| Author | Message | ||
     Impulse_101 |
My 1997 S3T is running very rough lately when I start it up until I get at least 10 miles from the house. I usually warm it up for around 5 to 10 minutes before a ride and it's really coughing and backfiring during the warmup period in the driveway. Once I'm on the road it will cough until I hit 3500 rpm and even then it will hickup a bit when trying to run it steady. It will smooth out a bit if I pull the choke while I'm riding but it slides back in a few seconds due to the vibration of the engine. I just changed the oil and the engine is smoother once it is warmed up, but the first couple of miles really suck! The bike usually runs smoother than this. I've put 10000 miles on it so I've gotten to know the way it feels normally and this is definetly different and it's only been running this way for the last two weeks. Should I start thinking about the plugs, or running the carb a bit richer? JT | ||
| BadS1 |
John check for a intake leak.Warm it up then while idling spray some WD-40 around the intake.If it leaks the bike will cough a bit. | ||
| Bomber |
EZ stuff first -- plugs (specailly if you've not changed em in 10K miles) -- plug wires (ditto if original) jets don't wear, as a general rule -- if it was OK b4, I'm bettin iginition, and the cheapest place to start is plug and wires | ||
| Impulse_101 |
Dana, Do you mean that I should spray it around the gasket on the forcewinder? Bomber, I'll check both tonight. They're an easy fix. Thanks guys, JT | ||
| Bomber |
Imp -- Dana's referring to the seals between the intake manifold and the heads -- also check the seal between the carb and manifold, same process | ||
| Tramp |
Did you say "forcewinder"???? how long have you been running that on it? that could be the problem.... | ||
| BadS1 |
Tramp Forcewinder is not the problem.Its been on that bike for along time.Like in years. | ||
| 98cyclone |
Try blowing out the vent tube, one of the things Dana told me to try when mine was running bad. Witch you may have done, just a thought. | ||
| BadS1 |
That Kelly I doubt is his problem. | ||
| Tramp |
i would bet it's intake seals. change 'em even only as a matter of course. you kmnow- the ones betwixt your heads and the manifold. classic symptoms of a classic problem | ||
| Jammer |
Make sure the idle mixture screw hasn't fallen out. clean the slow and fast jet and emulsion tube it's been my experience that they get a coat of varnish on them after a few weeks in the garage and it starts to run lean. Even if I drain the float bowl. Thats my 2cents good luck. Jeff | ||
| Rippin |
Jammer I must concur! Fuel these days does not bode well with time. Maximum fuel life is 30 days or less before it starts breaking down. Pilot jets plug very easily also the small orifices in the needle jet (long tube under main jet)clog easily. Dana Also sounds like symptoms of intake leaking. Had problem on my '99 using cheap seals after top end rebuild, Had'm go bad on my '01 within the first 500 miles of being new. I would definitely start simple and work my way forward. Ryan | ||
| Impulse_101 |
I took a look at the intake seals before I left work today. I'll do the WD-40 inspection tomorrow. I'm going to replace the plugs and wires and then the intake seals if needed. I've never rebuilt a carb but there's no time like the present to learn. I'm pretty sure that the carb is clean. I ride 60-70 miles a day and I go through two tanks of gas a week. (approx) Thanks for the help guys. JT (Thank goodness for badweb and that I bought the repair manual) (Message edited by Impulse_101 on June 15, 2005) | ||
| Bomber |
classic t'shooting has you starting with the simplest/cheapest attempts, and moving to the more complex/expensive as you eliminate possible causes . . . . . this from the guy that rebuilt his carbs under a bridge, in the rain, at night, to attepmpt to clear a problem caused by an empty gas tank -- needless to say, it didn't work gas DOES go bad very quickly these days, and the pilot jet does clog easily, no doubt -- if the scoot was running well at homecoming (as I assume, dangerous, that), I doubt if the jet has clogged, especially in light of the miles put on weekly and the gas run through it (although a tank of really wretched fule could, I suppose, cause an engine with an iffy system to get worse) when my idle mixture screw went walk-about a few years ago, it sounded horrible at low rpms no matter how hot or cold the engine was -- horrible backfiring (not that nice burble we all love), and snatchy low rpm operation (which makes good sense, of course) . . . . I'm bettin on plugs, wires, and a seal in the intake tract, in that order ain't long distance diagnosis fun? Doktor, my leg hurts, whats wrong? ;-} | ||
| Tramp |
