Dobbin Posted January 23, 2010 Share Posted January 23, 2010 Hiya all, Been having a read through a load of posts to try and find some info, but thought itd be worth posting to see if anyone has any ideas.. Story is: I Have a 1991 XJ 600 (pre divvy), its been stood for a few weeks with all the crap weather weve been having, so went to fire it up yesterday without any joy. fully charged the battery (its only a couple of months old anyway, but flattened it trying to start for too long), blast of easy start in the airbox and vrooooooom, sure enough it starts..... After about ten minutes or so, it cut out, no stuttering or spluttering, just died like flicking the kill switch. Lights still on etc. Tried to fire it back up and it would turn but not fire. So back in for a brew and head scratch, after about ten minutes or so, tried it again, fired up straight away, minute or two later, died again. same symptoms. Now electrics aint my strong point, and thats what im dreading it is, so i tried a few bits and bobs to try and fix it but am getting the same result... things i have tried are: recharging the battery completely again, new spark plugs cleaning the battery terminals and leads with sandpaper, removing the digital ignitor and cleaning its terminals, checked all the fuses and cleaned terminals, checked to see if the coil packs are overheating. trying to run with no electrics on (ie lights) ran without petrol cap on incase of airlock or something of that nature i even tried a spark test (though i might have cocked that up as never done it before) where i took a lead at a time off and tried with one of the old plugs, but didnt seem to get a spark from any of them (this was done immediately after it cut out and wouldnt start)which being there are 2 coil packs, im surpised im not getting a spark from anything (hence the might not be doing it right lol) so general fault is, it will start, it will run for a few minutes, then die, and it wont start again for about ten minutes or so. Now i am assuming this is electrical, but for all i know it could be something stupid like an airlock, i just assumed since it died without sputtering its unlikely to be fuel related. Anyways, sorry about the long winded post, just wanted to be thorough, as im out of ideas short of breaking out the multimeter and checking absolutely everything (and even then no idea what im looking for ) If anyone has had anything similar, or even some suggestions as to what i can try/test etc, itd be very much appreciate. Mike. Link to comment Share on other sites More sharing options...
mike1949 Posted January 23, 2010 Share Posted January 23, 2010 It really does sound like a fuel problem to me.(I'm no expert though) With electrical problems it either will or won't start, with fuel problems, ie flooding, if you leave it for a few minutes it could possibly start. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 23, 2010 Moderator Share Posted January 23, 2010 Could be a dirty fuel filter wherever it is on that bike, thus the engine runs but the carbs have only a trickle flow of fuel feed. The carbs run dry, the engine stops, the trickle flow re-fills the carbs, and so on and so on Link to comment Share on other sites More sharing options...
Dobbin Posted January 24, 2010 Author Share Posted January 24, 2010 thanks for the suggestions chaps , ive been out this morning, pulled the tank and tap off, given the filters a clean (wernt in bad nick to be honest) and cleaned the fuel lines as best i can and still getting the same result. Pulled a plug (which are only two days old) and they're black and sooty, cleaned them up and getting no spark again on all four cylinders. Leave it for a while again and it will fire up for a few minutes again and then die. Whip the plugs out again and sure enough theyre black as hell again. ive bled some fuel out of the float bowls and theres a bit of sandy red shite in it so its entirely possible that the carbs are the cause. The only thing i cant understand is if it is a fuel issue, how would it cause the plugs to stop sparking... Good ol' Mr Haynes shows pretty pictures of plugs in this state and it point to either fuel/air mixture (which makes sense if its burning wrong) OR a faulty ignition system (which again makes sense. So im still no closer to figuring it out.... it could either be carbs full of shite even though it hasnt stood for too long, or it could be dodgy electrics in the ignition... think the next step is to attack it with a multi meter and check voltages before and after it dies before i look at pulling the carbs off as i aint too comftorble pulling them apart, i can guarantee ill have something left over when i put them back together again Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 24, 2010 Moderator Share Posted January 24, 2010 Can you turn the fuel to 'Off' or is it vacuum operated? If you can turn it off then start the bike turn fuel off and just when it starts to die turn it on. Repeat this process just to get her warmed up if it works. also a spray of WD40 around the HT caps and leads may help. Link to comment Share on other sites More sharing options...
Dobbin Posted January 24, 2010 Author Share Posted January 24, 2010 Its a vacuum carb unfortunately, but i suppose its possible that theres something dodgy in the vacuum system, it might be causing it to flood as theres always fuel in the float bowls so i doubt its starvation, and flooding would explain why it takes a while to settle and start again. well im fed and watered so gonna go back our and hit it with a hammer until it works if i figure out what it is ill let ya know incase anyone else has this problem in future, but all suggestions/advice is always welcome Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 24, 2010 Moderator Share Posted January 24, 2010 Its a vacuum carb unfortunately, but i suppose its possible that theres something dodgy in the vacuum system, it might be causing it to flood as theres always fuel in the float bowls so i doubt its starvation, and flooding would explain why it takes a while to settle and start again. well im fed and watered so gonna go back our and hit it with a hammer until it works if i figure out what it is ill let ya know incase anyone else has this problem in future, but all suggestions/advice is always welcome No, with a vacuum tap there will always be fuel in the float bowls unless the tank runs dry. But with the engine not running the fuel supply should stop, you can test its function by 1 pull off the fuel pipe from the carb and place in a suitable container 2 Pull off the vacuum pipe from the manifold 3 suck on the vacuum pipe 4 you will see fuel delivery only when suction applied Link to comment Share on other sites More sharing options...
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