Out on a gentle ride with chick on back today, I had to abort my ride after a serious misfire developed.
I managed to get back home and started to investigate, I quickly narrowed problem to number one cylinder . I changed plug , no different, I hung a spare plug onto number one lead this seems to have a good spark, starting to look serious. anybody got any tips on likely issues. seems a compression test is a next step ,starting to sweat!
try spraying lots of wd40 or similar around no 1 inlet manifold rubber as it may have cracked and you are drawing air i had similar problem its an easy cheap test --good luck
MY GRANDAD TOLD ME -WHAT DOESNT KILL YOU MAKES YOU STRONGER--EXCEPT FOR A BEAR THAT WILL DEFINATELY KILL YOU---
First, don't sweat. Compression testing and all that implies are a long way off! 
By all means check the intake stubs but even heavily cracked ones tend to stay air tight.
I'd start by taking off the plug cap, cutting 1cm off the lead and refit. You could have a poor contact between lead and cap, which you might have inadvertently 'made good' by your plug testing.
Consider also a fuel-related misfire. If the float needle seat O-rings start to leak, you can get a rich misfire on the affected carb.
What's the year and mileage of your steed? Ridden regularly? Any recent servicing or mods we should be aware of?
Mike
05-09-14, 08:21 PM
(This post was last modified: 06-09-14, 09:41 AM by bwizz.)
Thanks for imput guys , carb stubbs are sound, bike has done around 33000 . It is ridden infrequently . its an 05 ,around 10000 miles since I did the ivan mod+boots+ ignition advance+ air pump removal. always garaged. seemed a good spark whilst the spare plug was hung on the no1 lead " with engine running". reconnected still missing on no1. Not done any more yet
I have taken approx 1 cm from no 1 plug lead , also checked the no1 carb diaphram . that is ok . its goana be fiddly to get the float chamber of . is there anything else I should check before trying. do this ,faulty coils act up like this.? "engine clears above 3000 revs
Have a look at the plug cap itself, on mine I had a low running issue which was fine above 3k, the problem was the pin inside the cap had corroded, I have gone the individual coil route so no more plug leads on my bike.
Whats the individual coil route ? I did not know this was an option on a gen1. the plug cap looked ok but i'll double check
(16-09-14, 01:02 PM)bwizz link Wrote: Whats the individual coil route ? I did not know this was an option on a gen1. the plug cap looked ok but i'll double check It is a mod using stick coils off a honda cbr600, some kawasakis and suzukis, may the later FZ1 coils will fit depending on the resistance.
You might find this link helpful:
http://www.yamahafz1oa.com/forum/showthread.php?t=59207
The float needle seat O-ring problem requires carb removal to fix. Do all four carbs while you're at it.
http://www.yamahafz1oa.com/forum/showthr...ilure+mode
'Ridden infrequently' always makes me suspect the pilot jets.
You've probably thought this yourself but just in case. Good spark with spare plug but not when plug lead reconnected to the plug in the head ... have you changed those two plugs over?
Yes Mike I swapped plug and the fault stayed on no1. Gonna get a compression test at a local bike dealer then if thats ok I'll check the carbs. looks possible to get a float bowl of the no 1 cylinder at a pinch ? engine does not smell rich though despite the missfire
It's not the float bowl access that's the issue, it's the O-ring which seals the float needle seat and you can only work on that with the carbs on the bench.
Besides, if one has failed then the others won't be far behind. I suggest you plan on changing all four O-rings as a precaution, even if the fault turns out to be something different.
I checked supplied links thanks Mike ,Neither really fit my case .I took the bike to a local dealer for a compression test . no1's ok so thats a relief. also got the plug end cap checked for resistance, bike does not smell rich and even ticks over fairly well. I don't get a fuel feeling about this issue,On the short ride to the dealers it felt like maybe there is another cyclinder coming and going. so maybe a dicky coil or associated wiring. A local breaker has a coil so wortha a try
Getting to the point where i'm stumped. I got a coil from a breaker from a kawasaki but similar.Fitted it, Engine started up nicely and ran cleanly whilst in nuetral . once round the block and its misfiring on more than one . I took out the number one plug that was previously black now its clean. started again cleanly round the block ditto. seams like some sort of ht breakdown .
In the interim I went to the local garage to get some petrol, bike would not re start. call out RAC , he check sparks , nothing dead, Then just as mysteriously restarted
.This has happened twice before so the issue may not be related. but now back home bike starts but still the missfire issue. seems I need to get a Fazer coil, then that is one unknown quantity
out of the equation. any more ideas guys before I book it in somewhere
Have you checked all the earth connections and the white connector block, left side, under the tank?
Also, give the ignition switch and the Run switch a thorough flushing with WD-40.
Both these are known causes of electrical issues on the Gen 1 and while they might not seem obviously linked to your symptoms, best eliminate them first before buying new coils and so on
I did not know of a white block under tank being an issue. I repeatedly flicked the kill switch and the side stand . the RAC man wagged everything in sight under seat and behind side pannels
He certainly removed and refitted the cdi unit plug. But It seemed to restart with non of these being at issue. I'll give it a go with WD when the stress level has gone down a bit. Good stuff WD ,used it for years. Thanks for imput Mike.
Calmer today , I took tank of and pulled apart the white block and another black one. lagged everything in sight with WD "thanks Mike"!. Bike seems to start better. So hopefully cracked the sudden death syndrome. I need to change the coil though, as the first issue was on no 1 cylinder , its better now but still not 100%. What does the white terminal block connect up?
Thanks all, great forum!
The issue - and cure - with the white terminal connector is covered here:
http://www.yamahafz1oa.com/eskortsdefect...ment.shtml
OK ta interesting
Had another short ride tonight , started of fine running nicely on all four. came back with with cylinders coming and going, I've not taken a plug out yet, but now there is more than one cylinder playing up. seems a ht issue.
My dad had the same issue on a ride out. Turned out 1 of the leads had a tear in it. Changed all 4 problems solved. Hills Breakers still have 1 set for the gen1 thou as well.
here. £36.
http://www.hills-bikes.co.uk/yamaha-fzs-...49053.html
Ta but I've a new coil and coming with leads for 2 cyclinders £20 new .E bay ! If that don't fix it I'm out of ideas.
brian
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