Gsxr 600 srad surging at constant throttle - SV650.org

10-12-13, 07:35 PM

Ive had a problem on my 1999 gsxr 600 since ive been riding it, but fairly inconsistently until recently. Over the last few days its become a bit more common, the problem is that on constant throttle between 30-40mph the bike does what i can only describe as a surge. The throttle position is constant but the bike will get in a rhythm of dropping power for half a sec or so, then getting power back again for half a sec or so. If i accelerate slightly the problem will go instantly.

Ive bought some redex on the off chance itll save me some bother but ive read before now that its not much cop.

Im thinking its a fuelling issue, something to do with the carbs... Should i look at balancing at the first step , or is there any other ideas ?!

Wideboy · 10-12-13, 09:49 PM

balancing is the easiest and cheapest thing to try first providing you have gauges. My thunderbus used to do it when cruising at 80-90 on the motorway, a coil was breaking down.

andrewsmith · 10-12-13, 09:51 PM

Carb balance by the sounds of it. My SV does that when they drop balance

10-12-13, 10:32 PM

Yeah ive got a set of balancers and my dad knows how to do it so i think thats next port of call..will report back when ive done it, cheers guys

yorkie_chris · 10-12-13, 10:34 PM

I'd suggest an intake air leak as a possibility or other sort of lean running. Or possibly some crap in the pilot circuit/low speed needles.

10-12-13, 11:04 PM

Ok, will invsetigate further for that if nessacery after i balance it.

johnnyrod · 11-12-13, 01:23 PM

Yep worth checking the balance but as YC says it sounds a bit lean. How was it in the other recent cold weather? I think the carbs have a sort of plate heater to try to prevent icing but it's crap, so the cold air (especially when moist) coming in through the scoops can overpower it. If it hasn't packed up, of course. Redex, waste of time, fix the mechanical problem or if you suspect carb heat problems then try a bit of Silkolene FST (isopropanol) or equivalent.

11-12-13, 04:53 PM

Been fine in the other recent cold weather but thats mostly been above 30/40 where ive had the issue

yorkie_chris · 11-12-13, 04:57 PM

Carb icing doesn't make it surge, IME, it makes it fall on it's backside when you open the taps to overtake or go up a hill or something.

11-12-13, 07:24 PM

Also presumably youd only get that at sub zero temps, which it defo wasnt the last 2 times ive had it

10-12-13, 07:35 PM	#1
stuR Guest Posts: n/a	Gsxr 600 srad surging at constant throttle Ive had a problem on my 1999 gsxr 600 since ive been riding it, but fairly inconsistently until recently. Over the last few days its become a bit more common, the problem is that on constant throttle between 30-40mph the bike does what i can only describe as a surge. The throttle position is constant but the bike will get in a rhythm of dropping power for half a sec or so, then getting power back again for half a sec or so. If i accelerate slightly the problem will go instantly. Ive bought some redex on the off chance itll save me some bother but ive read before now that its not much cop. Im thinking its a fuelling issue, something to do with the carbs... Should i look at balancing at the first step , or is there any other ideas ?!

10-12-13, 09:49 PM	#2
Wideboy Evel Knievel Mega Poster Join Date: Jun 2007 Location: Eastleigh Posts: 4,641	Re: Gsxr 600 srad surging at constant throttle balancing is the easiest and cheapest thing to try first providing you have gauges. My thunderbus used to do it when cruising at 80-90 on the motorway, a coil was breaking down. __________________ 05 DRZ400E RIP hovis

10-12-13, 09:51 PM	#3
andrewsmith Member Mega Poster Join Date: Apr 2010 Location: Newcastle upon Tyne, Just south of salad dodging country Posts: 7,750	Re: Gsxr 600 srad surging at constant throttle Carb balance by the sounds of it. My SV does that when they drop balance __________________ RIP Reeder 20/07/1988 - 21/03/2012. Always missed squire!!! Every year we meet old friends, gain some new ones, lose old ones and you always remember them all. “Live as if you were to die tomorrow. Learn as if you were to live forever.” Mahatma Gandhi

10-12-13, 10:32 PM	#4
stuR Guest Posts: n/a	Re: Gsxr 600 srad surging at constant throttle Yeah ive got a set of balancers and my dad knows how to do it so i think thats next port of call..will report back when ive done it, cheers guys

10-12-13, 10:34 PM	#5
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: Gsxr 600 srad surging at constant throttle I'd suggest an intake air leak as a possibility or other sort of lean running. Or possibly some crap in the pilot circuit/low speed needles. __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

10-12-13, 11:04 PM	#6
stuR Guest Posts: n/a	Re: Gsxr 600 srad surging at constant throttle Ok, will invsetigate further for that if nessacery after i balance it.

11-12-13, 01:23 PM	#7
johnnyrod Member Mega Poster Join Date: Jul 2003 Location: Doncaster, oop norf Posts: 2,128	Re: Gsxr 600 srad surging at constant throttle Yep worth checking the balance but as YC says it sounds a bit lean. How was it in the other recent cold weather? I think the carbs have a sort of plate heater to try to prevent icing but it's crap, so the cold air (especially when moist) coming in through the scoops can overpower it. If it hasn't packed up, of course. Redex, waste of time, fix the mechanical problem or if you suspect carb heat problems then try a bit of Silkolene FST (isopropanol) or equivalent.

11-12-13, 04:53 PM	#8
stuR Guest Posts: n/a	Re: Gsxr 600 srad surging at constant throttle Been fine in the other recent cold weather but thats mostly been above 30/40 where ive had the issue

11-12-13, 04:57 PM	#9
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: Gsxr 600 srad surging at constant throttle Carb icing doesn't make it surge, IME, it makes it fall on it's backside when you open the taps to overtake or go up a hill or something. __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

11-12-13, 07:24 PM	#10
stuR Guest Posts: n/a	Re: Gsxr 600 srad surging at constant throttle Also presumably youd only get that at sub zero temps, which it defo wasnt the last 2 times ive had it

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