xj600 (fj) 92 still wont start, think ive sussed it!!

managed to drop my xj600 pre diversion (uk model, think they were called the FJ over the water) engined rat on its right hand side whilst jacking the back up, since then its been a pain in the a**.

Ive taken the carbs off, cleaned the float bowls, drilled the pilot jets out a little bit as it was a touch lean and i suspected the cold weather wasnt helping her, cleaned the air jets in the intake side of the carbs and checked the slides work. HAVEN'T checked float needles or height (will do that tomorrow)

Checked the valve clearances, one is 0.05mm under, one or 2 are 0.05 over tolerance, shouldn't be too big a problem. checked camchain tensioner and timing, dimples line up with the t mark as they should. I cranked it over without the carbs and put my hands on the inlet stubs, 1 2 and 3 sucked my hand in, 4 blew back a little bit.

Changed the battery for a 12v 18ah one, fitted new starter motor brushes, cranks over at a fantastic rate of speed and has a healthy spark on all 4 leads, all 4 plugs have been cleaned and gapped, sparking well.


onto the symptoms:

after i dropped it, it took a bit longer to start than before, i thought nothing of it and went off for a ride, turned it off and it wouldn't start without a jump start. next time it needed me to put my hands over the carb mouths as an additional choke to get it pulling fuel in and running.

did all the work written above, it started in the workshop with minimal carb covering so i put it outside, kitted up and went to ride home, wouldn't start without the jump pack and wouldn't idle below 3krpm, wouldn't rev over 5.5k without cracking and refusing to rev higher. cut down to just 1+4 working then shortly after it cut out and the battery was too flat to start, jumped it, rode 1.5 miles home, turned it off outside my garden to unlock the gate and it had a battery too flat to start again.


Has anyone got any ideas to get my reliable old beast reliable again? used to fire up pretty much on the button.


Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it do

well in my expert opinion (not) id say your charging system isnt working. cause running bad does nothing to effect the charging system, if the motor is turning its charging. as for your other prob, id pull the carbs apart and check the float needles, i bet that rubber tip fell off or something like that. am i wrong or does cold weather help a lean mixture?

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

You seem to have at least two faults.

Charge the battery fully and start the bike. Check the voltage at the battery terminals . It should be about 12.5v at idle increasing (Slowly) to 14.5 at about 3000 rpm. If it isn't then you have a charging problem. Your bike does not have alternator brushes, it is the permanent magnet type.

You really need a manual and should follow the tests. This seems to be a problem on a lot of XJ's (Mine was the same). If you havn't got a Haynes manual I can pm you and suggest where you might find one.

It is possible the plug has come out of the regulator when the bike fell over. This would account for the charging suddenly being a problem. If the battery is going flat, electronic ignition will start to give trouble as the voltage falls. You could also check the connections under the R/H cover to the TCI (Electronic ignition) for corrosion.

With regard to the lean running, it certainly sounds fuel/ carb related. Make sure you have a good flow coming out of the fuel tap.

Next it looks like the carbs. Thoroughly clean them, including the emulsion tubes and every other hole you can find!

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

cheers guys, ive been proving with the multimeter a minute ago and with a battery at 12.5v (not fully charged according to my charger, i'll repeat in the morning when its good) I have 12.4v at the TCI livewire, this goes down to 8.9v when cranking, also the 2 wires with there own 4 pin connector on the TCI have 0.7v each.

Does this sound healthy guys?


Oh by the way markie, i havent got a manual, cant find one anywere


Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

if the charging system isn't working and the battery is weak. that could also be a reason why you having a hard time starting it. it's called weak spark.

make sure the charging system is kosher. that will hopefully fix all your problems. (with any luck)

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

Once you have the manual you can check out the connections. I don't think 8.9v is enough for the electronic ignition. My bike had a weak battery and would crank but not fire.

I resorted to bump starting it.

