ignition fault?

[carl t]

Hi all! need some help got blandit with 1127m motor fitted and has been playing up of late (again). Been having some rough running issues lately which felt like the battery was dying, replaced plugs, coils and battery also some issues with the wiring harness due to the efforts of the chimp that butchered it to accommodate the gsxr cdi and some comedy headlights. After sorting the loom the petcock let go and flooded the crankcase. Since then the bike wont start. got fuel, nice fat spark just wont catch. anybody any thoughts on a bad earth causing plugs not to fire when fitted.  I know im clutching at straws but im reaching the end of my knowledge.  Id be grateful if anyone could point me in the right (or any) direction, even a scrapyard!! cheers all

[dougw]

Does it fire on any cylinder , or at all, or backfire ? Remote diagnosis is not easy !

if it’s not firing at all then unless both coils have failed it’s something that’s common to both coils , eg cdi or pick up. Always worth trying some new plugs, they can spark when out of the cylinder and still not fire when in place. Don’t know if you can get “easy start” spray anymore , a blast of that would rule out fuel not right if it fired up briefly with that. As you have mentioned , check earths and all connections thoroughly. Good luck !

[carl t]

Thanks Doug it wont fire at all but all plugs give a great spark when out of the cylinder, ive triple checked all the remedial work ive done to the loom and  the petrol was fresh two weeks ago after the petcock failure. ive tested the coils and the wires from the pickup and all show the correct readings according to haynes. i threw the old plugs back in just to test them and im loathe to take it to a local garage as im stubborn and from previous experience theyve all been a set of thieving bastards. it will backfire once the fuel in the bores builds up enough but she just wont start. ive also cleaned and checked carbs twice all seems ok so im just stumped now. electrics is the devils work.

thanks again Doug, cheers

[jameskat]

It may be a stuck float needle causing a flooded carb and an over rich condition.

[carl t]

Im pretty confident that the carbs are operating correctly as ive cleaned and checked them twice although one of the symptoms of the rough running I was experiencing was the bike was feeling as though it was running out of fuel  or not burning it hence the new coils  battery etc  and petcock after the bike flooded the gearbox. Even if the timing was an issue id still expect the bike to run at least badly  though it was running sweet beforehand. maybe its time to drop a lit match in the tank!!!

[fatblokeonbandit]

double check the coil connections first, ever so easy to get them mixed up and not have 1&4 and 2&3 connected up to the right feeds..

[carl t]

Thanks mate already checked that, I'll double check pulse generator just to be sure tho.

[fatblokeonbandit]

have  you tried it with an auxiliary fuel tank to eliminate, the tank, breather, tap and vacuum system?? I use a big syringe, not forgetting to blank the vacc feed???

[carl t]

IveTried a remote tank had the same problem Ive currently stripped the sheathing off the loom backwards all the way to coil leads as it's pretty shonky  with how it was butchered and even if I don't find any issues at least I can eliminate it and move forwards towards the controls. The PO had fitted dominator h/lamps and coiled the surplus of the wiring harness round the top of a hot engine so I suppose anything could be going on in there, otherwise I'm clutching at straws right now. The only things I haven't checked with multimeter are the relevant individual wires and the cdi which I understand can't be checked but either work or they don't. Thanks for taking the time to reply tho mate 

[fatblokeonbandit]

so in the first bit you said the loom was sorted. did it run fine then?? if you flooded the engine with petrol did you fir new plugs, they are notorious for not working when cover in fuel, even though they spark

[RUSSP]

If you have a good spark it sounds to me as if its a fuel problem, will it fire if you spray easy start (you can still get easy start from most motor factors) into the carb inlets if it does then I would guess its a fuel problem worth a try

[carl t]

I thought the loom was sorted but I must admit I'm just trying to make sure and make the best job I can of it. There were issues around the headstock area connector blocks and also where the cdi  was spliced into the loom  but all seems to be good now. The flooding happened whilst I was going for a test ride after fitting the new coils and plugs and waiting for a new battery to arrive via courier and came back with an air box full of petrol so I can't rule anything out definitively. As for the fuel, after I rebuilt the petcock I filled a can as I was filling up the wife's car so I'm assuming the fuel is good. Maybe it's time to get some easy start and go from there but if the fuel is bad I must have had a really bizarre run of bad luck with the bike pixies or I've gotten myself into a terrible muddle!

[Captain Chaos]

try new plugs first as FBOB says. They may look fine but still be f@cked, these oilcooled Suzuki's are real picky when it comes to plugs and throw them out for no apparent reason. Starting on a low-ish battery for example can kill the plugs.

[clivegto]

Plugs as said if flooded they don' like it is my bet.

[carl t]

Thanks guys hopefully new plugs and fresh fuel will cure it once  ive  finished tidying the wiring up. fingers crossed !!!

[carl t]

Result!!! fitted new plugs it fired straight up, however, its running really rich.

1127m/n

bst36ss jetted as per gsxr1100k/l

3rd clip from top

2 turns out.

standard blandit airbox  with 2 x 5cm holes drilled

hifiltro oem spec filter.

I dropped the needle to second clip, mixture screws in to 1 3/4 turns and is much better yet still rich and has lean pops at idle. I was wondering if the air filter is kaput. its around 12 months old with around 4-5000 miles on it surely I could expect more mileage from a filter or could my shiny new coils be er...... shit?. When the bike started playing up it was a gradual worsening over about 2 weeks. thinking about going back out on mixtures and pulling out the snorkel whilst I get a new filter Any thoughts?

[fatblokeonbandit]

what size main jets you got in, and tape the holes up, it cant be lean and rich at the same time????

[carl t]

I have 125 main jets, 40 pilots, micron 4-2-1 system with toro silencer with baffle have been playing with jetting recently has been running quite well just a little boggy at the bottom end which I am intending on cleaning up but free time has been an issue. Also jets, needles and emulsion tubes are very recent as I bought the bike as a stock bandit so it came with standard gsf jets. P. O. Had swapped out the engine out.