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bike newbie... help needed!


trainor
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greetings to all. Very happy to find this site straight away!!

just got my first road bike, fzr600, 1989, ive been head over heels for these bikes since i was about 5, when my dad had one and ive been managed to grab one which is pretty much exactly the same as his that we can both strip and restore!!

I bought the bike off ebay as a non-runner/starter. it has pretty much full tax and mot and has been used reguarly until it wouldnt start one day...hence the sale.

i have now started to look for what thye problem is.... i have, so far tried...

engine turns over fine when tring to start, the most youll get is a backfire.

checked all 4 plugs all ar ok. and all are sparking when you try to start.

i have taken off main fuel hose to carb fuel fail, turned to run and this spurts out fuel for about 4 secs and looks like a priming sequence.

i then put back together and tried to start... still the same.

i suspected lowq fuel pressure or a blockage in the fuel rail maybe, so i put a little fuel into each carb via air inlet and tried again, still not even a splutter

any ideas??? i was sure id get at least a caugh out of it but nothing. as this is my first bike i dont know much about the tech side of things so help would be much appreciated.

heres the beast....

Photo0009.jpg

thanks alot, aaron.

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  • Moderator

Are the plugs wet with fuel?

Is there a spark?

Have you emptied the tank and put fresh fuel in it?

Have you changed the plugs?

Get some easy start, take the air filter out, squirt and turn over? If you get a splutter you are part way there.

I would guess carbs at this stage.

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Hmmm, its the backfire that makes me think you maybe have perished rubbers, posibly diaphrams. I would be looking at the carbs first rather than anything else yet.

As already said are the plugs wet when you have tried starting the bike, and much as you say they are sparking there is quite a difference between a nice blue spark you can hear and a woosy little orange thing that wouldn't light a gas ring.

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thanks 4 compliments! :)

now u come to mention it, it isnt a good blue spark that is audible as u describe. how can this be rectified?

and the previous owner said it recently had carb rebuild...clean and new seals.

when i first took the plugs out they did look damp butnot drenched.

aaron.

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havent tried a push start, would that make any difference then??

and if it cos of a weak spark, would changing coilc, leads and polugs solve that one?? or can a weak spark be due to other things. cheers

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havent tried a push start, would that make any difference then??

and if it cos of a weak spark, would changing coilc, leads and polugs solve that one?? or can a weak spark be due to other things. cheers

Start with the cheapest and work back, the first 2 of which during ANY engine problems is change the plugs and charge the battery, next if the caps will unscrew from the leads and if there is some spare length. Unscrew em and chop 10-15mm off and re fit the caps. Lastly check the frame earth for the coils as a shite primary voltage will give a shite secondary (at the plugs).

Thats 90% of the weak spark issues after that it gets expensive/complicated. Cdi units, primary coils, pulse coils. Nothing that usually gives trouble. Yam rectifiers can go flaky and cause difficulties.

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Start with the cheapest and work back...............

This should be the forum's mantra.

It is amazing how expensive it can get by trying all the bits it could be.

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This should be the forum's mantra.

It is amazing how expensive it can get by trying all the bits it could be.

I'd agree in some instances but not this one, plugs should be changed anyhow when you have problems. Charging the battery, the leads and the coil earths are zero cost options and can cover most of the weak spark issues. After that we should have some better/accurate info to dial into the problem.

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hi, after the advice given, i spent a little time on the bike today...

changed the fuel to fresh stuff just to be sure.

snipped off 10mm on each plug lead, put caps back on.

new plugs.

i am assuming the bracket that holds the coil on to the frame is its grounding point, i removed that and cleaned up all mating areas.

tried to start and there was a breakthru... it did splutter for about 3 secs then nothing again. i really thought that id sorted it :( lol

then shot round the spares shop got some easy start and tried that, nothing at all again.

so iv had a splutter which is more then ive ever had so must be in the right direction. i am thinking its cos of a weak spark as you can see fuel entering each carb inlet when u crank it over and plugs are wet when removed so im defo thinking ignition prob....

any more thoughts on what to do next?? coil pack and leasds?? i have noticed on the coil it has writing in white pen, the model etc '3hu' which im assuming has been fitted from a 2nd hand bike spares in the past.

thnks, aaron.

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hi, after the advice given, i spent a little time on the bike today...

changed the fuel to fresh stuff just to be sure.

snipped off 10mm on each plug lead, put caps back on.

new plugs.

i am assuming the bracket that holds the coil on to the frame is its grounding point, i removed that and cleaned up all mating areas.

tried to start and there was a breakthru... it did splutter for about 3 secs then nothing again. i really thought that id sorted it :( lol

then shot round the spares shop got some easy start and tried that, nothing at all again.

so iv had a splutter which is more then ive ever had so must be in the right direction. i am thinking its cos of a weak spark as you can see fuel entering each carb inlet when u crank it over and plugs are wet when removed so im defo thinking ignition prob....

any more thoughts on what to do next?? coil pack and leasds?? i have noticed on the coil it has writing in white pen, the model etc '3hu' which im assuming has been fitted from a 2nd hand bike spares in the past.

thnks, aaron.

Good, were aiming at the right target then, the white pen is prob from a breakers and is most likely (being optimistic) from the fellow that had it previously trying to fix it.

Have you had a route round at the connections to the coil, the fact you have a spark however weak means the cdi is probably good, again being dangerously optimistic.

We do have a possible second reason for it not starting now though, the cylinders may have a large amount of liquid fuel floating around in there that the motor couldn't burn and snuffed it out. Spin her over with the plugs out to blow the cylinders clear. You may be surprised at the amount that is blown out. When it clears dry out the plugs, run a feeler gague through em to be sure they are clear and have another go at starting just to be sure.

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Leave the plugs out overnight if there is no risk of water getting in. If easy start into the airbox didn't do much then a weak spark would be next (I hope when you easy started you took the air filter out).

Follow the wires back to the CDI to make sure that the wiring is OK and not damaged, earthing out or badly connected. Then I would be looking for new coils.

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All this attempted starting can and will wash away any oil in the cylinder lining / piston rings. Couple that with a degree of mileage and some wear and compression will be reduced causing hard starting. Take out each plug, squirt some oil in each bore and spin the engine befor the next starting attempt.

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MAJOR BREAKTHRU :)

decided to trace every bit of wiring and connections for breaks, bad earths etc. found a snapped wire... re soldered, tried it and it started first time lol. sounds absolutely awesome and running beautifully so i decided to put it all back together..... now another problem.... :(

got as far as the top of my driveway riding it, and died, went to start again and u have to give it loads of gas to get it to run and will not go over idle even tho gas neally fully open (sounds like missfire/running on less than 4 when this is occuring!) but this soon clears and revs and idles sweet again, until u try to ride it and put load on the engine! then same thing starts again.

so any thoughts on this then??

SO close, but yet still so far away :(

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