Suzuki GSXR400 starting problems

[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

P.S. i have posted this topic on 400greybike too but figured more coverage is best to get an answer - using the two heads are better than one logic
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Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[drew70]

Speak to Stripes1976 on 400gb or www.gsxr400.com he helped me out loads a few years back when i had a 76a. Btw most probs with these bikes are carb related.
good luck

[Wafer_Thin_Ham]

I can only echo what Drew's said to be honest. Stripes is a good bloke, although I haven't heard from him in a while.

It could well be the O rings in the carbs have perished, are letting through stupid amounts of fuel and flooding the bike preventing it from starting.
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[ripzay]

wouldnt the notorious O-Ring issue cause bogging down under acceleration and bad idling problems...

when it runs (and it has, and does run, its just a pain in the arse to start) it runs smoothly and as it should.and there are no signs of it running rich. no smoke from, the exhaust and no smell of unburnt fuel.
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Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[Wafer_Thin_Ham]

[bladerunner]

Well I think everyone has mentioned the O ring thing then!! As for how good a spark. it should be able to jump at least 8mm from the end of the HT lead to earth ie no cap. Nice fat blue one is ideal

And just to make sure have you tried fitting new plugs?Maybe a couple of them are on there way out.
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Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

[ripzay]

i have checked all four plugs and all for spark on their respective lead outside of the bores - i even got a shock a couple of times but i'm persistant!

i have tried with botht he old NGK standard plugs (cleaned and gapped correctly) as well as new NGK iridium plugs, both are as bad as eachother in terms of starting)

as for the choke working correctly, i presume so... once the bike is running it does what a choke should do - revs get higher as the bike warms up until i back the choke off at which point the drop

once the bike is warm with the choke fully off it idles at about 1100-1200, as set by the throttle adjustment under the carbs.

I've had the battery on a tender for the last few days to trickle charge it back up and i will pop down and try it again tonight, i'm hoping its just a low power issue causing the trouble and that a new battery will sort it.. i'll keep you updated.

i've never tried testing the spark with no cap / plug, is that a good idea? i presume the HT leads themselves have enough resistance to not burn out the coils testing this way ?

any other suggestions welcome!
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Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[Thom]

So what your saying is the bike is hard to start but when its running its fine, does it bump start?

If so im saying its your starter motor to be honest.

A mate of mine has a gsxr4 track bike which he hadthis problem with and it turned out the starter brushes wereworn beyond limits.

Edit: just realised the plugs are getting wet which suggests not sparking, my mistake...
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

[ripzay]

i cant bump start it because i'm not allowed to ride the bike on the road (test on thursday) and i dont want to risk it because of where it is, the only place to bump start it is on a busy main road.

my GUESS is that it would bump start ok, but i couldnt say.
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Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[Thom]

you only need a very short piece of path to bump it. i can bump my 400 and my old gs on a 6metre long drive easily.

but if you think it will start with a bump im saying starter motor.

What exactly do you get when you press the starter button?
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

[ripzay]

turns over as it should, as fast as it should until the battery starts to die.

starter motor appears to be fine really.
____________________
Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[Thom]

id get that battery fully charger and try again then, because if it will bump then it sounds like its just not getting enough power from the battery in the first place!

Will it run on easy start/carb cleaner?
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Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

[Cigaro]

[TUG]

As bass said, could possibly be the coils? Hmmmmmmz had a problem like this on his ZXR IIRC an he fixed it with a new set of plugs because he bought a duff set?
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Haz ER-5, innit!

