Hi guys Have a weird one with my '91 3LN. It started maybe 3 months ago. I was riding down the Tulla Fwy and put on the juice to overtake a car, went around a bend and then started losing power. You'd rev and get no power. So I pulled over and it conked out....and wouldn't start. I called a mate to come and pick me up and then kicked it in the guts after maybe...5 minutes. It started as if nothing had happened. Truely weird. So I rode it home and it decided to die again - same story. I'm a regular rider - nearly every day - and since then it has maybe happened 3 times. It'll die, come right, die, come right, then when I next use it - no problems. More recently though it's been more rough to rev - you flick your wrist and you often get a delayed reaction - but she idles fine and otherwise works okay. Occasionally she'll pause for a second too when you drop down and flick the throttle open. But it's not consistent. I also noticed it has started to make a bit of a pop noise out the muffler when I am changing down and decellarating towards lights, etc, at about maybe 9000rpm. It never used to do that until after the conking out business. ANy ideas? I had the carbys cleaned and balanced recently, and a general service, fuel lines are good, and anyway even if it was the carbs/fuel lines the fact that it only happens periodically, not always, kind of kills that idea. Another idea I had was maybe something in the electrical system? Thanks Steve
could be a fueling problem - check the fuel tank cap vent is not blocked, your fuel filter is ok and you don't have crud in the fuel tank. Did it happen when you were low on fuel (or on reserve)? do you have a fuel pump? Could be electrical - is the battery ok and the charging system working (you can check that with a multimeter). Oh ****, i just gave you questions, not answers. Damn it. i don't think the popping noise is a serious problem - my fzr did it and always ran fine - its usually just unburnt fuel exploding in the exhaust can near an air leak - and personally i used to dig it.
From the information you've given i'm also of the opinion it's a fuelling issue. That said, i used to have a quirky issue similar to that which turned out to be a corroded spark lead! I know you've said you lose power but what sort of loss of power? Is it like you've switched the fuel tap to off and it's a gradual drop in power or is it sudden like someone has hit your kill switch? Also the popping in the exuast note, is it a rich popping like a wet burble or a dry popping? The way your described it led me to believe it was a dry popping noise which points to leaning out; and again a fuelling issue.
No fuel filter apart from a little bit of gauze at the entrance to the carbs. Might check the fuel tank cap vent over the weekend. Seems to pop more when it's low on fuel/on reserve... No fuel pump either. Doesn't seem to ever have had one but there's a suspicious looking mount where one probably should be on the frame. Battery's fine, just recently recharged it after letting it go flat (left the key in it, whoops)! The popping is kinda cool, kinda weird. Its like a little 'chonk...chonk' noise. I cant describe it any better than that...bu tit certainly sounds like it's a bit buggered! lol
I might also check all the sparky leads, I recently replaced the spark plugs so I wonder if one is loose. The loss of power is more like switching the fuel tap off - it's gradual but quick enough that I better get over to the shoulder. It can kinda stay at the same revs with not much load, but keeps wanting to conk out.
Mine had the same thing happen two or three times in a week or two, running out of juice, you can keep the revs at a certain point but it just wants to die and if you let go of the throttle it gets lower and you can't make em' climb. This started to occur more frequently and the popping sound "popped up", my bike was always running rich but the popping sound was a sign that it was running real rich (130KM out of a full tank). If you hold the revs at 5K you can hear it popping. like interruptions in the usually smooth exhaust note. I opened up the carbs, cleaned out all the crap but I can't seem to make it run leaner no matter what, somethings ****** up inside the carbs and the screws don't do ****. BTW: Cleaning out carbs made the bike a lot smoother, it also gave me a noticeable power boost so that might be all you need to do (If it's not running rich).
Thanks FZR250Guy - you sound like you're having the same symtoms as me. I took it a while back to a guy called Yuki at Southern Cross Sports who did a good tune, balanced and cleaned out the carbs and said it is indeed running rich. I get about 160km/tank before reserve so it's not too bad I guess. He improved it somewhat. I might try the 5k rev thing and see if mine sounds the same. Probably will! So I dont think it's the float bowls needing cleaning as they weren't cleaned that long ago, but I might check the fuel lines and make sure the hole in the top of the tank ain't gunked up.
