GK76A Ignition

[ripzay]

Hi guys, i'm having issues with my '94 GK76A

The spark plugs are getting wet, so there is deffinitely fuel going to them.

I have tested the spark plugs and all four spark outside of the bore, but i'm having issues starting the engine..

once started it seems to idle and run fine. its getting to the point where i'm running the battery down before it will start now which is annoying.

i will get massive backfire through the exhaust sometimes when cranking too..

my questions:

1) to test my coils, what resistances should i see over the primary and secondary
2) with regards to the sparks themselves, how big / bright and what colour should they be ? at the moment they dont seem spectacularly strong, which is what's making me think the coils are bad.

also, of the two coils, the coil for cylinders 2 and 3 seems to get much warmer in use than the coil for cylinders 1 and 4

This might be a cold weather issue but i need to get it sorted as shortly this bike will become my only mode of transport for a while - i would buy a cheap 125 for my commute but i don't have the money at the moment.

Any help is greatly appreciated.

Thanks

Ben

[wullvfr]

hello mate-

im guessing when you are starting the bike it's with the choke on and no throttle?

also after the bike starts and idles for a while,does it re-start very easy?

the backfiring would indicate unburnt fuel but because it finally goes it definately seems that the spark is possibly weak!!!!

but definately make sure the choke is working correctly as this will affect cold starting.....making it a nightmare to start.

for coil resistance,primary coil resistance should be between 2.5-3.5 ohms and secondary resistance with plug cap 14.0-25.0 k ohms.........

try with another set of plugs and see if that makes any difference......

when the bike is finally started and runs ok that to me says the coils are alright,but i would definately check that the choke is working correctly as well


william

[ripzay]

Quick update.

I tried and tried and tried, checked all the plugs, leads, coils, cleaned old plugs, new plugs, EVERYTHING i could do electrical

and have given up..

i've handed the bike over to a friendly bike mechanic (he doesnt have a dyno to do a proper tune but he should be able to get it running at the very least).. carb setup is beyond my capabilities so i've called in the experts.

he's going to look at it tomorrow and hopefully it will be running by weekend then i can take it to be properly tuned.

fingers crossed.

Thanks.

Ben.

[wullvfr]

keep us posted mate.........how did the bike run after it was started?

any flat spots,bogging down etc?



william

[ripzay]

once warmed up it would rev up and settle back at idle without any hesitation
throttle response was as expected.

i can't comment on how it was under load though, because i've never ridden it!

has been sat in the garage waiting for me to pass my test (which i did today)

it was working fine up until about mid december, i went up weekly to start and warm it up, to make sure it worked when i came to ride it, and had it on a battery tender.

[wullvfr]

waiting for me to pass my test (which i did today)

congrats on passing your test mate,must have been freezingyer balls off

let us know what yer mate finds!!!!!



william

[ripzay]

waiting for me to pass my test (which i did today)

congrats on passing your test mate,must have been freezingyer balls off

let us know what yer mate finds!!!!!



william

Thanks, and i will do.

[ripzay]

you could say i may have found half of the problem!

got a replacement for the blown transistor package on its way, should be here tuesday/wednesday with any luck!

rather pay £1.50 for a transistor on the off chance that replacing that will work, than pay £80 for a new CDI.

on that subject, does anyone have a GK76A CDI spare ? just in case!

thanks!

Ben

[wullvfr]

i dare say that may have been the whole problem.....good find!!!!

once you get that replaced then you will hopefully be up and running no probs at all

have a wee look on ebay for a cdi failing no one on here having one



william

[ripzay]

there are some de-restricted ones on ebay, from hong kong at £75+£14

but seeing as the one i have is such an item and it has failed i would rather not pay that much just for it to happen again, i'll look out for a suzuki unit
maybe ring around some breakers..

hopefully the one i have can be salvaged!