Thanks Craig. I will check all this stuff out. SWMBO's out on the raz...I mean out for a meal with some chums this evening so it would seem to be a good time to make a start once the kids are tucked up in bed.
Will keep you informed.
Thanks both!
DP
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Sticking exhaust valve/burnt out seat can give similar symptoms - lumpy at idle, but apparently clear itself further up the rev range.
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OK, made a start this evening - just started to get fed up with it so downed tools and left it for tonight. Here's what I found.
Started the bike and ran it with the fuel tap off until it stopped. Tonight it started on three cylinders, and ran on three until the engine cut out. The misfire was distinctly audible on idle whic it wasn't yesterday. Heard it smooth out and pop onto four for half a second or so once or twice but that was it.
All hoses and pipes associated with the carbs seem to be in good nick with no visible damage. The inlet manifold / boots are also in good nick. All clips and fasteners were tight, as were the HT leads and LT connectors. I will do a coil resistance test while I have the coils off.
Took the plugs out - all a nice light brown colour with light soot deposits consistent with just being sat on choke. No individual plug significantly different to the other three. Plug gaps are correct and the plugs themselves in good condition.
Took the carbs off and set about dismantling the first one. The diaphragm is in perfect condition, and the inside of the float bowl looks clean enough to eat from. Float moves freely, and no sign of varnish or gum deposits anywhere. Similarly the jets are shining brass. Haven't taken them out and cleaned them yet, but looking at the overall condition of this first carb (and assuming the others are all the same), I have a horrible feeling I'm barking up the wrong tree. I will check the jets for blockages and give everyting a good squirt of carb cleaner and a thorough dry anyway as I've come this far.
ifithelps - thank you. I guess if this doesn't pinpoint anything, a compression test is next. I'm really hoping it's not a major mechanical problem like that.
Thanks again all.
DP
Edited by DP on 07/07/2009 at 22:10
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When were the valve clearances last checked DP? COuld be one has just closed up and is causing low comp on that cylinder, which WILL chime in at higher rpm.
A compression check will tell for sure. Is it screw & locknut or bucket & shim adjustment?
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Hi Craig,
I checked them about 500 miles before it was laid up, and they were all within spec. They're shims unfortunately - cams have to come out to access the things.
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D.P. How old are the HT Leads ? That would be a cheap start before the Bike gets pulled apart. Can you swap them with known good ones ?Also are you on a wasted spark system with the Kawasaki ? Or do you have four Coils-They can suffer from damp !
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What was the fix on this one DP ? Most people use these forums to find their problem, and a fix to it. Most problems are quite common to 'that' vehicle. So the next Kawasaki with your problem wont have to go to a thread. Just a search ! Cheers mickyh7
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Gentlemen,
Sorry for the lack of update. It's been a chaotic couple of weeks with a big insurance job that's been coming on the house suddenly kicking off in full swing, and having to move out for a few days while it happened. Anyway, that's by the by.
I've stripped, cleaned and reassembled the carbs. They weren't that bad, although there was some black goop in the pilot jet on no 3 which took some time to blast through with carb cleaner. All diaphragms are OK, needles look OK (they're quite new anyway), but there was a layer of greenish yellow goop around the slide area which cleaned off OK. They look pristine now, and are reassembled, ready to fit.
I also found no1 HT lead wasn't quite as snug a fit on the plug as it could have been (it pulled off a bit too easily).
I'm hoping one of these was the cause. I will hopefully have time to reassemble the bike this weekend and will report the outcome.
Cheers
DP
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Quick update.
Reassembled everything (minus the airbox), drained the fuel tank, and stuck in a gallon of pump fresh Unleaded. After a bit of cranking, she fired up. Still on three.
I was pressed for time, but I confirmed the following:
There is compression on all four cylinders (turned the engine by hand and no detectable difference in effort required to overcome the compression on each pot).
Each plug has a spark that's visible in daylight (removed plugs, connected them to their own leads, earthed to frame and cranked)
What I have noticed is that by lifting the slides manually on each carb and letting them fall back to rest position, there is a noticeable difference on no 4 compared to nos 1-3. There is less effort required to lift the slide, and it drops quicker, without the damping effect and "sucking noise" of the other three. I checked the diaphragm again, and I can see no defects or damage. Not sure why this should be the case.
