Kawasaki gpz1000rx .

[ladreborn]

Guys , i have a intermitant problem on this bike , driving me nuts , At times and for no reason at all it will drop a cylinder and run on 3 , i have being taking it to a bike shop and leaving it there for them to look at , this morning same happened , yet , when they went to check it out , it fired up on 4 !!!!! this is the 5th time it has happened , any thoughts ?
cheers

[miSTa]

I'm no expert but I'll offer a few thoughts...same cylinder everytime? How healthy is the spark on each plug? Coils maybe, swap coils - does the problem stay on the same cylinder or follow the coil? HT leads and plugs? Igniter on the way out?

I take it the problem has just started? Did you change anything before it started?

[ladreborn]

Howdy , bike has new plugs , new leads , new battery , its pointing to coil hey ? do iridium plugs make a huge difference ?, i guess before u throw them in , u,ve got to know that coils etc are good .

[FROSTY]

Try swapping the coils left to right see what happens

[roadracingoldfart]

Guys , i have a intermitant problem on this bike , driving me nuts , At times and for no reason at all it will drop a cylinder and run on 3 , i have being taking it to a bike shop and leaving it there for them to look at , this morning same happened , yet , when they went to check it out , it fired up on 4 !!!!! this is the 5th time it has happened , any thoughts ?
cheers


When you encounter your "intermitent "problem what do you do or what happens to make it run on all 4 again. Do you let it cool off , change the fuel tap position etc ?? Is it also the same cylinder that goes down ??
Anything to allow us to make a more informed diagnosis.

[ladreborn]

On , one occasion a few weeks back , i,d been for a 250k run on sunday , found it harder to start on the monday morning then it started , running like a dog on 3 , rode to bike shop , they looked at it next morning , Fired up on 4 , then this week , from cold start , fired up on 4 , few seconds later dropped one , rode to bike shop , left it there , when they got there 30mins later , started it , well , back on 4 !!!!! there was a little fouling on num 4 plug , but damn all he said , he couldn,t remember , but thought last time he looked it was num 2 , do they run off same coil ? 2 and 4 ?
cheers

[T.W.R]

On , one occasion a few weeks back , i,d been for a 250k run on sunday , found it harder to start on the monday morning then it started , running like a dog on 3 , rode to bike shop , they looked at it next morning , Fired up on 4 , then this week , from cold start , fired up on 4 , few seconds later dropped one , rode to bike shop , left it there , when they got there 30mins later , started it , well , back on 4 !!!!! there was a little fouling on num 4 plug , but damn all he said , he couldn,t remember , but thought last time he looked it was num 2 , do they run off same coil ? 2 and 4 ?
cheers

One coil for cyl #1 & #4, the other coil for cyl #2 & #3 :yes:

There is the possibility that it isn't electrical at all and could be fuel related & most likely moisture in the carbs, it only takes one small droplet of water around the jets or emulsion tube to upset things :yes:

[ladreborn]

So how would it only effect say one or 2 cylinders ? in this case #2 and 4 ? -------------------------emulsion tubes ? were are these ?:sick:

[JimO]

hi toysky i dont think its fuel im not a expert but would say it would have to be electrical

[ladreborn]

u think they are worth a try ? , poointing to coils /coil / or ignitor hey ?

[JimO]

beats me, i bought a new bike because i dont have the time or knowledge to tinker with it

[Max Preload]

Iridium plugs don't fire better... they just last longer.

First order of business is to establish exactly which cylinder is dropping. You can do this a number of ways, but the most reliable and simple method is by measuring the exhaust headers with a non-contact temperature sensor. They're not cheap, but perhaps you can borrow one. You could also use a timing light to establish if the cylinder going down is electrical - when it's down but the HT is still firing it could point to fuel. But the trouble with that is the spark could be shorting to earth somewhere other than the plug earthing electrode which will still indicate firing.

What are the supressor caps like? Have you measured their resistance?

Also, if it was a coil, you'd get 2 cylinders dropping, not just one.

[T.W.R]

So how would it only effect say one or 2 cylinders ? in this case #2 and 4 ? -------------------------emulsion tubes ? were are these ?:sick:

Right lets do a process of elimination:

You have: 1)New Plugs, 2) New HT Leads, 3) New Battery

You have an intermittent firing problem on one maybe two cylinders

The Ignition coils, IC igniter unit, & pick-up coil haven't been touched.

If the pick-coil or the IC igniter unit fail it's usually a total fail :yes:
If a Ignition coil fails 2cylinders will drop simultaneously.

Simple check for the coils is to check each plug is sparking individually (if the leads aren't numbered then number them 1st) remove all the caps from the plugs. With a sparkplug you know is good place it in a cap (start at #1 thru to #4) earth it on the cylinder block & spin the motor over on the starter. If the system is working the plug will spark on it's firing stroke (hopefully a light blueish spark) & repeat across the other caps.

From what you say about the times when it drops a cylinder it doesn't lead to a problem of major proportions because it isn't breaking down under load, it's been doing when the bike is sitting running.

The emulsion tube (needle jet holder) sits in the heart of the carb, the main jet screws into it's base and the Jet needle runs through it.

