:( Please guys, I need help. I'm not all that new to riding but am probably still considered a newbie when compared to most of you. This is my first 600-class bike - its a 99 R6 that has been race tuned, jetted, HEAVILY modded (internally and externally, all before I bought it), but has fewer than 10000 miles. This is my first riding season on this bike and Ive run into a problem. Until yesterday (April 06, 2005), my bike ran finely, but then it started sputtering and throttle response dropped to almost nothing. The bike wouldn't go more that 5mph and rpms wont go above 400-500! Occasionally (every ten mins or so) I could get one good rev at fairly normal throttle response, but then, if I let it idle, the engine died and the problem started all over again. At first, I thought I'd run out of gas so I VERY slowly (5mph) rode the bike the 1/2 mile home and filled it up, but the problem is still occurring. I dont know what to do. My ex-(diesel engine)-mechanic dad suggested that this might be related to the fact that the bike has been in storage until now and that gas additive etc is still in the lines. He also suggested that whatever fuel was in the bike all winter long was dirty, or that I needed a new fuel filter. I don't currently have the money to take it to the shop ( 'cause I'm going to Russia in two weeks) so Im really in a lurch. Any help that you can give would be much appreciated. :(

-Sorry for the long post!

Ok there are a few things to try

- Drain ALL the gas from the tank and lines

No matter what that will be more good than bad.
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If you are familar with taking a carb apart do the following
-Remove and clean Jets / open ports to the carb
-Remove all plastic and rubber from the carb, Dip in carb cleaner or special carb acid, and let sit for recomended amount of time. If no time specified try 12 hrs.
-Remove, rinse, and use air nozzle to blow dry REALLY WELL
-Let sit for 24 hrs to confirm its dry
-Reassemble, spray some starting fluid in the carb just prior to connecting fuel line (Helps remove any mositure and fire the motor and get gas going)
- Try starting and tuning the carb again, this will probally take some time and patientence. Most gas motors i worked on there are 2 screws on the carb, one for throttle controll, and another for mixture. it takes a while to get it going, but if you count how many rotations it takes to remove the screw's then getting it back will get you very close and a lot less screwing around, more just a fine tuning
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If you are NOT familar with taking a carb apart, or really dont want to mess with it try the following

-Spray some carb cleaner in the carb, clean what you can openly, pipe cleaners and toothbrushes work excellent and are cheap
- Put a couple good shots of starting fluid in the carb, reconnect the fuel line, and get an super concentrated bottle of carb / fuel injector cleaner. Usally a good basic fix if there is some buildup in the carb. Mix that with the gas as recomended and try firing it up with fresh 93 octane gas
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Other things to think about, are the mixtures on the bike right? If they are off, they wont work or will make the bike do what its doing.

But im sure fieronk is the person to field this problem, since he has a bike just like this and knows his stuff

Okay thanks for the intro.

What has happened is common with small engines. (And by small meaning the size of the parts not the performance.) The gas that was stored in the bike and in the carbs has turned to varnish. It's really not a big problem, just a huge pain in the @$$.

Question: Was this the original tank of gas that sat in the bike all winter? And you hadn't added any clean gas while you were riding on the 6th?

Draining the gas out of that tank is a good start. Chances are the gas turned on you and as you rode, all the sludge started to build in the carbs and then when you left it over night the sludge set-up camp and doesn't want to leave.

Personally I wouldn't recommend using carb cleaner or anything that is a fuel additive. What they usually do is they're made of alcohol and dissolve the gunk. But once all that alcohol gets into the motor it burns very hot and is not very friendly with race prepped aluminum motors. :wink:

Like Fire said, your going to need to clean the carbs. I doubt they'll need readjusted, just cleaned out. If you feel comfortable pulling the bank of carbs yourself thats great. It's not really hard just a little time consuming. And I'm pretty sure you'll be able to keep the carbs together so you won't have to synch them after wards.

Cleaning the carbs in a nutshell: Once you get the bank of carbs off, the one side of all the carbs will have a big round plastic cover with 4 screws. Take the screws out and then lift out the diaphragm and clean all the little passageways. (Do this one at a time so if you forget how it goes back together you can take the next one apart and compare.) Reassemble, and flip the carbs over and take off the cover on the back. Again clean all the grooves and passages. Reassemble. Reinstall on your bike.

Thanks a lot guys - you've been a lot of help. Im not the greatest with engines so manually removing and cleaning the carbs, for me is a job best left to professionals, or at least someone whos a bit better acquainted with small engine maintainence until i get my bearings in this type of work. luckily i have a friend who is a small engine mechanic so im sure he'll help me out. - anyway, ill definitely take your advice. ill clean the carbs, replace the fuel, etc... - ill use 93 octane like you said (i'd been using 87). thanks again.

-ted.

Yea never ever use 87 in a motorcycle espically one that revs high and gets really hot. Just wont perform like it should, probally get pre detenition

thanks for your help guys but it didnt really work. i gave in and took it to the shop. they drained the fuel, cleaned the carbs, and replaced the fuel filter. i took the bike home and it started right up and ran just fine, but the next morning (no, it wasnt cold) the bike wouldnt start.ive tried everything that i could think of to fix it (which probably wasnt much since im fairly new to this), but im out of ideas. - please help! :cry: :cry: :cry:

take out the spark plugs, see if they are cleaned or fouled, bring them down to the shop and see if they are gapped right or if things are off, maybe check the wires too, make sure they are not cut or damaged or worn at all cause any little bit does screw it up. I would start with that, im guessing right now there is something wrong with the firing sequence, check the manual on the yahama site and make sure that plug wires are in the right sequence plugged in

Now you said that you checked everything you could think of, what did you check?

Basically something had to go bad from the time you rode home until the next morning. Maybe some crap or water fouled up the fuel filter. These bikes have a paper element under the tank that get really blocked up if the absorb any water. You can check this by lifting the tank, turn of the fuel vavle, and pulling out the fuel filter, then try to blow through and see what kind of luck you have. You may want to replace it for good measure.

Next, does the bike turn over or is it completely dead? If it turns over but didn't start at first, there's a high likely-hood that the motor full of gas (not a good thing). So you may want to pull the plugs and smell them to see if they STINK like gas. If they are wet and stink, you need to let the motor dry or it will never start and you'll wash the cylinder walls (also not a good thing)

If they don't stink you need to check to see if you're getting spark. Your coil or ecu or module could have gone bad. The easiest way to test this if you aren't very mechanically inclined is to get a spark tester from like pepboys, and then set it to less spark then what the coils put out. You'll have to check with a dealer, I don't know what thier output is off-hand. And see if you are getting good spark at each plug.

Also just check all of you fuses, any wiring harness connections you can see (give them a little push back together) Now you said this was a '99. Have you tried to push start it? Sometimes all it takes is a little motion to get the gremlins out.

Give another update if this helps or not. We'll get you wheeling soon enough.