Kawasaki gt 550 no spark

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Kawasaki gt 550 no spark

Hi all you happy chaps and chapesses out there, I'm new to forums and I hope you can help me. 

Bought a tatty,  just running GT 550 kwaker as but of a project for the winter. Have spent way more than it warrantied and was just about to go on its maiden voyage but it seems to have lost sparks to 1 and 4 pots and the rev counter has stopped working. Now when I bought it it was off on number 3 pot, got some new coils and all seemed fine, this was a few months back mind and I've had tank on and off dozens of times to fettle other jobs.

So the question is does anybody have an idea as to what has happed to my sparks ?

Now I hate electrics and have very little idea of what I'm looking at, have no workshop Manual but I do have a test meter so can stick my probs were directed.

Any help much appreciated.


First I would look at the earths on the bike, the main earth could well be corroded and is likely to cause intermittent and unrelated problems. Next I would check all the connectors, pull them apart and squirt some contact cleaner in and push them together a few times. Finally fill with silicone grease and connect. Another problem for a visual inspection is have a look at the wiring itself, it's not unknown on an older or high mileage bike for the plastic casing to go brittle and develop tiny cracks. All these may or may not show on a multimeter but I would use it anyway while you move things around. To check the coils take the plugs out and choose one with a known spark to test all the coils. If this makes no difference your carbs could need a strip and clean, also check the inlet rubbers and airbox for leaks. Good luck with it and when you've done all that repost please.

Hi. Thanks for that. I'm about halfway through all that and have found nothing so far. Will battle on and see what pops up. 

Adrians advice is good, but personally I like dry contacts not greased, if you have new coils fitted then I would suspect the low tension side of the faulty coil, check it's getting power and earth.

Have cranked the engine with a good known to work plug in each cap and I have a pretty healthy spark on all of them but the miss fire persists bellow @1500 rpm. All the plugs in the engine are new and I've swapped them about to double bluff it, still missing on nò 3. BUT it still feels like an electrical miss fire as when it does fire up its quite abrupt like a switch on and off ?!? I wouldn't expect a carb miss fire to chime in and out like that !! I'm going to squirt some "start ya bast@rd" into the airbox tomorrow to see if it will run at tickover on all four or it might do me a favour and burst into flames and blow up. I'll let you know which way it went. 

Have you swapped the coils and leads around? next bit in the process? see what happens, should run without easystart, was it lying unused a long time before you bought it?, If so could be lack of compression, rings are stuck in no 3, squirt some lube oil in no. 3 and leave overnight. Could be the plug or lead or cap if misfire transfers to another cylinder.

Coils and leads and caps are all new and swapped from side to side. As it's a wasted spark system, 2 and 3 off the same coil it's looking less and less an electrical issue. Never thought of compression as it runs well above 1500 rpm apart from the fact the revs don't drop quick enough when you shut the throttle to change gear.  Not known how long it had been stood before I got it but I'm pretty sure it spent most of its later years stood outside by the state of it.

Ah, explain a bit more what you mean by revs not dropping off, methinks this may just be a sticking throttle cable. Try soaking no 3 in oil overnight, then spin the engine over with the plug out just in case the oil doesn't get past the rings causing compression and damage.

Throttle cable is new ( no closing cable as i cant find one ) and it snaps shut if you let go so it's not the cable. The revs drop back very slowly if you blip the throttle so when your riding it and change up or down its still revving, makes for a very jerky gear change. Did soak no 3 over night, no difference lots of smoke. Any mileage in using some penetrating oil or lighter oil to soak over night ? Didn't use easy start yet as I'm a little distracted at the moment  doing a top end gasket swap on my wife's 76 Z400 twin, been throwing oil out so bad it was all over the side panels and her shins. Hope I've sorted it now, back together anyway.