i'm betting on the reverse. plugs and wires are good for a bit longer than intake seals. i change 'em as a matter of course. i'm all about new wires and plugs, and absolutley agree they should be changed, but the likely culprit, based on the 'usual suspects', is gonna be the seals. 'specially being it's more of a 'warm-up' issue, as opposed to a constant symptom. plugs and wires are cheap enough, and keihins are a joke to 'rebuild', so it won't hurt to do 'all of the above'. don't ever rule out exhaust leaks, even those interfacing the header and muffler can cause these exact symptoms. while it's certainly fun and innerestin' to point out the 'techier' fuel-quality related potential culprits, remember the frequency of intake seal and exhaust leak issues. sometimes diagnostics are more a question of democracy than technocracy  | ||
| Ara |
I had the same problem. Pull the breadbox cover off and check the three allen-head screws around the carb throat that seal the inner cover of the breadbox to the carb. If they're loose, snug them down, put the cover back on, and then go for a test ride. | ||
| BadS1 |
He doesn't have he bread box.He's got a Force winder. | ||
| Impulse_101 |
I sprayed the intake seals down and it didn't cough at all. I'm starting to think that the culprit was a couple of tanks of bad gas. Probably one of those stores where they fill the premium tank with regular. I know that it happens in Milwaukee, we did a story on it at the TV station. I'm going to replace the plugs anyway and the wires as well. I talked to Dave and he said to go with the stock Buell parts so that's what I've decided to do. JT | ||
| Koz5150 |
I have the forcewinder on my M2 and my bike was doing the same thing. I took it in for a Dyno Tune-up at Appleton HD (and made the forcewinder mods listed in the knowledge vault). It runs SOOOOO much better now. The dyno time was $65/hr and they ended up rejetting my carb, but in the end I got 11 more hp out of the bike! Something to think about. | ||
| Impulse_101 |
The problem went away for a few days and today it was back with a vengence, so I did the WD-40 test again and the engine took off like a rocket. In fact it kept running after I killed the engine. WD-40 must be pretty high octane stuff! Daves is going to drop off a new set of seals tommorow on his way through Racine. (Yes, Dave is the man!) I need to have the bike up and running by this weekend since I'm down a truck right now. The instructions in the service manual are pretty useless for the this task so I'll have to figure it out on the fly. Hopefully I won't screw it up too bad. JT | ||
| Tramp |
yep!  | ||
| Bomber |
Yo, Imp -- it's easy, just go slow and pay attention (tough with a little one in the house, I know) | ||
| Impulse_101 |
Here's the big question. Do I need to pull the gas tank? Dave and I discussed it and he thinks that I should but neither of us have ever done it. Bomber, I will have complete concentration. The baby will be asleep or in Becki's capable arms. JT | ||
| Iamike |
JT- It's pretty easy to remove the intake. The manual says to use a ball-end allen wrench. If the bolts are tight you may need to cut off about a 3/8" section of one, just long enough to fit in the bolt and box wrench at the same time to get the torque you need to break it loose. On re-install just go slow and even as you tighten things back up. My F.I. ran like crap when it was cold, for 3 years and 30,000mi. Three different dealers told me that's the way they all run. When I changed my intake seals I found a cap off of the throttle body evap tube (if mine was a California model) was missing. It's amazing what a difference that made. | ||
| BadS1 |
Impulse yes remove the tank.It's only one bolt.Then you can look right down at your intake. | ||
| Tramp |
if removing the s3 tank is a task that causes any trepidation at all, don't change your own seals | ||
| Bomber |
Imp -- may be possible to drop the intake w/out removing the tank, but you'd need an extra elbow and wrist, both -- since you've got a carb'd scoot, removing the tank is a piece of cake, 10 mikes with a beer break the manual's pretty clear on this, but . . . . (from memory) 1. remove tank 2. remove air cleaner 3. remove carb (it's ok to leave the poor dear attached to the throttle cables and let it dangle, gently (don't forget to unhook the choke cable from the other side of the bike, otherwise the carb won't move very far -- easy to miss sitting on the carb side) 4. remove intake manifold 5. throw old seals away 6. go inside, wash hands, kiss wife and baby 7. grab new seals 8. perform steps 1 - 4 in reverse order 9. Lather 10. Rinse 11. Repeat everybody's gotta start somewhere, and this is a great scary lookin but relatively easy task to build wrench-confidence | ||
| Tramp |
i agree. my point is, however, that if anyone finds removing one bolt and a fuel line clamp daunting, then, really, they should leave intake manifold R&R (which is, obviously, a breeze) to a professional. | ||
| Impulse_101 |
I get the point. Draining the tank may be the hardest part of removing it. Bomber, I'll let the carb dangle from a zip tie, or similar support to save some time. I'll let you know how it goes. JT (Message edited by Impulse_101 on June 24, 2005) | ||
| Bomber |
no need to drain, brother -- just find a good place to put it |