I know from memory that two of the wires to the tci are from the ignition pickup and another two from the tci fire the coils.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

well after gettign the manual (cheers chap) and making sure the battery is charged, im getting 12.9v at the TCI with no load, 9v when i push the starter button. resistance across the pickup is within spec, Im starting to suspect its not electrical to be honest, im going to have the carbs apart again today and see how that goes.

Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

what's the voltage at your battery with the key off. with the key on. and with the motor cranking.

12.9 is pretty high. take into account the voltage drop throughout the wiring. the battery probably reads a little higher. then add to the fact you're down to 9 when you crank it. which means your battery is reading is also reading 9 or slightly above. that's not enough to provide spark.

the tci needs battery voltage to work effectively. 12volts.

i'd still be looking at the battery. either the battery isn't working or the starter is pulling down too much.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

its got a spark, ive got a spark gap meter and its jumping 15mm.

before the drop, when i had my nackered starter with brushes almost back to the brush holder and a 9ah second hand battery it still provided enough grunt to spark and run beautifully, with the 18ah battery and new starter brushes its cranking and sparking very healthily.

surely if the spark was good enough to run before i put a new battery and starter on it then it would be good enough to go now?

carb bowls have fuel in them, no water in there, the 4 micro filters on the needles are clear.

Im lost as to why this wont start

Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

are you saying your spark plug gap is 15mm. cuz that equates to .59 and that's too high. should be .28

now if your using one of them plug gap meters that has a handle to adjust the gap. you should have spark up to 1/2 inch gap i beleive is the spec. if it stops at 15mm gap then you've got a problem. (probably the coils). or electrical somewhere not providing full battery voltage to the coils.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

There's a pretty foolproof Test!

Shoot some Starting Fluid into the Fresh Air Intake Port.

Try it.

If it Pops or runs for a second ...
It's FUEL related.

Nothing:
Probably Spark related.

If you feed Start Fluid to it and it runs, ...
Something Is way-off with Fuel Delivery.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

Hi guys, snowwy, its one of those plug gap scissor items, unfortunatley it only goes up to 15mm so i cant test much further, by doing my usual plug test (screwdriver in the cap, hold screwdriver and see if it hurts) I can tell its got the best spark on any bike ive ever had or done that test on.

Rick, tried that last night and it coughs but i wouldnt say runs at all.

A few specs for you guys:

Compression:

Cyl 1: 140 dry, 150 wet
Cyl 2: 140 dry, 145 wet
Cyl 3: 130 dry, 150 wet
Cyl 4: 145 dry, 155 wet

Valve clearances:
Cyl 1: inlet .15, exhaust .20
Cyl 2: inlet .20, exhaust .25
Cyl 3: inlet .15, exhaust .15
Cyl 4: inlet .20, exhaust .10


I assume that its valve clearances from that, exhaust 2 and inlets 2 and 4 obviously out of spec wont help, ive borrowed a micrometer from the workshop and will be attempting to juggle shims until I get good clearances over the next few days.

Do you suggest changing any others? a few are near the top of tolerance, are they worth changing or leaving for now?



Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

valves might have to be adjust but you've got the compression to make it run anyways. even if it is uneven.

you could use a screwdriver to ground the spark that way. only pull the screwdriver UP TO 1/2 inch away from the motor. (i'll have to find the exact spec).

a good spark will run like a champ with a shot of starter fluid. for a breif second. you could actually make the thing run by constantly squirting start fluid. without any fuel being supplied. if all your getting is a cough i'd still say weak spark.

maybe push start the thing for kicks and giggles to see what happens

i have a 74 ford pick up. i use starting fluid on it till it runs on it's own. beats burning the starter motor up waiting for gas to flow into the carbs again. the truck gets used maybe 4 times a year MAX. i dont' do a constant squirt though. i use a pulsating squirt. just enough to make the engine run without racing or dieing. usually takes about 10 seconds before the carburetor kicks in on it's own.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

did you say you DRILLED out the slow running jets ! if so i would be looking to replace them as they are whats used to initially start it up so they could be flooding it now you have opened them up.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

drilled with precision jet drills, they were lean as hell and not letting me idle so i drilled them out to the next size, i believe its 0.05mm bigger than it was before in its lean condition, I highly doubt flooding anyway as it was playing up before i drilled the jets out.



Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

I know this may seem a little simple (but I have seen it done) in all your checks did you have the coils disconnected from harness? It is possible to swap connecters (orange usually goes to #1/4) and grey to #2/3) but check your manual since it has good compression and spark (15mm gap is good) maybe timing issue from swapped coil wires at harness?

Good luck

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

Something else I thought I would just throw out there if this is the same as US FJ 600 (1984?) it does have brushes for gen. another thing that manuals say on static tests of stator is check ohms from each white wire to each other however you should also check from white wires to ground (never seen this in the service manuals but they do get grounded) doesn't sound like this has anything to do with running issue but I have never seen it mentioned in the forum before ( but I am new so if it has been sorry)

Again
Good Luck

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

coils are plugged in correctly, colour coded connectors so its pretty hard to get wrong lol.

One thing I did spot whilst working on the valves though, the pickup for the ignition is actually cracked, Im in the process of sourcing a new one even though this one tests correctly for resistance according to the manual.

I believe its the same as the FJ, im not 100% sure to be honest but im pretty sure the charging system is working now, it used to play up but i found a bad wire on the reg rec and fixed that today so hopefully that will sort that.

In other news, out of the 4 valves that were out, ive straight swapped one, im taking 2 into the workshop tomorrow to surface grind down to size and then ive just got to source a 275 and I can put it all back together (hopefully with a new pickup if i can find one soon) and see if it will actually start.


It seems like im working on everything at once, i never normally take a bike off the road for a winter rebuild but this one seems to be a good time to overhaul everything whilst its dead lol

Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

So the coils are right, but the pickup coil is cracked? Something else that can effect timing while you have the pickup cover off you might want to take the timing plate off that is attached to the crank some of these have a locating pin that could be sheared or even missing. If you don't have the tool (usually an allen wrench) check to see if timing mark (you used for checking valves or timing cam) lines up when #1 piston is at TDC. Not sure of your exact results were with starting fluid but if just coughed backfired etc. then I would look at this if more or less ran (even rough) then diregard. I have no experience with UK models so these are just educated guesses.

Good luck

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

If you're referring to shims in this statement, DON'T! They're not hardened all the way through; grind through the hardened surface and you're asking for trouble.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

bigfitz is right they are only surfaced hardened, I think yours uses the 26H type so you should be able to get them. By the way I think the model you have is the XJ 600 (Seca 2) not what we used to call FJ 600 completely different bikes. Sorry I may be the only one that was confused my title says it all (lol)

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

The Euro XJ600 was imported until 1992 before it was replaced by the SecaII. There are some small differences to the FJ - notably the alternator on post '89 models was permanent magnet.

Crikey - I almost sound like I know what I'm talking about!!!

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

not wanting to call you bluff fitz, I fully believe theyre surface hardened but I did it before when I got the engine in april to get them within spec and now 18 thousand miles later 4 are 0.05 out of spec so i doubt it affects them too much.

I agree the proper way of doing it would be replacement but im not even in the financial position to buy a 5 pounds shim at the moment, hence the grinding them in.

Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

is the spark plug supposed to be 15mm OR .28 inches.

15mm is twice the gap of .28 inches

15mm is equivalent to .59 inches

isn't .28 about the average spec for most motorcycles? given there low secondary voltage output.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

Sparkplug gap usually .028-.032 inches. I think he was talking about air gap with adjustable spark tester spec on alot of the older bikes was 6mm minimum so 15mm should be good.

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

plug gap is set correctly, 15mm is the air gap as oldtexasguy says


Cheers
John

 

Re: xj600 (fj) 92 refuses to start, runs terribly when it does

So today I put a new ignitition pickup (complete left hand cover actually, with the stator in the middle aswell) on it, it still wont start.

