A problem for your jollification.

I have been fettling the GS in an attempt to improve the running[1]
since I put the K&N filter on and have a little issue with the engine
not slowing down very quickly when I close the throttle. I am fairly
confident it is probably running a bit lean but could this be the cause
of it? If not then what, the sliders seem free enough.



[1 ]Finding out one of the coils was a bit iffy certainly helped the
poor starting issues.

 

If the slides are free then it's definitely mixture - lean running
usually causes the revs to rise (eg if you leave it on tickover with the
fuel tap switched off, if fitted, the revs will rise before it conks out.)

HTH

 

Isn't that the sign of an over-rich mixture?

 

Which is almost certainly not standard. That much I am sure of.

The LHS particularly had been well fucked about with before I got the
bike and most of what I have done since has been putting it right rather
than trying to improve performance.

The only thing I am not too sure about is the head on the fuel supply
and how much difference it would make. My temporary rig is gaffer taped
to the bars and so is a foot or so higher than with a tank on, which
would tend to make it rich.

I just want to make sure it is as right as I can get it before I commit
to putting the tank back on. It is far too much faffing around to be
taking that on and off a dozen more times for bugger all improvement.

And air cooled engines don't like running for too long while you play
either so it is short bursts of annoying the neighbours and many tea
breaks, which don't help. Colostomy bags don't come cheap.

 

One was but has been retired. The three I have left are all fine as far
as I can see.

 

The throttle cable is sticking.

 

I don't think so but it is only single cable operation so I cannot be
sure. It is just like a sticky slider but it ain't that, which is why I
am asking if extreme mixture could be the issue.

 

No.

 

If your float valves are working OK, it shouldn't make any difference (for
all reasonable values of head of fluid). Until the fluid pressure is enough
to overcome the float valves, the float level will be unaffected. It's not
a linear thing.

 

Or he has a spare pair of carbs?

--
_______
..'_/_|_\_'. Ace (brucedotrogers a.t rochedotcom)
\`\ | /`/ GSX-R1000K3 (slightly broken, currently missing)
`\\ | //' BOTAFOT#3, SbS#2, UKRMMA#13, DFV#8, SKA#2, IBB#10
`\|/`
`

 

Testing while the tea was mashing confirms this.

 

The Bloo one and those from the red donor bike.

Very useful a donor bike is when you ride an SOB which turns out to have
been quite badly maintained by "professionals" some of whom have local
reputations for being good at their job. Cross threaded nut on the rear
wheel spindle is the latest one I have found. It leaves you with no
faith at all regarding the industry.

 

ding

I bought the red GS dirt cheap and loved it and despite it being a
shagged out heap of shite, decided to buy another.

I managed to get a good deal on the Bloo one because the bloke who sold
it to me thought he was ripping me off. He was wrong, it wasn't a
cracked crankcase, it was a badly fitted clutch cover gasket. Since
then it has been an ongoing process of putting the best bits onto one
bike.

 

Check the pilot/idle mixture. As these spend a lot of the time running on
the idle circuit, it needs to be right.

The aftermarket filter probably makes it run lean. Did you up the tickover?.

If so, reset the idle mixture screws to whatever they should be. 2 to 2.5
turns out or so. These may still be covered by those bloody anti-tamper
caps. Richen it slightly from stock.

Gunson colortunes are damn useful for this btw. Once the basic idle mixture
is right, set the tickover.

Next, raise the needles one notch. These bikes, certainly in the later years
of production run very lean. For the top end power, dyno time.

Krusty or Albrecht or whatever his current nym is posts the procedure over
in r.m.t fairly regularly.

HTH

 

No they don't, the idle circuit is only for the very low rev band.
Anything over nearly closed throttle and it is mains all the way
according to Mr Suzuki. Even up to there, there is sharing.

It does. This is a known feature of changing to a freer breathing
filter such as a K&N. It is one of the reasons why you change it in the
first place. That and the fact that the K&N is washable and reusable
for the lifetime of the bike which the factory ones aren't and work out
cheaper over that time.

I put it right if that is what you mean.

No they weren't. The carbs have been comprehensively had at because
someone "professional" buggered up the diaphragm spring in the LHS one
and bodged the rest of the carb settings to accommodate the subsequent
poor top end performance. They are now set to back factory standard.
Which if I recall right is 1 and a half just like most other carbs on
the planet.

I have lifted the needles two notches from stock (one in the case of the
LHS) and dropped the floats back to somewhere near factory recommended.
I am prepared to concede that I may have dropped the floats further in
an effort to "make sure" which is why I feel it may be running lean.

Good point. I haven't got one and it is a long way until my birthday.

It is nothing to do with the tickover but the speed at which the revs
drop from 3 or 4k or thereabouts with the motor on no load. I haven't
had it out on the road since I started faffing around so cannot tell
about real life performance.

They only run lean at the very top end of the rev range and only then
for the purists who want to race them flat out for extended periods of
time. For everyday use the factory settings are widely accepted by the
cognoscenti to be fine. Were it a water cooled bike it would not even
get a mention.

Ideally, assuming you have raised the needles the right amount, it
should have a slightly larger main jet to balance the extra air from the
new filter for mid revs but it is not considered essential even by The
Experts and right now I can't be arsed to change them and am prepared to
put up with the slightly poorer than perfect mid range performance until
I do. Especially as there does not seem to be any definitive size to
fit. Recommendations seem to be based mainly upon some very subjective
personal preference and experiment.

There are some lovely faqs on the GS500 lovers web site where I have got
most of my info from but this is well outside the range of what is
covered there. Nothing but success stories you see, no **** ever admits
what they did didn't work.

Not really but thanks anyway.

 

I can tell you the one thing both you, I and everybody else forgot to
mention:- Carb balance.

Whilst putting my tools away it just occurred to me that I haven't
checked that yet and I have changed things since it was last put right.

I know what I am doing tomorrow.

 

This is what I was going to suggest, it happened to mine. Also check the
choke cable and the cable routing.

 

How are you balancing them?

I've found that one carb being out can cause the whole plot to hang onto
the revs.

 

Vacuum gauges of course. Although with just two carbs it can be done by
ear with a bit of care and if I didn't have the gauges that is what I
would do.

I am amazed that I completely forgot about it. It's a simple rule, if
you mess with the carbs they will need rebalancing. Hey ho the real
life problems of creeping dementia.

 

Done all that and oiled the cables just in case. Trouble is though that
where I have been putting things right and changed the filter it has
altered the mixture, no doubt about it. The only doubt is whether it is
enough to give me issues.

Mind you having realised I haven't balanced the carbs I shall be looking
at that in full expectation it will solve it.