Any bits of contamination in the carb bowl get drawn through the jets (either the primary or main jets) any moisture in there also becomes a droplet of water and will block jets partially or completely causing misfires or complete failure of a cylinder to fire. As the problem is happening when the bike is started then there is a good chance the primary jets are fouled.

With the age of the bike there is a high chance of contamination in the carbs and if there isn't a in-line filter in the fuel line from the tank then there is a higher chance of contamination.

[ladreborn]

Well theres alot of food for thought there , the strangest thing is it fixes itself after 10-20 minutes lol , then may not return for a week or 3 . but i,ll look at all your points , i,ve just being out there with crc , cleaning elect connects , filling up battery levels etc they were up and down abit , a couple by a inch ,? oh yeah i do have a in line filter

[ladreborn]

Is there a good product i can toss in tank with gas , to perhaps unblock , clean in carbs ? as they were off , a month or 2 ago , and i was told they were ok but ?

[JimO]

Well theres alot of food for thought there , the strangest thing is it fixes itself after 10-20 minutes lol , then may not return for a week or 3 . but i,ll look at all your points , i,ve just being out there with crc , cleaning elect connects , filling up battery levels etc they were up and down abit , a couple by a inch ,?

new battery should not be loosing fluid

[Taz]

GPZ900's sometimes did this after being parked in the rain or washed when on the side stand. Water could find it's way into the r/h sparkplug tunnel and cause a short but once warm the moisture would evaporate and the bike would run fine. Just a thought.... A smear of silicone between the cap and the tappet cover can fix this problem.

[ladreborn]

Just being for a ride , higher speed stuff , not 50kph , and guess what , yep , started to misfire etc , the horse power its got , lets it be hideen at higher speeds with revs up , but it was there , i,ve got it in garage , i,ll look at plugs . i for sometime thought it was only happening riding to work , 50kph ,

[Max Preload]

GPZ900's sometimes did this after being parked in the rain or washed when on the side stand. Water could find it's way into the r/h sparkplug tunnel and cause a short but once warm the moisture would evaporate and the bike would run fine. Just a thought.... A smear of silicone between the cap and the tappet cover can fix this problem.

I'm pretty sure toysky garages his GPz1000RX. He's had the plugs out - I'm sure he would have noticed water in the suppressor caps.

But the point is nonetheless valid - many 4 cylinder DOHC engines suffer this problem with water (particularly with aftermarket suppressor caps) if left on the sidestand in the rain. Even oil can do it - I've had that happen to me. My GPz600R many years ago also did it.

[Max Preload]

New battery... and you're adding water to it?

Have you checked the output of the alternator? How many volts across the battery terminals at 4000rpm?

[ladreborn]

Idonn,t have the gear to measure this , could this be part of prob then ?

[ladreborn]

yes , bike is garaged , but if at work , it sits outside ,

[Max Preload]

yes , bike is garaged , but if at work , it sits outside ,

Are the supressor caps the originals i.e. is there a molded piece that fits snuggly over the spark plug tube over the rocker cover to prevent the ingress of water?

[Max Preload]

Idonn,t have the gear to measure this , could this be part of prob then ?

It's possible, but not likely. However, as said before, you shouldn't need to add water to a battery very often, and certainly not a new one.

[JimO]

my Z1R had aftermarket supresser caps that caused it to fart about if used for around town riding and this went away when they were replaced

[BM-GS]

If I recall (the memory gets fuzzy) Kawas of this vintage were prone to carb-icing. If it only happens at low-revs, but it clears at full-throttle, when the engine and weather are cold (especially cold & damp) you'll probably have this problem.

There were assorted fixes to do with routing coolant around the carbs (to warm the intake charge, stop the icing & reduce power, so check that these are there and functioning.

I had a Yamaha RD350 which did that - it didn't half make winter roundabouts entertaining... Running fine, cough, splutter, slow, more gas...both pots at 6000 rpm, ice, big truck...!

[roadracingoldfart]

I still lean towards a fuel problem . Either dirt or water. As its winter we have a problem with dew forming inside the tank from the cold mornings even in a garage and as we aslo all know , water aint no good as a fuel.
My first plan of attack would be to drain the tank and carbs and refill with fresh gas to see if it still continues. While the tank is empty get a good look into it however you can to look for any signs of rust grit etc. Check the fuel you drain out carefully (empty it into a clean catch container) for water and if you do find it you will have to have a really good clean out of the fuel system including the filter. Any water will look like a small puddle of clear globules at the bottom as water is heavier than fuel. Its amazing how many bikes rust out the tank on the left hand side because of the side stand and when i was working on bikes for a living it was a real headache, especially on farm bikes and such.
I hope this helps you out.
Cheers Paul.

[Max Preload]

Its amazing how many bikes rust out the tank on the left hand side because of the side stand and when i was working on bikes for a living it was a real headache, especially on farm bikes and such.

Yeah - my NS400R rusted a hole in the tank in that manner - I saw the rust stain begin just after I bought it (of course).