Valve shims are back in and within spec, fuel in the carbs, good spark, still wont start



anyone else got any more ideas cause im completley out, at this rate i'll be doing an engine swap on it for something more reliable. all this after a little fall off the sidestand in my back garden? no thanks.


Cheers
John

 

Re: xj600 (fj) 92 still wont start, loosing faith with this

have you tryed to push start it? im not talking down a hill, im saying call a buddy with a car or truck and hold on to it and get to about 30 and dump the clutch in 2nd gear. if it can start, it should start then. if not try it again, ive had to do this to clear out carbs a few times.

 

Re: xj600 (fj) 92 still wont start, loosing faith with this

Try not to panic!

Are the plugs getting wet after you have tried to start the bike? This is a good indication that the fuel is actually being drawn in through the carbs.

If so, try the bump starting method so you have maximum voltage for the ignition.

Did you try the easy start method?

Lastly - have you got K & n type filters on the bike - which dont help cv carbs!?

 

Re: xj600 (fj) 92 still wont start, loosing faith with this

I'm not really familar with the UK model but it sounds like from your description that the pickup is in the cover and it has a permanent mag rotor (as one of the guys over there said). When you were squirting the starter fluid did it try to run or just backfire and cough? If it did just backfire and cough and it has the raised area (reluctor) on the outside of the rotor that acts as the pickup area and the timing marks are on the rotor try aligning the T mark (this should be TDC) on the rotor then check thru the #1 (left) sparkplug hole with something and see if the piston is all the way at the top if it is not the rotor key may be sheared causing the ignition timing to be off. If it runs at all with the starting fluid then ignition timing is not likley off. I also assume you rechecked your spark after pickup etc were replaced. Again sorry I don't know much about UK models.

 

Re: xj600 (fj) 92 still wont start, loosing faith with this

Well I got it running!!!

Took 3+4 plugs out, put a bit of petrol in, swapped the plugs over and with a bit of coaxing it started, went for a 20 mile run to clear her out and im now 100% sure the timing isnt out, even by a little bit, she revved all the way to 9k without an issue when it ran, a slight bit of idle issues but that'l be idle screw adjustment that needs doing.

Pretty sure new plugs will help her, might order a set.

Markie, she is running open carbs, the only thing on the inlet side is a bit of mesh jubilee clipped on. Fueling isnt far off enough to be an issue, she racked up lots of miles in all conditions so far this year without failing. I do agree with you though, CV carbs dont really perform there best running open, you get a flatspot that can be moved but never got rid of.

Id put an airbox on but I havent got enough space in my frame for standard K&Ns to be honest, might try and find some flatslide carbs that fit at some point as a compromise.

Cheers for all the help guys.

Cheers
John

 

I think ive sussed it!!

Had a mate over today and he covered 1+2 whilst i covered 3+4 for a change (not been that side before) and I noticed a fuel leak in between the head and inlet manifold 4, a spray of WD40 confirms its leaking.

Set of new inlet rubbers are on there way to me tonight, Maybe i might just be able to get to the workshop on the rat instead of my feet again for once!!

New plugs going in monday afternoon aswell when I get back from work, postman wont have delivered them before I leave

Cheers
John

 

you ordered gaskets for those new boots. correct?

 

good for you. I was going to suggest checking the vacuum line from the petcock...I wrestled with my x one time for 30 mins before seeing the vacuum line off

 

Well its still not working , I had it running today and went for a ride but as soon as it got cold it wouldnt start and needed jump starting.

So far ive:
Replaced ignition pickup, battery, reg/rec, spark plugs, fuel tap
cleaned carbs, set valve clearances, checked timing, sealed inlet manifolds with silicone and pushbike inner tube.

with a well charged battery she starts within 5 to 10 cranks, at first only one or 2 kick in but then she fires in on all 4, backfires through carb 1 a few times then rides fine. as soon as it gets too cold though it wont start at all and flattens the battery before coughing once or twice.


