the
GSX550/750 ... mmmmmm handling-tastic ... and the RG125, which didn't
have enough steering lock to pass the test it was built to help you
pass, etc etc
Come on folks, let's remind younger riders why they're lucky sods -
bikes today are pretty good, at the very least, or most of them are.
Other nominations ...
<this space left blank for Lozzo to add "THE ENTIRE BMW RANGE, EVER">
--
Bear
Champ
wrote:
True enough, but if it's still running now, then it might be presumed
to be ok.
--
Champ
ZX10R | GPz750turbo | GSX-R 600 racer
My advice as your attorney is to buy a motorcycle
To email me, neal at my domain should work.
Tim
<ne...@champ.org.uk> writes
>On Mon, 2 Apr 2007 20:34:31 +0100, Tim <t...@nospam.osvif.demon.co.uk>
>wrote:
>
>>In message <euqgng$4bj$1...@frank-exchange-of-views.oucs.ox.ac.uk>, Adam
>>Gamsa <adam.g...@linacre.ox.ac.uk> writes
>>>Dear all,
>>>
>>>I have recently bought an '87 Kwak GPz305 which is standard except for
>>>the exhaust. For those who don't know the bike, it is a
>>
>>pile of shite.
>>
>>Sorry if that offends but I had two friends who got one each not long
>>after they came out. Endless returns to the shop for fix after fix.
>
>True enough, but if it's still running now, then it might be presumed
>to be ok.
Statistically there must be one I suppose.
--
Tim
http://www.pitfieldbeershop.co.uk/
Lozzo
> At least with Kawasaki you don't get that many utter disasters. The
> GPz305 was one, the KR1S another ... and then there's ... er ... well
> I'm sure a few more will pop up shortly, whereas with Honda ...
If looked after according to the service schedule the GPZ305 is a bloody
reliable bike, trouble is not a lot of them were serviced regularly
enough, which got them a nasty reputation for blowing up. KR1s and the
KR1Ss were just fucking shite through and through, no matter what you
did to them.
> Jesus, there aren't enough days in the year ... VF750 ... cams that
> hated everyone, CX500 handling & cam chain woes, CB750F/CB900F oil
> starvation when elevated, early 750s snapping camshafts, cam chain
> tensioners on almost everything for a decade, the "enclosed, ventilated
> front disc brake", someone knowledgeable about old shit, like TOG or
> Lozzo, will be able to fill half a page of post with a list of clangers
> ... go on chaps, go for it :)
Honda just couldn't make a reliable camchain tensioner for quite some
time. I didn't mind the enclosed disc on my VF400, it taught me to ride
smoother and not use the bloody thing. I ended up becoming incredibly
quick and hardly braking.
> And Triumph (even in modern guise) don't do so bad either ... Daytona
> frames, TT600 fuelling, early Trident headstocks ... didn't early Tigers
> come back for something too?
Daytona 675 oil consumption, Daytona and Sprint 955i fuel couplings and
a few others come to mind.
> Then there's Yam, who do the whole gamut of disasters in one bike: the
> XS750 triple ... a bike so bad that it used to take up almost half a
> column-page to itself in UBG in the "problems" section ... I can't
> recall if it was UBG or someone else who then replaced all the text with
> "almost everything".
They really were horrible bikes.
> There's a strong case for including a shedload of
> 2 strokes from that era too, but Lozzo will hire someone to kill me ...
The first of the powervalves, like the one mr P-W Buckley owns were evil
handling bastards. I refer sir to this post I once made :
http://groups.google.co.uk/group/uk.rec.motorcycles/browse_thread/thread
/491d77651ed762f6/b655ede50a36afe6?lnk=st&q=&rnum=1
&hl=en#b655ede50a36afe6
> Other nominations ...
>
> <this space left blank for Lozzo to add "THE ENTIRE BMW RANGE, EVER">
<small voice>
I don't like BMWs
</sm>
SD
wrote:
>In article <eSYczPGHrVEGFww$@nospam.osvif.demon.co.uk>, Tim says...
>> In message <euqgng$4bj$1...@frank-exchange-of-views.oucs.ox.ac.uk>, Adam
>> Gamsa <adam.g...@linacre.ox.ac.uk> writes
>> >Dear all,
>> >
>> >I have recently bought an '87 Kwak GPz305 which is standard except for
>> >the exhaust. For those who don't know the bike, it is a
>>
>> pile of shite.
>>
>> Sorry if that offends but I had two friends who got one each not long
>> after they came out. Endless returns to the shop for fix after fix.
