N1NJA Posted June 21, 2011 Posted June 21, 2011 O.k. so I decided rather than taking the car to work I would use the bike this week. On my way to work yesterday the bike ran out of fuel so I had to switch to the reserve deciding to fill up on my way home from work later that day. Took the bike to Sainsbury's and got home. Later in the day I started the bike up to park it up at the front of the house. The bike ran really rough and cut out the first time round, the second it ran just long enough to put it on our front. I dismissed the issue to being a cold start. This morning I came to start the bike and it had to turn over loads before it would start and then was running really rough (Missing). I had to sit there for 15 minutes till the engine warmed before it would tickover but it was still running like a diesel.My first thoughts were that I had pulled some crap through into the carbs when the bike ran out of fuel so whilst at work I've purchased some fuel addative to clean out the fuel lines and jets on the carbs. I ran the bike a good 30 miles back to the garage where I store my bike but the problem didn't get any better, if anything it seemed to get worse.I've now stripped the seat, fairing and fuel tank off. I decided to start the bike without the fuel tank on and 'bingo' the bike seemed to run absolutely fine. So my question is do you think it could be fuel starvation maybe a dodgy fuel tap or could I have done something else by removing the tank to make it run?I must say I'm really annoyed at the guy I bought it from, it's supposed to have just been serviced but underneath the fuel tank is filthy and the air filter was black as night. I'm taking the spark plugs out at the weekend gawd knows what I'm going to find there! Oh and the bikes a 2001 ZX6R... Quote
eastanglianbiker Posted June 21, 2011 Posted June 21, 2011 are you sure the breather hole in the cap isnt blocked as that will make it run rough or got a trapped fuel pipe or vacumm pipe that r uns from inlet rubber in front of carb onto fuel tap or could be internals of fuel tap have worn away and blocked hole that fuel runs through Quote
N1NJA Posted June 21, 2011 Author Posted June 21, 2011 As far as I could see the breather pipes looked ok although I think I'll remove them all at the weekend to give them a clean up. There was only one pipe on the fuel tap, should there me more? I did find a breather pipe that had been purposely blocked up which looked as though it was supposed to go to the air box but there was no where for it to fit to. Quote
Bogof Posted June 21, 2011 Posted June 21, 2011 As far as I could see the breather pipes looked ok although I think I'll remove them all at the weekend to give them a clean up. There was only one pipe on the fuel tap, should there me more? I did find a breather pipe that had been purposely blocked up which looked as though it was supposed to go to the air box but there was no where for it to fit to. Did you unblock it? Quote
N1NJA Posted June 21, 2011 Author Posted June 21, 2011 No, I figured it was a vac pipe of some sort and it was obviously blocked for a reason reason. Quote
megawatt Posted June 21, 2011 Posted June 21, 2011 If it started and ran ok with the tank off, then you may have had a blocked breather. If I were you I would remove the tank, drain fuel into a clear container and look for crud and water in it. Remove fuel tap and clean it. Remove carbs and check bowls for water and crud. Give em a thorough clean with brake cleaner. When you replace , make sure breathers are clear and not pinched, vacuum connector runs from engine inlet stub to fuel tap diaphragm and is not split or pinched. The blocked breather you found should connect to the air box and sometimes deposits oil vapour from the engine onto the air filter. Unblock it and direct into a small container to check engine is not over ptessurising or rings are passing. Good luck, Alan. Quote
N1NJA Posted June 22, 2011 Author Posted June 22, 2011 If it started and ran ok with the tank off, then you may have had a blocked breather. If I were you I would remove the tank, drain fuel into a clear container and look for crud and water in it. Remove fuel tap and clean it. Remove carbs and check bowls for water and crud. Give em a thorough clean with brake cleaner. When you replace , make sure breathers are clear and not pinched, vacuum connector runs from engine inlet stub to fuel tap diaphragm and is not split or pinched. The blocked breather you found should connect to the air box and sometimes deposits oil vapour from the engine onto the air filter. Unblock it and direct into a small container to check engine is not over ptessurising or rings are passing. Good luck, Alan. Thanks for the advice, could you explain 'rings passing' & 'ptessurising' please. Thanks again. Quote
megawatt Posted June 22, 2011 Posted June 22, 2011 The engine breather is there to depressurise the engine on the outside of the cylinders and pistons. If a piston ring is passing , it can pressurise the engine and blow combustion products and oil mist into the airbox. If you unblock the tube and direct it into a container, run the bike for a few rides and check the container. If a lot of oily crud in there, you may have a piston ring that is worn or broken. Unblock the tube, run the engine and feel how much pressure by putting your thumb over end of tube? Quote
Colin the Bear Posted June 22, 2011 Posted June 22, 2011 With a worn piston ring or bore the combustion blows past the piston and into the sump. A simple test for this is to remove the oil filler cap and run the engine. smoke and allsorts will blow out if you have a fault there..If the bike runs fine with the tank off it's more likely to be a fueling problem. Tank breather is suspect. open filler and listen for hiss of inrushing air. Some have a pinhole in the filler cap that can become blocked. If you have picked up some water in the fuel there should be a drain access to the float chamber to drain it away.It's a common urban myth about dirt coming through from the bottom of the tank. Most bikes are gravity fed. The most common problems after running dry are air locks in the pipework and gum/tar drying out and bunging the works up.Do the simple things first. Quote
N1NJA Posted June 22, 2011 Author Posted June 22, 2011 Thanks for the help guys its much appreciated. Looks like I'm going to have a fun weekend Quote
Tango Posted June 22, 2011 Posted June 22, 2011 Like others have suggested...I'd try and run it with the tank on but the filler cap open. That'll tell you if it's a tank breather issue or clogged cap breather.Also check that there's no wiring getting trapped by the tank when it's on. While the tanks off maybe give it a clean and then run round with a bit of ACF50 particularly on any electrical connections around there.Good Luck,Bob Quote
N1NJA Posted July 4, 2011 Author Posted July 4, 2011 Stripped the bike down and had a good check/look around. The spark plugs were knackered so I've put in a new set. I've check all the air feeds and vacume pipes but can't see any problem with those. The Spark plugs were quite wet and one was quite black. On putting the bike back together it sempt allot better although was still lumpy in the low rev ranges upto about 3000 revs.I've run the bike over the weekend and today and the problem has slowly returned to how it was before. I suspect the bike is over fueling and wetting the plugs. Looks like the carbs may need adjusting.Please correct me if I'm wrong or you have any other suggestions?... Quote
Bob R1 Posted July 4, 2011 Posted July 4, 2011 Check that the choke isn,t sticking on,also that the air filter isn,t filthy,would cause it to run rich good luck Quote
N1NJA Posted July 17, 2011 Author Posted July 17, 2011 Well after 3 weekends of checking, cleaning and re-setting i've finally found my problem. There's a cut off valve switch on the fuel pump. This is burnt out which means the fuel pump is continually pouring fuel into the carbs. New switch ordered and bike booked in for carbs setting and balancing and i'm back on the road Quote
Tango Posted July 17, 2011 Posted July 17, 2011 Glad you found the problem N1NJA.....interesting one!!!Good Luck and thanks for letting us know what you found.....stored away for future reference. Quote
N1NJA Posted July 17, 2011 Author Posted July 17, 2011 Thanks, and yes Ive read far too many threads over the last 3 weeks that have the same problem I had but just end with no result Quote
Tango Posted July 17, 2011 Posted July 17, 2011 Yeah...it'd be nice if people find a fix to post it up on the forum. We all learn from it and it adds to the collective reference knowledge pool!! Quote
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