My plan for tomorrow afternoon is to extend the sidestand as she is leaning over quite a bit and then change oil from 20w50 to 10w40 as maybe the thicker oil is making it harder to crank over and start in this cold weather.

Im out of ideas here guys, can anyone help?

Cheers
John

 

Back to basics! Are you "sure" the choke (if you have one) is coming on full at the carbs when attempting to start?

 

it might be a wiring issue cause the batt shouldnt drain like that. i can leave my fzr sitting for 2 months and go out and fire it right up. id check for some kinda short to power somewhere on the bike. maybe voltage regulater

 

EDITOops, just went back and read the first page and realised I'm re-iterating most of what already has been said previously)

If it runs fine when hot but won't start when cold but will start if you put your hand over the air intakes maybe this is a combination of,

1. lack of fuel (enrichment circuit blocked)
2. inadequate current for spark

Test by,
1. reducing the air (choke) to start - putting your hand over the intakes like your doing is the same in principal
2. jumper a charged car/truck battery to your battery to test start

Just jumpering the car/truck battery in will give you some more time to diagnose the fault before the bike battery goes flat too.

I'm not sure how dropping the bike on it's side would cause the problems but if your battery has a bad cell and just isn't putting out enough current then the weak spark will cause major problems.
You may read the correct voltage but under the load of the starter motor you will have a reduced output... on the other hand, when the generator is running, the battery becomes a secondary concern and is only supplying the voltage/current to the ignition system at low revs... which seems to coincide with your problem fairly well.

 

the backfiring is caused by a lean condition. mine was popping the vacuum caps off. you probably don't have a good seal with the silicon and ruber tube. you would have been better off buying gasket material from the autoparts store and making your own gaskets. that's going to be quite the mess to clean off. and silicon don't last forever. it dries out and cracks.

that #3 is probably sucking in air where it shouldn't.

 

Re: xj600 (fj) 92 still wont start, loosing faith with this

This is at the heart of your problem and will continue to be until corrected. At the very least you need some form of velocity stacks if you're not going to run air filters of some sort.

Running purely wide open carbs will subject you to the possibility of clogging the microscopic air holes in the carb throat, as well as making the motor VERY sensitive to climate changes and cold in general.

 

Adrian, Not 100% sure of the choke by means of stripping them all out but the motor certainly responds to choke as it always ever did before the fail began, revs higher on choke when cold, bogs and dies when i pull the choke with a warm engine etc.

CDS, pretty sure the electrical system is in good condition, the only thing that doesnt match specs ive found on the forum is the tci voltage under cranking but its always been at that voltage under cranking (tested when i got it)

Fitz, Not wanting to call your bluff but she has done 20 odd thousand miles this year running open and never became harder to start even at 3am leaving friends houses. I'll make some velocity stacks up and a thin piece of filtering material though and see how that goes. Do you suggest filtering material at the carb end of the velocity stacks or the intake end?

Cheers
John

 

What I would suggest short of reinstalling the airbox would be pods at the very least.

The original rubber airbox-to-carb boots make very effective velocity stacks, even without the airbox there to connect to.

I would filter at the intake side of whatever stacks you come up with.

Twenty thousand miles or only twenty, it doesn't take a very big particle to clog some of the TINY passages in the outer throat of a Mikuni.

Speaking of 20K miles, when was the last time you adjusted your valves?

 

Unfortunatley I havent got enough space in my frame to fit an airbox or even pods, being a bit of a rat she hasent even got enough space for a pvc plumbing manifold.

I'll do my best to try and make some velocity stacks this weekend, fingers crossed that will sort it out.

Cheers
John

 

Hey Virus,
Can you post some pics? That'd be great!
My imagination has your bike looking like a Mad Max type affair for some reason.

 

Your imagination serves you well chap.

 

Mad Max called... he wants his bike back.

 

mad max didnt have a bike :wink: :lol:

Watched those films waaaay too many times i think. :lol:

Cheers
John

 

virus, have you tried a compression test? sounds like you havwe bent valves