>
>Which leads me to thinking about "who makes the greatest number of
>disasters?" ... and "how big a disaster were they?" ... the GPz305 is a
>pup, for sure, but it does open the door to some really, *really* crap
>bikes ...
>
>At least with Kawasaki you don't get that many utter disasters.
Sounds like someone's forgotten the two stroke triples.
> The
>GPz305 was one, the KR1S another ... and then there's ... er ... well
>I'm sure a few more will pop up shortly, whereas with Honda ...
Well, they still haven't sussed carb icing after 20 years.
GPz900/750R at camshafts/tensioners.
>Jesus, there aren't enough days in the year ... VF750 ... cams that
>hated everyone, CX500 handling & cam chain woes, CB750F/CB900F oil
>starvation when elevated, early 750s snapping camshafts, cam chain
>tensioners on almost everything for a decade, the "enclosed, ventilated
>front disc brake", someone knowledgeable about old shit, like TOG or
>Lozzo, will be able to fill half a page of post with a list of clangers
>... go on chaps, go for it :)
Partly the result of having a slightly bigger list of models to choose
from.
>
>And Triumph (even in modern guise) don't do so bad either ... Daytona
>frames, TT600 fuelling, early Trident headstocks ... didn't early Tigers
>come back for something too?
>
>Then there's Yam, who do the whole gamut of disasters in one bike: the
>XS750 triple ... a bike so bad that it used to take up almost half a
>column-page to itself in UBG in the "problems" section ... I can't
>recall if it was UBG or someone else who then replaced all the text with
>"almost everything". There's a strong case for including a shedload of
>2 strokes from that era too, but Lozzo will hire someone to kill me ...
That horrible 550 V-twin - XZ?
>
>Suzuki? Well nowadays the gixer 750 is a paragon, but the first ones
>were "blessed" with con rods suffering from both claustrophobia and
>wanderlust, then there's the 16 inch front wheel tomfoolery of the
>GSX550/750 ... mmmmmm handling-tastic ... and the RG125, which didn't
>have enough steering lock to pass the test it was built to help you
>pass, etc etc
--
| ___ Salad Dodger
|/ \
_/_____\_ GL1500SEV/CBR1100XXX/CBX1000Z
|_\_____/_| ..88045../..23727.../..31893.
(>|_|_|<) TPPFATUICG#7 DIAABTCOD#9 WG*
|__|_|__| BOTAFOT #70 BOTAFOF #09 PM#5
\ |^| / IbW#0 & KotIbW# BotTOS#6 GP#4
\|^|/ ANORAK#17 IbB#4 YTC#4 two#11
'^' RBR Clues: 00 Pts:0000 Miles:0000
Bear
> On Mon, 2 Apr 2007 21:22:05 +0100, Bear <bastard...@gmail.com>
> wrote:
>
> >In article <eSYczPGHrVEGFww$@nospam.osvif.demon.co.uk>, Tim says...
> >> In message <euqgng$4bj$1...@frank-exchange-of-views.oucs.ox.ac.uk>, Adam
> >> Gamsa <adam.g...@linacre.ox.ac.uk> writes
> >> >Dear all,
> >> >
> >> >I have recently bought an '87 Kwak GPz305 which is standard except for
> >> >the exhaust. For those who don't know the bike, it is a
> >>
> >> pile of shite.
> >>
> >> Sorry if that offends but I had two friends who got one each not long
> >> after they came out. Endless returns to the shop for fix after fix.
> >
> >Which leads me to thinking about "who makes the greatest number of
> >disasters?" ... and "how big a disaster were they?" ... the GPz305 is a
> >pup, for sure, but it does open the door to some really, *really* crap
> >bikes ...
> >
> >At least with Kawasaki you don't get that many utter disasters.
>
> Sounds like someone's forgotten the two stroke triples.
They weren't disasters! How very dare you!
They were ... er ... hmmmmmm ... "different".
> > The
> >GPz305 was one, the KR1S another ... and then there's ... er ... well
> >I'm sure a few more will pop up shortly, whereas with Honda ...
>
> Well, they still haven't sussed carb icing after 20 years.
Yes they have ... their fuel injected bikes don't do it :)
> GPz900/750R at camshafts/tensioners.
Rarely though; hardly a disaster, and some GPz900s have done mental
miles.