[T.W.R]

A new battery shouldn't loose a substantial amount of acid quickly. The type of battery the RX has is filled at the shop prior to a sale. And to add, even if the battery levels are low once the engine is running it is of little consequence and wont have an effect on an intermittent misfire.

If the carbs have been off recently, was the problem occurring before they were removed & checked or after? And were they set-up properly when they were refitted?

A quick fix for moisture in the fuel tank is a cup of Meths, but this wont get rid of any droplets in the carb itself. They'll have to be removed and cleaned out properly.

[ladreborn]

Well it played up after my higher speed run yesterday , and in the past it has come right by itself , sitting overnite or even sitting for 30minutes last week , -------------------this time it has not . running like a hairy mutt , on 3 , hmmmmm ., i,ll check out some of your thoughts .

[Max Preload]

Well it played up after my higher speed run yesterday , and in the past it has come right by itself , sitting overnite or even sitting for 30minutes last week , -------------------this time it has not . running like a hairy mutt , on 3 , hmmmmm ., i,ll check out some of your thoughts .

So it's been sitting out in some considerable rain more recently?

[ladreborn]

Being working on bike this noon , took off tank etc , looked at plugs , NUMBER 4 OILED/PEROLED UP all others fine , petrol in airbox , a wee puddle , prob 2mil deep by 50 mil , this was on right of bike , same as num 4 cyclinder , hmmmmmmmmmm , what does this tell u /us ? the plugs are NGK D8EA says in manual for USA and ITALY running . are these not hot enough ? i do not ride at 200kph , or rev past 6k has potential to 250 plus and rev to 9k , do i need hotter plugs ?

[ladreborn]

No water found ,

[roadracingoldfart]

Hmmmmm, Im thinking !!!!!:shit:






.

[ladreborn]

Bike sorted , now need to see for how long , had some good advice from a guy in wellington , New plugs , cleaned airfilter , new fuel filter , cleaned carb choke slides , all free now , fingers crossed ,

thanx to all posters

[delusionz]

Always go with the iridium plugs, they are far superior to standard plugs and even platinum plugs. Make sure to cross reference your standard plug to the appropriate iridium plug. If you ride for long periods of time, take the option of a colder rating if available. They do indeed produce a better spark, also last alot longer, stay cleaner, etc. It's all in the 2mm difference and the quality of the metal in the tip.

Use of iridium will result in easier cold starting, improved throttle response and may serve to remedy (but not cure) your misfiring cylinder.

[T.I.E]

but bloody strange. keep us updated.

[ladreborn]

That part of my problem , was the fact that even a bike mechanic down here was not replacing plug after finding it was oiled up , just a wipe with a rag , then sticking same plug back in , i the other nite put new plug in , my filter , air , is so clean , and a new fuel filter , so far so good , oh and cleaned carb chock slides , fingers crossed , i,ll thru some meths in tank to remove moisture ,

[Max Preload]

That part of my problem , was the fact that even a bike mechanic down here was not replacing plug after finding it was oiled up , just a wipe with a rag , then sticking same plug back in , i the other nite put new plug in , my filter , air , is so clean , and a new fuel filter , so far so good , oh and cleaned carb chock slides , fingers crossed , i,ll thru some meths in tank to remove moisture ,

That's not remedying the cause of the plug fouling in the first place.

Earlier this year I had a problem with oil down the plug tube which manifested itself first as a misfire once on the way back from the Battle of the Streets in Paeroa, and 2 weeks later suddenly became running on 3 cylinders at anything over 1/4 throttle. The rocker cover seal plug tube seal was leakng oil down into the plug tube and covering the suppressor cap - the tube was almost full. The plug was fouled but only because the spark was shorting to the plug tube through the oil. It took repeated applications of degreaser up the suppressor cap to clean all the oil out and get the cleaned plug firing again.

Basically, if the plug is fouling it's fouling for a reason. It might be the water down the plug hole. You never did answer whether the original suppressor caps are still fitted, or if they've been replaced with aftermarket ones without a seal on the top.

[ladreborn]

It sure looks to me like they are originals , they have the rubber seals at top of tappet cover , what i did thou , just because i could , was wrap insulation tape around each , rubber , from top to sparkplug tip , to ensure theres no sparks /power leaking out to no were .

[Max Preload]

Don't take the name "insulation tape" as meaning it's good high voltage insulation. It works ok as a stop gap on low voltage exposed conductors but won't do squat in this scenario except make the leads and supressor caps all sticky for the next time you have to dry them out...

[ladreborn]

so far still ok , --------------- but heres a little something else !!!! . After i got it sorted few days ago , i ran across article on how to start bike lol , well , because i thought , the lesser choke i gave it in morning , with a little trottle i would minimize the chance of my old prob acuring , WELL -------------now i,m giving it half to 3 quarter choke , NO THROTTLE and it jumps in to, life , and as i said so far so good , let it idle for 1 minute , choke off , and away i go .------------------could this of been some of mty problem ????????????????

[JimO]

could be ...my last bike (komnsukme 750) wouldnt start cold with any throttle but only full choke and once warmed up was fine, but if you used throttle it wouldnt start for ages and then once started would miss and fart about

[ladreborn]

And all is still good !!! perhaps i was the cause of my own problems ?