Just reading this post back and realise I've mist an up date. Back at the electrical check stage I found the igniter box behind the headstock had some corrosion, rust on the connectors in the plug and two of the pins on the box were rusted part through and very wobbly. Got another box from a breaker next day delivery and that fixed the dead rev counter and sparks back to 3 BUT not the misfire on 3 at tick over. I know it's no 3 by touching the down pipes and it's cold at tick over. Hope that's filled in the gap, got a bit nonsensical.

Hi Paul, getting there slowly, I'm puzzled because revs dropping slowly and misfire in no.3 don't seem to go hand in hand? So lets go back to basics again on No. 3 only and get it working if we can. 1/. Ignition, is the spark a big fat blue one. 2/. Is fuel getting in? is the plug wet? (which it shouldn't be if getting a spark), no air leaks on induction, no blocked jets etc. 3/. If above check out, I know you've done them but check again (learnt through experience) then we have to suspect something mechanical. Try penetrating or lighter oil, but make sure you get most of it out before replacing plug. Theres another puzzle you mention lots of smoke, was that only after putting oil in no 3? or before? Is it only cold at tickover? rev her and see if pipes heat up.

Hi oldboy54, yes it is confusing and I haven't made a good job of explaining it, I've confused myself.  So as you say back to basics. 1. Good spark on all 4 cylinders now I've replaced the ignition box. I think I created this problem ( loss of sparks on 2 and 3 and dead rev counter ) by unplugging and plugging as many connections as I could find and not being thorough. The ignition box was only found the second time round after I'd been at it once and lost the sparks. 2. Now this one a little more complicated to explain. On tickover No 3 is not firing but as I open the throttle it fires up and runs fine, I can ride it and it's quite fit really for an old girl till the revs drop below @1500 No 3 dies again. This all makes it a pain to ride at junctions and slow traffic and tends to stall unless I keep blipping the throttle. The carbs have been stripped but looked well inside so not sonically cleaned, pilot screw set to 2.5 turns out, all diaframs looked good, I could find nothing obviously wrong with them so they went back on. Air leaks wise the manifold rubbers are sound not perrished the air box ones are a little hard so I removed the little springs and fitted slim screw clips, if it has a leak I don't know where. The smoke was just left over oil in No3 and is fine now. It is only cold at tickover as the pot comes to life above 1500 rpm. Originally I said "GT550 no spark" which looking back was misleading, I jumped to this conclusion without checking first and spent a load money on parts that probably weren't needed, my bad. I hope this has cleared the confusion cos it's certainly confused me. 

Hi Paul well almost 99% certain after your post that it's a carb problem and probably the pilot jet. Is it easy to swap carbs around? if so try on other cylinder and see if same problem. If not before stripping down see if you can get her to idle smoothly by adjusting the screw slowly at fast idle, pausing between adjustments, start at 4 turns out and wind in bit by bit. Failing that it's a strip down checking float height again and pilot jet and feeds not blocked, don't use wires use air or carb cleaner. After running properly recommend balancing the carbs. Oh and check the needle valve set correctly and needle not bent. Another thing just occurred to me, it's the screw on the bottom not the side for the pilot jet I think on your carbs.

Well carbs off again, float bowls off and pilot screws and jets out. Could see nothing wrong but blasted all the galleries out with brake cleaner and plumbers air canister, back together and onto the bike. Had set the pilot screws to 4 turns out and fired her up, HAY-PRESTO a stable but fast idle but if I blip the throttle the revs shoot up and drop back slowly.  So burn my hands and turn the pilot screws back in half turn increments. It's now a balancing act between a stable idle and slow rev drop. So I'm now at a point were the pilot screws are back to 2 turns out, the revs drop back acceptably quickly and No 3 is starting to miss. I had a thought and without taking the tank off fitted my vacuum gauges up, set the fuel to prime and fired up. I find that apart from all the carbs being badly out of balance No3 has next to no vacuum until it's past 2500 to 3000 rpm and even then bearly lifts the little rod ( it's a gunston tube style gauge ) to get a reading. So I don'tknow, either it's just the carbs wildly out of balance or there's something very wrong with No3. I'm getting seriously pissed with it now and you could see it on Gumtree shortly.

