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Discussion Starter · #1 ·
Hi Guys,just new to the forum.I`ve a 91 gsxr 750m and it`s giving me probs with the idle to 3000 rpm range.It`s an import which doesn`t help but I`ve tried everything like stripping carbs,checking electrics etc..any idea`s? I`m in the UK.Also I don`t know how or if the bike has been restricted in the past but it has a live feed from the battery running to an orange wire behind the battery.I hope you guys can help,I love the bike,but I`m just about at the stage where I`m gonna order a second hand 1100 motor/carbs/loom/clutch stuff etc!! haha!
 

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Did you run through your pilot jets with a wire, and then blow them out with air? Are your mixture screws at least two turns out? Do you have pod filters or the stock airbox?
 

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Did you run through your pilot jets with a wire, and then blow them out with air? Are your mixture screws at least two turns out? Do you have pod filters or the stock airbox?
all good, but add float levels to the list
 

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did you adjust the idle.??
mine I got to turn the idle up a bitwhen I first start it. after a few minutes the idle slowly jumps to around 3,000 rpms. then I turn down the idle, and raise some hell
 

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Discussion Starter · #6 ·
Thanks for the input.I`ve had the carbs stripped a few times and everything seems fine.As I said the bike is an import and has the standard airbox and filter.I checked all the jet numbers and they don`t seem to tie up with anything in the workshop manual.The mixture screws are 1 1/2 turns out and the carbs are well balanced.The mains are 120,needles 6ze11 on the middle clip,pilots 35,emulsion tubes 631 p-11.Any ideas? I`ll try and find out where the bike was imported from if that would help.Thanks for the kind offer of taking a look at it but I`m in Northern Ireland.
 

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Discussion Starter · #7 ·
Sorry,I forgot to say.The problem seems to get a little worse as the bike warms up.I thought it might be running a little rich but I`ve tried the mixture between 1 and 2 turns and it just seems to make it worse.I also checked the electrics just in case it was something breaking down when hot.Are there any common probs on these bikes with triggers,coils etc?
 

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Sounds like you are lean on the idle circuit. You need to continue to back your fuel screws out to richen up this part of your circuit. When the bike is warmed up will it idle at 1000-1500 rpm? If so just quickly blip the throttle, then look at your tach to see how the needle falls back to idle. If it is real slow or hangs then you are lean, if it is fast and actually falls below your idle point then move back up to that point then you are rich. Good luck.

John
 

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Some possibilities in the ignition system (I've tried every one of these on my '91 750) are:

1. Stock coils and plug wires are integral. Wires could be old and cracked or have a bad connection to the plug cap. Trimming down the ends of them and re-screwing the caps back on more securely could help.
2. Disconnect all the connectors for the signal generator, the ignitor box, the circuit breaker and anything else you find under the seat/behind and under the battery box and spray the crap out of them with contact cleaner.
3. A failing signal generator (located under the smaller front cover on the right side of the bike) will heat up and start sending squirrelly voltages to the ignition box causing the bike to run OK for a while then act like it doesn't want to run except at high RPM. Somewhat expensive for and OEM replacement, but it's the same Suzuki part number for every oil cooled Gixxer and Bandit with the exception of the short-stroke 750s and the 1052cc 1100s, so you should be able to source one from a motorcycle junk yard if you have access to one.
4. One final thing to check while you're under that particular side cover is the torque on the large Allen-head bolt that holds the ignition trigger in place. If it backs out, it will wobble slightly on the crankshaft end, causing erratic input to the signal generator. If the previous owner ever had occasion to remove the ignition trigger, or if he replaced it with an aftermarket advancer, it's possible that it's loose.

Good luck,
Bill
 

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yeah try the coils and the pick up coil in front of the clutch cover want the (good part) specs when testing with a multi meter.??
 

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Discussion Starter · #13 ·
Can`t thank you lot enough for the suggestions.I`m no novice working at bikes and I regularly help people with probs but this has me stuck.The frame number is:GR7AC-101701 and the engine number is:R719-101725.I was gonna buy a dynojet kit and try to get the carbs back to `normal` but with solid emulsion tubes and God know`s what else I realised that I needed some more info first! I know I`m new and can`t really help you lot out with gixxer probs but I`ve worked and tuned at A LOT of other stuff so I hope I can help you guys out sometime!haha! thank`s again.
 

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Discussion Starter · #14 ·
I`m sorry I know I said the bike was `91`-it is in the reg book,but to me it is `92 which as you know is an`m`.
 

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Discussion Starter · #15 ·
Hi Guys,just about to go out to the garage and check the coils,trigger etc. with my multimeter.If it`s any help I took the bike out yesterday and found that when you roll on the throttle below 3500 rpm the bike just wants to die.It`s hard to describe,it`s like it`s missing or something.Even at 40 or 50 in 6th,when you move the throttle at all it won`t accelerate and you have to drop gears to get it going.It sort of surges.Hope this helps.
 
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