> >Jesus, there aren't enough days in the year ... VF750 ... cams that
> >hated everyone, CX500 handling & cam chain woes, CB750F/CB900F oil
> >starvation when elevated, early 750s snapping camshafts, cam chain
> >tensioners on almost everything for a decade, the "enclosed, ventilated
> >front disc brake", someone knowledgeable about old shit, like TOG or
> >Lozzo, will be able to fill half a page of post with a list of clangers
> >... go on chaps, go for it :)
>
> Partly the result of having a slightly bigger list of models to choose
> from.
And fitting the same crap camchain tensioner in most of them.
> >And Triumph (even in modern guise) don't do so bad either ... Daytona
> >frames, TT600 fuelling, early Trident headstocks ... didn't early Tigers
> >come back for something too?
> >
> >Then there's Yam, who do the whole gamut of disasters in one bike: the
> >XS750 triple ... a bike so bad that it used to take up almost half a
> >column-page to itself in UBG in the "problems" section ... I can't
> >recall if it was UBG or someone else who then replaced all the text with
> >"almost everything". There's a strong case for including a shedload of
> >2 strokes from that era too, but Lozzo will hire someone to kill me ...
>
> That horrible 550 V-twin - XZ?
XS1100 also springs to mind. Horrible, though not really what I'd call
a disaster.
--
Bear
TMack
I have a genuine Kawasaki Service Manual for the GPZ305 - contact me by
email if you are interested (watch out for the spamtrap in my email address)
--
Tony
'04 XL1200C, '95 LS650
OMF#24
The Older Gentleman
<snip>
Every manufacturer has its bad moments. When corners cut in development,
in the rush to get the models out, results in catastrophe.
Honda's such nadir was the early/mid-1980s.
BMW's is now.
Triumph's was a couple, maybe three or four, years ago, but I think they
recognised the danger signs and pulled themselves together just in time.
Ducati... well, only between 1970 and 2007.
Moto-Guzzi - the mid-1980s, and a decade thereafter, when *every* model
was shite.
Suzuki - the interregnum between the old GS series and the GSXR. Think
GSX fours, with their terrible electrics, the ill-fated Turbo, the crap
early vee-twins, the leccy windscreen tourer with its supermarket
trolley-sized wheels, the GR650 twin with its centrifugal flywheel
crank......
Kawasaki - beyond the occasional lemon, they have rarely put a foot
wrong, and it's hard to point at a duff Kawasaki launched since, say,
1984. GPZ1000R, KLR650, that's about it.
Laverda - everything, following the re-introduction of the brand in the
1990s. An unrivalled catalogue of mechanical catastrophe, irate dealers,
desperate press, and despondent customers. I suppose they kept the RAC
and AA in business.
Yamaha - the early 19080s, when they insanely dropped the 50 twin in
favour of a series of crap vee-twins and triples and lacklustre fours,
with the possible exception of the XJ650. Redeemed by their launch of
the RD350.
Very few manufacturers build truly crap bikes these days. But the
lacklustre machine, that should never have been let off the
drawing-board, and is then priced so far above the opposition that
nobody buys it, is still with us. Oh, we're back in the Z1000 thread.
--
BMW K1100LT 750SS CB400F CD250 Z650
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....
platypus
>
> Laverda - everything, following the re-introduction of the brand in
> the 1990s. An unrivalled catalogue of mechanical catastrophe, irate
> dealers, desperate press, and despondent customers. I suppose they
> kept the RAC and AA in business.
Fair play, at least they sold one of the wretched things to Doc Gonz0.
--
platypus
"Merely corroborative detail, intended to
give artistic verisimilitude to an otherwise
bald and unconvincing narrative.”
Adam Gamsa
Oh dear, sounds like I might have invested my hard earned £400 in a
stinker. Oh well, it should still do what I intended it to - namely to
serve as a machine to learn about how 4-strokes work. I just won't be as
distressed if it doesn't run when I put it all back together. That and
finding a buyer when I want to sell it on...
darsy
wrote:
actually, I think Ebay is shaft-driven.
--
d.
Hog
> Ducati... well, only between 1970 and 2007.
Oi!!!!
--
Hog
'03 ST4S '96 Bastard12 '89 R100RS '81 XS650 '78 RD400
Tim
<1hvyt43.199meja1mhd67hN%chateau.murra...@dsl.pipex.com>, The
Older Gentleman <chateau.murra...@dsl.pipex.com> writes
>SD <salad....@dsl.pipex.com> wrote:
>
><snip>
>
>Every manufacturer has its bad moments. When corners cut in development,
>in the rush to get the models out, results in catastrophe.
>
>Yamaha - the early 19080s, when they insanely dropped the 50 twin in
you are Fry from Futurama aren't you?
--
Tim
http://www.pitfieldbeershop.co.uk/