|
|
What's wrong with it then?
|
My SO GPZ550, that is.
In low gears it runs well up to about 8000 rpm, and then misfires at
8500 rpm, won't go above that.
In top gear, it runs fine up to 60mph (5500 rpm), and then stutters and
slows as if it was running out of fuel, picks up again after a few
seconds when the throttle is closed. With patience, it can be coaxed up
to 70.
|
Holed carb diaphragms. But I see you say you've checked 'em. Hm.
|
\______________________________________
\
You know, until today I didn't know there was a 'g' in that word.
|
Coils, then.
|
'new' ones on the way[2]. Took it out one more time, up to 90mph, and
every time it stuttered, there was an electrical "tickatickatickaticka"
from under the tank[1]. Paying really close attention to the revs when
|
Hmm. Could be a HT lead breaking down/leaking under load too, then.
|
It is going to rain in the next couple of days. A good time for an easy
diagnosis.
|
|
it stuttered showed them to be 7-8k in every gear.
[1] top tip, when trying to work out where on ones motorcycle a noise
is coming from while travelling at high speed, keep one eye on the
road, I (briefly) forgot that the 329(M) curved so much...
[2] Prices for *new* ones being ?80 for all 4 cylinders.
|
I have a pair of Dyna coils here that are up for grabs.
|
Go on then, assuming they're the right sort, how much?
|
They are for Bandit 1200/early Gixers, and the price is 40 quid the
pair plus p+p, with leads but not sure how good the leads are. They
are a pair of coils with twin leads on each.
|
Apparently I need Dyna Part# 21-7412 (2.2Ohm).
But I'm going to do a darsy, and say I don't know whether or not I want
them at the moment - if you've still got them at the weekend, let me
know.
|
|
|
|
|
|
Running the bike on main/reserve/prime makes no difference, fuel pours
out of the tank on prime.
It hasn't been used in the last few years, and when I got it, it was
only firing on two cylinders. I replaced the duff spark plug (3
cylinders) and took the carbs apart and removed the gunk from the
main/needle jets (4 cylinders). I've changed the oil and filter, and
after a disagreement with the air filter, I put 4 individual (one per
carb) K&N filters on.
|
Have you jetted to suit these ?
Sounds like main jets are to small
|
They might be, but it feels to severe to by just running a bit lean.
If the electrics turn out not to be the problem, I might go up a jet
size (or more likely, get a second hand set and drill them out) and see.
|
|
The carb rubbers are fine, there's petrol in the float bowls, the
slides move up and down like they are meant to.
|
When you say carb rubbers do you mean the inlet manifolds or the
diaphragms?
|
The diaphragms, although both are fine.
|
Both can cause trouble and you need to stretch the rubber a bit to see
if there's any sign of perishing rather than just give it a quick
visual.
|
Yeah, checked them properly.
|
|
I'm about to put the old air filter assembly back on for another run,
but after that I'm out of ideas.
|
All the problems I had with the GSX1100F (fouling plugs, running on 3,
etc) where all caused by duff plug leads. I had the bike to three
separate garages before "I" finally found the problem.
|
|
Has yours got float valve filters? Might be worth checking them and/or any
|
I'll add them to the list, cheers.
|
rubber o-rings/bungs you might find in there. Also, fuel filter(s).
14043 and, possibly, 16017 if that's an o-ring. And 92055A & B.
Or a coil breaking down as Mr.Auvache says, although it sounds more to do
with the carbs to me.
|
Or something else in the ignition - leads, plugs.
As throttle opening and revs rise more voltage is
needed to fire the plugs (roughly) and there is
also correspondingly less time to generate the voltage.
I have no idea if this is safe on a modern bike (or a person
attached to a modern bike) but a decent test of the
voltage generating capacity is to see how big an air gap
the spark will jump. IIRC 1cm or more will I guess be OKish
but I would expect more, say 2cm.
It is safe on an old contacts and coil rig.
My money is on fuel too.
If SO rides like a woman, fouled plugs?
|
|
|
|