: gsxr600 hesitation/flat spot below 2000rpm
bucket 09-27-2007, 04:00 PM HI there need help badly, when taking off i need to plip the throttle to get going. If i try to move off normaly its like a bucking bronco until i get over about 2000rpm then its fine. Hot cold makes no differance. No mods except can. feels like its flooding, tried giving choke when fault appears but just the same. Tried other carbs but ran worse up the throttle range and still have the original fault but don`t trust these carbs. Please help
oldnick 09-27-2007, 04:49 PM Clean & gap the plugs. Check the pilot screws. Try closing them all and then open 3 turns. Wind 'em in or out from there 'til you get a nice smooth idle. Try it then. If it still does the same, check the float heights. Is it the same with a standard can, air filter or what. Which model? Strange hot / cold dosn't affect it, also choke. Check the solenoid valves (if fitted). What is the tickover?
twopoke 09-28-2007, 05:15 AM my bike is like that, flat spot below 2k. it dont jerk its just flat. every gsxr 600 srad i have been on is the same (been on 5 different bikes)
my bike has dynojet in carbs set on the dyno, they are just very flat below 2k
i mean...... think about it the limiter kicks in at about 14k......why would you want to be below 2k anyway?
bucket 09-30-2007, 01:31 PM Hi, thanks for replys. My bike model is `97 600 SRAD. New plugs fitted, adjusted the pilot screws (idle has always been smooth at 1200 rpm), same with standard can, It has the solenoid valves and vacuum pipes but no electrical connections is this normal? When i say hesitation/flat spot it only happens when stopped then moving off and the fault lasts for about 4 to 5 seconds jerking till the revs get over 2000rpm. No matter how much or little throttle (surely this isn`t normal). Going to try balancing carbs with gauges but any other help would be useful. Thanks
THE SRADIATOR 09-30-2007, 01:34 PM I suspect a carb sync may be in order?
-Kristo- 09-30-2007, 01:54 PM I have exactly the same problem with GSX-R 750 '97 (SRAD). Changed spark plugs, cleaned carbs but the problem remained. Next, I try to lift needles. If this doesn't help, then it's time to bring the bike to proffessionals :)
Sorry for my bad English, im an Estonian.
-Kristo- 10-24-2007, 08:12 AM I think I found the problem. By bikes so called "intake manifolds" (rubbers between carbs and head) are leaking. In my opinion, extra air is coming from there and that causes the flat spot. Bucket, I recommend you to check those things too (if you understood my explaination). I haven't changed them yet but I will soon.
lordcoleman 11-06-2008, 11:10 PM Hello, I have a '97 750. My bike idles at about 3k but I dont notice the hesitation when the bike first starts, only after a while when hot. When I try to accelerate in traffic, I feel it and it is very irritating. i have already balanced the carbs, tuned, changed the pilot settings to three turns and lower, but no changes. i dont know what to do now. Anyone with suggestions is greatly appreciated. For a 750, the bike feels underpowered. its very disapointing!
frekeyguy 11-07-2008, 05:04 AM Hello, I have a '97 750. My bike idles at about 3k but I dont notice the hesitation when the bike first starts, only after a while when hot. When I try to accelerate in traffic, I feel it and it is very irritating. i have already balanced the carbs, tuned, changed the pilot settings to three turns and lower, but no changes. i dont know what to do now. Anyone with suggestions is greatly appreciated. For a 750, the bike feels underpowered. its very disapointing!
Thats a very high idle. Check your idle screw adjustor knob.
If you feel that your bikes underpowered, best thing to do is, take it to a dyno shop, have them chart/tune those carbs for you.
Its a '97 750, those things are making about 110hp-112hp to the rear wheel.
markus2066 11-07-2008, 06:45 PM I have a very similar problem, do u have any mods?
Iv got a filter and exhaust, im goin to try altering the float heights tomorrow and see if that helps alall, ill let u know how it goes.
Mark
lordcoleman 11-10-2008, 04:30 PM Thanks for your reply. Boy, would really like to know if Kristo's adjustments to the manifold helped any. I have tightened my manifold screws and will test it by tomorow. i will let you guys know how it feels. i have a slight camber in the frame up front. the front wheel is IN a bit, its obvious to mechanics. I have a shudder when i get to 90mph. is the camber likley to be causing that, previous owner was in an accident. Is there anything that i can do outside of straigtening the frame-expensive.
lordcoleman 11-10-2008, 09:42 PM Ok, here is the verdict, I really can't say for sure if the tightening the manifold made a difference because my bike has been with the Police for 2 and a half weeks. i got it back scratched and it needed gas to start. I revs clean while standing, it sounds good. I didnt really notice hesitation on my way back from the station, feels alive! but I live a short distance so I wouldnt really notice it much. However, i do notice it now that I have ridden the bike some more (after a wash and some carb cleaner). What is happening now though is the bike is backfiring (after carb cleaner). i think it needs a good tune up, cleaning carbs, and it will be the best it has ever been!
lordcoleman 11-10-2008, 09:44 PM About the mods, i have a different Titanium muffler that came with the bike, its not stock, I wouldnt call it free flow though. I here it has oversized cams, what does that do? Outside of that, I think its pretty much stock.
SPL170db 11-10-2008, 09:45 PM It's a 600..........they don't have any lowend :D
lordcoleman 11-11-2008, 09:14 AM Nope its a 750 not 600, does that mean I have even more fear?
frekeyguy 11-11-2008, 09:20 AM clean your carbs and main jets...go from there...whats the miliage?
lordcoleman 11-11-2008, 06:47 PM The milerage "says" 38,000km. I had cleaned the carbs. i just called my mechanic, he said the go and stopy situation i am experiencing (since i got the bike from the police) is water in the fuel. The police actaully had my bike and a ton of others in the rain which has been frequent over the past two weeks. he says I need to drain the tank. ouside of that, re the initial hesitation I posted about, I think i can say with a degree of certainty that its gone. the bike feels like a 750 now. I have found a new respect for it. the starty stopy thing only occurs after a while of riding the bike a while. i guess that's when the water seperates and homogonises with the fuel. The initial 1-2 second hestation that has been plaguing me (i posted earlier about it) was caused, it seems, from a vacuum leak around the flange connecting carbs and engine head. i tightened that!
Special thanks to KRISTO. I'm out here in jamaica. Thanks for all the help genthlemen and ladies if there any!
lordcoleman 12-25-2008, 01:09 PM If any body is still intrested in this post. The gsxr 750 with hesitation problems. Well part of the problem was an intermittent electrical connection leading from the black box in the rear of bike. This caused the bike to lose power when i hit a pothole. The hesitation problem was in part because the manifold was not tight (vaccum leak) as described above. The also caused low power problems. I got a bottle of Amsoil Power foam and following instructions. Is sprayed it into the carb. Well it has improved dramatically, but the obstruction is still there and I have to keep redoing the spray job to improve it. Still working on it. I have already pulled down the carb and cleaned. No, no compressed air used yet, only chemicals.
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