Xj600s one wet plug misfire

[joriff]

First off i'd just like to say hi! I'm a new member and proud owner of my 95 Diversion 600s. I haven't passed my test yet, thats next month, but for now i'm looking to sort out the bike.

Problem has been told to me from the previous owner as follows:

Bike runs perfect, but after a few days the 3rd cylinder misfires. Take out the plug and its soaked. Its had new coils and leads but to no fix. fit a new plug and its fine for ages until the same thing happens. Any ideas?

Bike does not start with choke, it just splutters, not sure if this is related? Starts fine without choke. £150 spent on just the coils and leads being changed.

Many thanks and i look forward to peoples input.

Chris.

[beeblemaster]

Welcome to the club Chris.

I'm afraid I'm no mechanic, I'm learning bits and bobs though , so someone else will be along soon.

But have you done anything with the carbs? Checked/cleaned/balanced. Jets checked etc.

Have you tried new plugs or swapped them?

[sotirisp]

maybe it would be helpful to you if you check my older post there:

diversionclub.proboards74.com/index.cgi?board=600&action=display&thread=2686

[joriff]

(sir) I've not played about with the carbs yet, i'm thinking if someone knows a good place to start then i'll look there. Could it be just a build up of dirt/clogging?


EDIT

(sotirisp) Looks brilliant! i'll do a compression test too while i'm at it, but this weekend i'll work on the carbs. Got any pictures etc?

[General Gman]

If it won't start with the choke but starts happily without, I'd suspect it's running rich.
When you get the carbs off, check the float heights and see if the emulsion tubes are worn (if they're oval, the bike will run rich)

[darren]

Jun 17, 2008 21:50:19 GMT General Gman said:

If it won't start with the choke but starts happily without, I'd suspect it's running rich.
When you get the carbs off, check the float heights and see if the emulsion tubes are worn (if they're oval, the bike will run rich)

what he said, defo sounds carb related, not coils as one coil runs two pots

[bobh]

At a guess it could be a damaged float or sticky float valve or pivot on the cylinder that floods. I'd start there.

The carbs are easy enough to take off, but try to keep them as a unit as it's quite a job to balance them up again if you split them one from another. I'm fairly certain you can check these out without doing so.

Good luck - Bob

[joriff]

I taken the carb unit out, very orange looking with lots of rust particles in the float chambers, so cleaned them all. Everything else looks ok. floats move freely. I noticed some cracks on the large air inlet pipes from the air box so i'm going to replace those. The vaccum chambers looked fine, i did however forget to check the diaphram for breakages, would have probably noticed if anything was untoward. Think it was just the rust doing it? Any ideas where that came from? the tank maybe?

[sotirisp]

Joriff,

it may be the rust but generally any foreign particles in the carb circuit can do it.

I'd suggest a complete cleaning of the carbs (bath) first of all...
Especially since you found rust in the float bowls.

[joriff]

Done as suggested and cleaned out all jets etc with compressed air, shop was out of carb cleaner so cleaned as best i could without it. Oil is white! breather hoses have what looks like water in them, i can only imagine the previous owner only ever did short journeys, or the fuel has managed to get into the oil. Anyhow i'm doing an oil change today with filter replacement, also going to change the fuel filter incase rust is getting through from the tank.



I do however have a small problem........ i taken off all the hoses and dont know where they go now. oops.

[bobh]

Joriff,

Make sure you rod out the white gunge from the breather hoses, as if they are blocked it can cause rough running. A long test-tube brush is ideal, otherwise some electrical cable with rag wrapped round it will do.

Bob

[joriff]

Good advice bob, i'll do that! I'm gonna run some cheap oil through the engine for a couple of hundred miles to clear it out then replace it again, luckily it was only a little bit white around the hoses and filler cap. Oil when drained looked ok, just smelled old.

[CD]

I would suspect the choke plunger. They can stick open or shut and the rubber pad on the end can harden. Also check the choke cable is returning to off. Plungers fully down = off.

[joriff]

Put her all back together today and shes running great, slightly lumpy though I also have a rattle on idle from something, maybe left hand side of engine, goes away when clutch is pulled in.

[sotirisp]

so,

carburetor and hoses cleaning did the trick?

Or was also a problem with the choke?

P.S. I 'm not sure about the cause of the rattle in idle that you describe...Cam chain tensioner loose maybe?

[El Fuego]

Clutch rattle is quite common (from what I read here).

[CD]

Clutch pressure plate and release bearing can rattle until the lever is pulled in. There's also a mod for the oil pump drive to fix a rattling roll pin and lots more clutch stuff in the tech section.

[joriff]

Unsure what fixed it sotirisp, i cleaned the choke mechinism out, got rid of the rustyness from the carbs (most likely cause) and re-built them too, got a compressed air spray can and blew out all the jets. I emptied my fuel tank and replaced the fuel whilst also putting a small scratch on the paintwork! doh! Changed the oil and oil filter, there was a slight build up of white gunk in the breather pipe to the air filter housing (large one). I have yet to also replace the hose adapter that mounts onto the airbox as its damaged, this is 80p from mayhem motorcycles in chippenham wiltshire. I replaced the fuel filter too and whilst i was at it checked over all the hoses for damages or splits etc.


Sounds a lot but it was really easy and good fun to do too, didnt spend more than £20 in all i think, well worth doing once a year even if everything seems ok. I want to overhaul my brakes too but thats for another day.

[joriff]

Problem is back! aarrgghh! lol. I'm pretty sure now its running too rich and using the choke floods it. How can i adjust this?

[joriff]

As advised by haynes manual, tomorrow i am going to;

Remove the choke plunger and inspect needle
Check main jet needles for wear
Remove the pilot needle,inspect and re-install



I'll see if any of that helps!

[joriff]

Removed the plugs and it was soon obvious that i'd flooded it by using too much choke. Anyway, i sprayed compressed air into the choke plungers to clean them without removal and cleaned off the spark plugs. Its all working fine again now and i drove around for 30 mins with no problems.

The noise from the clutch was still apparent though, also it might be a bit rich as it smoked a little, not blue so shouldn't be burning oil, probably needs a good run as it hasn't gone over 20mph for 3 weeks!

[bostonboy]

clutch problem is an easy fix but it does mean empting the oil again
remove the cover to the clutch
remove presure plate
remove clutch plates
undo centre bolt (if i remember correctly)
remover clutch plate housing thingy-me-bob
on the back of that there is a cog that drives the oil pump
it will probably have free play
remove the circlip and the cog
you will see a small pin
this will need replacing with a 5.5mm piece of round steel bar (i used a the bottom end old drill bit)it wont fit straight away you will need to fettle a little i got out the files and angle grinder (only use angle grinder to thin out the bar)
get it all back together ensuring the cog is a REALLY TIGHT FIT
fill with oil and most of the rattle will be gone.

p.s while you there you could change the thrust bearing easy while you've got the clutch stripped.

hope this helps

if ive missed any thing sure it will be pointed out

cheers dan