I am still thinking fuel, given that none of the plugs are sooted up or wet, but I'm getting stumped now. Next stage is to disconnect each plug in turn with the engine running and work out which pot is actually not firing. If it's no4, I'm definitely suspecting a carb defect of some description.
Any suggestions advice still welcome.
Cheers
DP
Edited by DP on 22/07/2009 at 10:11
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Plugs may look OK But under load they may be finished. (starting up every week and revved on choke over the winter kills plugs )New plugs are a a good try anyway !Can you borrow a set of known good Carbs to try. Failing that you might find it quicker to cut your losses and get it into a workshop for a diagnostic. You might get it sorted before the Sunshine goes away. Keep us informed please. Regards Mick.
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Sorry about the lack of update on this one everyone, but I have just not had a second to even look at this until today.
Mick - I think you've hit the nail on the head with the plugs. I tracked the misfire to cylinder no 2 and took all the plugs out while I was pratting around with other stuff. Put it all back together. Misfire was now on no 3.
Swapped no2 and no3 plugs and the misfire moved back to no 2
New set of CR9Es will be fitted in the next couple of days. HOPEFULLY that's it. Fingers crossed.
Cheers
DP
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Glad your getting to the bottom of this one. I was raised with 2 strokes,and road raced them for years. Plugs were always a major problem. Nearly always seemed to be OK until the engine was under load. A nice cheap fix. Remember to run your engine until there is no fuel left in the Carbs. this winter. And never start the bike up weekly/monthly during its lay-up. Just trickle charge the Battery. Good Luck. Mick.
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Four new NGK spark plugs installed tonight, and pleased to report it's running (with the airbox off which always makes it a bit lumpy) on four again! Bogs a bit on throttle, but I'm hoping that's just where the engine's cold and the intake system is in bits and various intake plumbing is disconnected.
Coils both refitted and HT leads routed tidily, airbox and its associated spaghetti is all reassembled and fixed. There must be 20 miles of pipework crammed in there what with the crankcase ventilation system and various vacuum and breather pipes. Just got to refit the tank and seat, and refit the side panels tomorrow night and we'll know. Going to take the opportunity to change the rather manky looking main fuel hose while the tank's off too - a piece is cut to fit and waiting.
Also took the opportunity to cut the HT leads back a few mill and screw the plug caps into fresh cable, as they weren't the most secure fit (although were functioning OK). Much better now in any case.
I've always been pretty good with draining the carbs down, which makes me even more annoyed that for some reason this time I didn't.
Cheers
DP
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Good news DP and I hope it's sorted. It's worth trimming the HT leads as you did because the cores do get corroded over time.
I don't know what type of plugs the Kwak uses but I've always had excellent results with NGK EVX platinums.
My Suzi triple 2-stroke loves these -- they never, ever seem to wear, foul up, or need cleaning / regapping despite the harsh operating environment and dense, oily mixtures they are required to ignite :-D The current set has been in place for 4 years.
The cheapest place I've found for these is www.sparkplugs.co.uk, works out about a fiver per plug.
Cheaper in the long run for me as strokers tend to eat ordinary plugs in no time.
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Intrestingly I have a very simular issue with my 96 zzr600, which also has been layed up for many years. I wire brushed all the plugs and adjusted the gap. It started first time with a bit of choke and warmed up perfectly. First mile or so she ran perfect but then started to misfire at anything below 4K revs, dropping to firing on three, over next few miles I arrived home hardly able to keep the bike from stalling. I've just ordered a new set of plugs as suggested, see how that goes, keep you posted, and let me know how you get on.
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First proper ride tonight, and I'm pleased to report it's fixed. Back on four and flying again. I will never assume visually perfect spark plugs are in good working order again.
So happy, I'm going to ride her to work tomorrow! :-)
Thanks everyone for your input and help!
Cheers
DP
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Yup - 25 mile run into work this morning, and didn't skip a beat. It's definitely fixed. A joy to be back on 2 wheels and saved 15 minutes on a 25 mile run. Can't be bad.
Rob - let me know if the new sparks solved your issue.
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What can I say, the new plugs have cleared up the misfire, the bike is smooth goes like a train again. I'm little anoyed with myself with the solution being so simple. I have wasted days of time recleaning the carbs, checking the float heights. I even bought a spare set of carbs off ebay convinced they were the cause (before reading this post) Anyway I'm happy the bike is running sweet, and thankyou for your help
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As Mr Dunlop was heard to say - 'I'm yer man' (When it comes to plugs).
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