giocast

as someone else said, correct Karma for Zarco after Rea 'incident'

i'm too late!! - was going to suggest you try 'Easy start' to try and prove if it's fuel related. If i'm stumped it's an easy test to do to save time (if you're careful). To add to all the other suggestions it could be a small amount of water in the carb float bowls. Tends to happen when bike hasn't been used for some time. Another idea - did the engine oil you drained out smell of petrol? I won't bother to explain why i'm asking now you've taken it in - just a thought.

Tango has covered every angle - it's definitely one of those! Going by what you said sounds like it could be over-advanced ignition and you did the right thing to stop it as soon as you heard something unusual, if only as a precaution. If you remove the spark plug and study it, it could give you some clues as to what was happening although ten minutes might not have been enough to leave any tell-tale signs.

also, I remember that those engines are sensitive to the choke position so only use full choke when it's stone cold and experiment with the position until it will idle (unless something else wrong with basic settings/condition). Also, the idle speed on warm up can make the engine peter out once on the road and fully warmed up, so be aware that you need to turn it off when appropriate.

Reading plugs is a bit of a black art at the best of times but from what I can see from your pictures you have nothing to worry about. Let's put it another way, you certainly aren't running on the rich side, at the top end anyway.

although expensive, that's one advantage of the Dynojet filter (carb) packages as they supply larger main jets and even air correctors sometimes to ensure mixture is correct. Fitting those cone type 'performance' air filters to a 2 stroke without re-jetting spells death to most engines.

glad to hear it - do you mean the tapping is in the manifold or the fuel tap?

wouldn't do that myself - them vacuum petrol cocks cause enough trouble on their own if left standing.

You need to find a convenient 'hole' in one of the inlet ports between carb and engine - hopefully there will be a plugged hole in the form of a screw in all four inlets that would normally be used for checking/balancing carburretors - you might need to obtain a threaded hollow junction tube (usually brass) if it doesn't come with the 'kit' (matching the thread of course). You can then use this to attach your flexible vacuum supply tube.

Wish I was closer - just had a Google Earth reminder of Cat&Fiddle/matlock - what great roads. I will have to get up there sometime.

just to (possibly) set the cat among the pidgeons here - there is a common misconception that an officially fitted restrictor kit manufactured by a professional body complete with certificate is the only legal method of restricting a motorbike recognised in the UK.. it isn't and there is at least one company churning out what boils down to glorified penny washers at extortionate prices that, let's just say aren't quick to step forward and tell you this..

As has been said above, not totally practical on a 750 but not unheard of. I remember a kit for a Ducati 916. Your kit, if it exists would almost certainly consist of 'washers' in your inlet ports/rubbers or exhausts (nearly always the inlets) and/or a hand throttle limiter. Your best bet would be to ask on a Kawasaki dedicated forum (I guess you have already). I used to be on the largest one in the UK (can find a link if necessary) and they are (or certainly were) a friendly bunch - one member sent me a GPZ500 indicator in the post for free - he wouldn't even accept the postage.

I shouldn't ask, but did you change plugs for same as before - i.e. correct ones? You could pull one out just to check how it's burning since filter change.

plus one - and don't go pushing hard 'til you change it back just to be on the safe side. K&N will often suggest what size jet you might need (if at all) when changing to their filters. You might even see a small rise in running temp in worst scenario.

what bike do you have? (might even be injected for all I know!) if it's got carbs and you can get to them, most have a provision for draining the float chamber(s) (if you can get to the bottom of them ). Obviously if you're not confident then don't do it - but what comes out can give you a clue what's happening. There could be rust and there could be water (and it only takes a few droplets to cause havoc at idle) or they might be clear. If it's a four cylinder and the first one you try is clear then you might not decide to persevere with the others. Don't overtighten the drain plug as they can strip if you're not careful.

There are many symptoms as a result of gummed up carbs Don, from not wanting to idle/erratic idle (can be primary or idle mixture circuit or water in the float bowl(s)) to a midrange or high range stumble/misfire or hesitation (which can be partially blocked main jet). Has bike stood for a bit - say in damp conditions or have you run out of fuel recently?

so - none of you fancied it then?.. you didn't miss much tbh

a shameless bump for anyone whose missed this.. (tomorrow, Sunday 2nd)

If weather like today (all blue sky) then this will be a cracker - it's free and hopefully the racetrack will be jammed pack with motorbikes. Bear in mind this is a 'breakfast' event so will be wound up around midday (i.e. - get there early!)