Starting problems

[carsounds_dan]

hi,
just tryed to start the ZXR400 to find it wouldnt start.
it cranks over, the ignitor unit has power and so does the fuel pump and coils so i'm guessing its not electrical.
after a while of cranking (3-5 seconds) i stop, and sometimes the exhaust (micron system) lets out a poof noise, asif its releasing some pressure through the exhaust system.
i dont want to continue cranking it over incase something is fecked and im making it worse..
any help on the matter would be great.

cheers
dan

[zxr_oli]

Mine is simliar, sometimes it wont start, with the occational poof.
Found it's somthing along the lines of gear sensor etc, so it wont start with the side stand down, or if i havn't pulled the clutch in.

[RedexRobB]

That 'poof' noise is a very faint backfire by the sounds of it. Sound slike its flooding slightly, check your plugs. I did exactly the same thing once i couldnt get the bugger started whatso ever, and when it did backfaire it did it loud and proper in my shed, ears were ringing for hours! Just whip the plugs out, give em a clean and re-set the gaps, should fire up instantly If not, try a new set of plugs

[masterofinsanity]

as RobB says replace the plugs.

[carsounds_dan]

kk, will do, what plugs do you recomend? im just looking to do a service over the winter, like a proper strip down and re-build before i get out on it in spring.
so what plugs would u recomend? and where to buy them from?
cheers
dan

[zimm]

im with it being the plugs too...

sometimes you can bring them back from the dead by removing them, cleaning them up, heating with a blowtorch and quickly chucking them back in.. but new plugs are a better bet.

CR9-EK, standard fitment plugs work fine*, dont be tempted to waste money on fancy iridium (or even extortionately priced surface discharge) plugs they wont make any difference.

*although they do suffer from the "i spark outside the engine when tested, but wont start your engine" problem if they've been flooded for any reason.. as you've just discovered

[carsounds_dan]

btw it bumps fine, makes all the usual rattles and shaking noises it does and runs alright after that.... if that helps?
im gunna strip the bike down next weekend and clean EVERYTHING lol, gotta work out a way of only letting the remote start on my alarm work when its in neutral now though.. yay

[zimm]

i'd still suspect the plugs, when bumping it the battery's power isnt being divided between the plugs and the starter, and a bump start generally turns the engine over faster than the starter motor ever would/could.

[zxr_oli]

I got new plugs yesturday.
All of the other plugs were about £3 each, and car ones were about £7/8 for 4.
But oh no, the plugs for the ZXR are £7.79 EACH, thats over 30 quid for 4 plugs! :smt013

[masterofinsanity]

i remember it well, should have looked on ebay, there is usually a chap selling 4 for a tenner.

[SplaTZXR400]

go to autolec if theres one near by, got 4 for £20 not as good as ebay but i prefer to have things then and there.

[carsounds_dan]

bump started it today due to it having a flat battery.
it didnt want to start, and when it did it ran lump as hell (almost asif its only on 3 cylinders).
when it did start it didnt want to rev at all, on a long blip that would usually have it round to 10-12k it only managed about 2-3k. so i let it idle a second before pinning the throttle, it went up to about 6k before i let off.
it then idled and i ran it up the drive to see how it pulled. it pulled lumpy as hell, when on anything other than full throttle.
i looked down and the rev needle was jumping from about 2k to 7k (i cant remember exactly). any idea what that could be?
i know on the yamahas the rev counter act as fault code readers...
o also, when i tryed to jump it later on i pushed the starter in and the rev counter fired round to about 6k.
sounds strange...

[RedexRobB]

I think thats a proper flat battery mate, member here had the same problem a while ago with the rev counter reading double the engine speed. Try putting it on charge overnight and see how it goes, if its still messing you about its probbaly time for a new battery! Will be worth giving those plugs a clean too, they are more then likely drenched in fuel now and well mucked up from it running badly.