A few weeks ago I took a roadtrip. On the way home I stopped for gas at a poe-dunk gas station. About 10 miles after filling up when coming up on a redlight I pulled in my clutch and heard the sound for the first time, which sounded like a spitting sound or even a spark plug missfiring. As I pulled up to the red light I looked at my tach and noticed that my idle rpm's had dropped from a normal 1400 to about 1000. I pulled into a parking lot and while coasting to a stop the engine just cut off. I gave it a few minutes, started the bike back up, and headed home.
My first thought...BAD GAS. So after I got home I siphoned out 4 gallons from my tank. Mind you, I only put in about 3.3 gallons at that gas station. I went up to the gas station and put in a couple gallons of regular. Went home, pulled the spark plugs which were slightly fouled. I replaced those...and still no change in performance. Everyone I talk to thinks it's bad gas, but since filling up I have put almost 400 miles on the bike...with no change in performance.
I have added Heet, which is known to remove water from a tank if there was any water in it from the gas...with no change in performance. I added Seafoam, which cleans carbs...with no change in performance.
I found a similar thread which the member solved his problem. This thread was about 50 pages into this forum. But, there was no description of how he fixed the problem. His problem had something to do with a air leak into the carbs I guess.
I just went over 2000 miles on this bike, and bought this bike (2007 GS500F) with 509 miles on it after I was rear ended on my ninja while sitting at a red light. I loved my Ninja, and love my GS, but the spitting sound, squealing back brake, and fact that I'm sputtering out at lights and have a spitting/missing sound when idleing and when shifting gears too is getting really annoying. I've come to the conclusion...it's not BAD GAS.
Please help!!!!!
Basics kiddo ... same all the time.
Clean carbs, clean air filter and rejet if needed. Look for air leaks from intake side and exhaust leaks and check for rust in the tank.
Intake leak is wd40 spray and look for rpm's to shoot up and smoky exhaust.
Exhaust side is a gentle hand feel - BTW tighten the thing up before you start it.
Then of course the harder stuff, clean the carbs - though on a regular runner it could be less likely.
Check and clean air filter ...
Oh one more thing - if the thing is due for a valve adjustment - was it done @509 miles - it should have been, but then you may be OK till the 4K mark, but if now, check it now.
And while you are in there, re torque the head bolts.
Cool.
Buddha.
Well, carbs aren't a worry. I've had a bike with dirty carbs before (1982 Kawasaki CSR 650) and never caused it to have a spitting sound.
I took the plastics on the left (when riding) side off and the spitting sound is coming from what looks like the block just to the right and up of the spark plug. This is my first suzuki as I have always had Kawasakis, so engine placement on certain things is a bit different...kinda feel like I don't know exactly what I'm looking at.
Tank is clean as a whistle, so no rust problems there.
Never had an intake leak to check, so I am assuming that I spray wd-40 on the 1 1/2" diamater black tubes going from the block to the carbs. If not...where am I supposed to be spraying?
"BTW tighten the thing up before you start it."
What do you mean? I've never heard this term. Again, sorry for my ignorance on this.
"Oh one more thing - if the thing is due for a valve adjustment - was it done @509 miles - it should have been, but then you may be OK till the 4K mark, but if now, check it now."
Got the bike from a dealearship. The said they gave it a 100% tuning when they got it in 3 weeks before selling it to me. The first 2 weeks I had it I blew out a little bit of carbon from the exhaust which I was expecting to do since I got it on April 28th with 509 miles on it and I am over 2000 miles now. So, it's a regular ride for me as I commute to work every day there isn't water falling out of the sky. It ran like a charm all of May and first 2 weeks of June and then this happened all of a sudden with no warnings or sputtering at all.
kind of sounds like backfiring. lots of things could cause backfiring. give the ignition system a good check, and make sure your rotor (under the right circular cover) is tight and on the index pin. mine came loose once and backfired miserably before dieing completly... on the highway.
also, I've heard some air cooled bikes can misfire or backfire on high octane gas, but not regular (seriously, i dont know why, so take that one with a grain of salt)... if you pumped her full of the good juice to "clean it out" this may cause some of your problems as well.
...or the valves could be shot, or it may not be backfiring at all.
I agree with Buddha. Check for an intake or exhaust leak.
spray WD-40 on the carb boots between the carb and the head. The idea is if a leak is inhaling air (and leaning out the mixture downstream of the carbs) then it will suck in some WD-40 and run faster (more "fuel" in the mix). So if spraying WD-40 causes the engine speed to increase, then you've found an intake leak.
Exhaust leak (usually where the header joins the exhaust port) could be because one of the two bolts on either pipe has backed out due to vibration (has happened to me) or was overtightened and snapped from heat expansion. Either way, try backing out the bolts and retightening them. New exhaust seals (aluminium crush washers) are just a few cents each. Why not loosen the headers, replace the seals, and retorque (and do it to the right spec -- check the wiki -- 'cause too tight will cause them to break when the engine heats).
Start with those diagnostics, and then report back.
Since the bike is so new with almost no miles on it, I'm thinking you have wet ignition (since it's been raining so much) or a loose plug wire, something along those lines. Spray the rotor and ignition pick-up (under the round right cover, 3 screws) with some WD-40 and see if that helps. This problem smells electrical to me, and you don't need a valve check for several thousand more miles, and that's just a check. There are members on this board who check their valves every 4,000 miles or so and find they don't need to actually change a shim for 20,000 miles. I don't think it's a loose vacuum hose because that will make your idle rise, not fall.
So here is what I have done to it so far and what I have found out...or not found out. :dunno_white:
I checked for vaccum leaks all around and got nothing. Sprayed with WD-40 and carb cleaner and no spikes of rpms and no white smoke at all. :dunno_black:
I have checked all wires for a 2nd time...and then a 3rd, and nothing is loose. :thumb:
Took the tank off and checked the air filter...just to see. Damn thing is clean as a whistle. :cheers:
Checked the fuel lines to see if anything was crimped since what is happening almost seems like the bike is being starved for gas. Nope. :D
So, I played with the idle screw. Got my idle rpm back up to around 1500, which has stopped the sputtering. There is still a very spuratic spitting sound coming from where the spark plug is on the intake side of the bike...but it is to the right/rear of the plug... :icon_idea:
Bike is not stalling out like it was, but has stalled out a few times at lights when sitting there with the clutch pulled in for more than 2 or 3 minutes. But, when in neutral she purrs like she was brand new. After playing with the idle screw the performance is back in the bike when I give her some throttle on the open road, and when in neutral she screams like she did before now with throttle, also when taking my hand off the throttle when riding she doesn't seem to want to slow as much or lurch like she did before any of this happened a few weeks ago.
I know the problem isn't totally fixed, but for now I have delayed the inevitable of taking her into the shop. :2guns:
You check for an exhaust leak.
Cool.
Buddha.
Well what was the outcome of this? I guess I have been very fortunate I have never experienced anything like this? Seems awfully weird like maybe you got some junk in the intake system. When you took out the gas was it clean? Did it smell funny?
I assume it doesn't have an inline fuel filter? Just the in-tank screen?
If it doesn't (stock configuration) I bet you have a slightly plugged jet.