[ripzay]

Hi guys, quick update.. i'm stumped now.


i've checked all the spark plugs, all are DEFFINITELY sparking

now when i press the ignition the bike sounds like it's burning away the fuel where as before it sounded like it was just turning over

however it still wont catch, it sounds like it has caught every now and again, but doesnt stay running...

i'm starting to think it's a fueling issue but i suck at carbs, these ones particularly, i just dont know where any of the adjustment is apart from the idle air screw.

my battery was giving a constant 12.64 volts (and not dropping with the ignition turned on, so i dont have a leak to earth anywhere)

it stayed at just over 12 volts while turning over the engine but after half a minute of trying to start it had dropped to under 12 volts
and my battery tender said that it had half of its power left in it.. i'm thinking it might be a combination of a crap battery and bad carb setup

i'll hope it bump starts and buck it in at one of the local bike tuners for a carb setup and dyno run session i guess. i've had enough of it myself!

out of interest i took the top covers off a couple of the carbs to inspect the diaphragm, slider and needle conditions and all looked perfect to me.

one thing i havent done is taken the carbs off the engine and given them a clean but looking down the top of one with the slider + diaphragm out they look clean.

i drained all four carbs with the tank off, replaced the tank and turned if over a few times, the drained fuel was clean and free of particles, and the float bowls filled back up again after a few turns of the engine.

i'm at the end of my ability i think, time to call in the pro's.
____________________
Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[Thom]

It sounds likeit's "Burning fuel"?

If the plugs are wet and the plugs are sparking it sounds to me asif the cylinders are flooding and this is why you cant get it to run.

Close the fuel lines and try starting the bike with easystart, although this is a crude test if it runs on that then i'd say it's your carb settings. (Perhaps altered the mixture screw instead of idle?)
____________________
Current Bike: 1996 Yamaha TRX850 (The Japanese-Ducati One).
Previous Bikes: 1990 Honda NSR125 'Rothmans' (The smoking one), 1990 Suzuki GS500e 'Caf? fighter' (The loud one), 1987 Kawasaki GPX400r (The quick one), 1997 XJ600s Diversion (The reliable one), 2000 Kawasaki ER-5 (The spontaneously combustive one)

[Wafer_Thin_Ham]

DO NOT USE EASY START.

It can snap the rods on the 76a.
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My Flickr

[ripzay]

well guys

I passed my Category A test today, but the bike still wouldnt start, guess i used up all my luck on the road!

i've taken the bike down to a friendly mechanic (runs the local bike club and is a friend of the family) he's going to jump straight to it tomorrow morning and hopefully have the thing running for next week..

Whats worse than having a bike waiting for you to pass your test...

having a bike and licence and still not being able to use them!
____________________
Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[bladerunner]

Well congrats on passing your test. you can always get another bike anytime you want now!! Fingers crossed the gixer gets sorted though!!
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Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

[Pete.]

Same carbs as the bandit 400 I think. My sister's bandit was the same and I cured it completely by sorting the carbs. Main thing was in the bottom of the bowl there is a tiny jet set in the plastic housing that holds the float and each of them was blocked. That and setting the float heights made it start every time.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[ripzay]

https://www.binary-pulse.co.uk/Random/Bike/Pics/CDI/damaged-cdi1.jpg

https://www.binary-pulse.co.uk/Random/Bike/Pics/CDI/damaged-cdi2.jpg

https://www.binary-pulse.co.uk/Random/Bike/Pics/CDI/damaged-cdi3.jpg

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
____________________
Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[tractor664]

hi.. try e-bay was a cdi unit for 15 quid (not mine) . i was looking for bits for my gk73.. have running probs too .plugs on way carbs off at week end ..
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never give up trying to find the perfect corner

[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!
____________________
Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[ripzay]

Hi guys.. quick question...

the coils on a GSX-R400 GK76A..

where the hell can i buy one from if mine are a problem..

are there other bikes that use the same coils, preferably want something i can walk into a bike shop or stealership for rather than waiting for postage.

Thanks!

Ben
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Current: 2005 KTM SuperDuke 990
Previous: 1996 Suzuki Bandit 600
Previous: 1994 Suzuki GSX-R 400

[Blau Zedong]

Any GSXR / GSXF / Bandit coil should work. I know some GSXR750's use EXACTLY the same coil as the 400.
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18:54:48 Rob Fzs: jews don't give away stuff for free

18:54:59 Rob Fzs: unless its their clothes/ hair/ golden teeth