Yea you get like that don't you, but we're almost there don't give up, so back to logic and I think you've found the fault.  Carbs work on vacuum, the engine sucks, a vacuum is created, fuel released and mixed with air and bang, no vacuum no work. The pilot system is the pilot and air screw (and slide cut out )  At very low air flow through the carb (about to 1/8th throttle), the fuel is fed in front of the slide (engine side, high vacuum side) when there is not enough vacuum to pull fuel up through the needle jet (main jet) which is used after tickover. For tickover the airscrew adds air to the fuel to get the correct fuel ratio for idle and just off idle combustion, this is obviously not happening. So if you are absolutely certain all jets and passages are clean then we are not getting a vacuum, Take any air filters off, spin the engine and you should feel the same 'suck' on that one as the others. If you don't you have an air leak between engine and carb.

Just read your last post again and I think you didn't do the procedure correctly? first warm up the engine. Then on No 3 cylinder only turn the idle screw until you get a fast idle 1500-2000 rpm depending on engine. THEN play with the pilot screw as you described, you can hear when it sounds ok, then turn down the idle to normal revs. Theoretically you should do this for every cylinder before balancing the carbs, try it again first. I think a simple way of putting it is every carb has an ideal idling point for that cylinder, balancing them just means in the case of a four cylinder physically adjusting the linkage for all four to get them (sucking) evenly as opposed to individual adjustment. So at 4 turns you got a stable but fast idle, turn down the idle on no 3, then balance all four, usually 1&2, then 3&4 then bring them together. What you seem to have done was only adjust the airscrew.

 THE END. Well 54 I've reach the end of my tether and ability to progress this any further, it's time to move on. I know I'm gonna take a big hit on the money I've poured into it but that's a lesson learnt, make sure it runs properly before anything else. I understand all you said in the post above but applying it and making it work has beaten me. Thank you 54 for all the help and guidance, much appreciated.  Anybody out there want a project bike to do up or chop/café contact me through the forum, I'm open to offers. New Motard, vanhill lines, pads seals and pistons, coils caps and plugs, throttle and clutch cables, fork seals, oil and air filters, bla, bla, etc, etc.  Thankyou and goodnight.

Sorry for late reply Son I've been away, I know how you feel and I've been there many times myself, believe me. Let's not give up, suggest you leave it alone for at least a fortnight, think about it, and we'lll have another go Nil Carborundum Desperandum. In 2 weeks time come back and we'll have another go, it's at times like this I wish I could pop round and have a look, but we can't do that, we'll do it, we're nearly there.

Off to the North West 200 next Friday. See how I feel when I get back. 

If I'm not busy and get the chance I might go too, only major road race I've not been to, hope the weather is kind. Enjoy it relax and ask a few blokes there what they think is wrong, I'm pretty sure it's an induction leak. I'll think about it some more while you're gone.

Tragic, tragic news from NW 200 Paul, RIP Malachi, 20 years old, I watched him on BBC at Cookstown and thought what a great young talent. Then I watched from 1000 this morning on live coverage of NW, he was even shown in his drift car, a nice man and a talented rider. He chose to do what he did, but as a road race fan of many years I hope his death and Ryans serious crash are the last tragedies of this season. These riders are the bravest of the brave, my heartfelt sympathy to his family, friends and team.

Ya, very,very sad. We were about 150 mtrs further down the track when it happened, heard the crowd gasp. A great talent lost. Apart from that we had a fantastic time in great weather. Sadly had to go in the car as the wife's bike was not ready and she wouldn't sit on the back of my Street 675 R. The GT550 has been sacked off and traded in for a CB500X for my son, he's more than happy with it. The GT was gonna be his but he couldn't wait any longer and neither could I. Took a BIG kick in the nuts though, £500 is all I got.

Don't know about you but

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Pitty coz it was really useful.

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