Speed99 Posted April 15, 2003 Share Posted April 15, 2003 I have a throttle response question. Between OFF and 1/8 throttle, it seems like there is a delay and then she comes to life with a little snap. It is like there is play in that first part of the wrist twist. It can be a little scary on low speed corners when I try to give a small amount of throttle input...there is nothing there....then it snaps on. Is this normal.....do I need to clarify more. I am hoping there is a non-PCII fix for this so I don't start another Holy War. Thoughts? If there is another post covering this very problem....let me know and we can scrap this one. Thanks, Rick EDITTED: I have a '99 (Injected)....5600 miles Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 15, 2003 Share Posted April 15, 2003 Try looking at adjusting the throttle cables. Sounds like they're a bit loose. Normally just a lock nut and then finger tightened thread that adjusts the cable. IIRC the XX setup is a twin cable, so you want to check on the cable that opens when you twist the throttle open as the target for adjustment. Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 15, 2003 Share Posted April 15, 2003 Yeah, all the FI models have this problem. Caused by a lean spot. Richening the mix helps it some, but it doesn't go away completely. Quote Link to comment Share on other sites More sharing options...
GerardoXX Posted April 15, 2003 Share Posted April 15, 2003 :evil: That behavior is normal in the FI model, the PC commander solve pretty much this problem. :twisted: Quote Link to comment Share on other sites More sharing options...
spEEdfrEEk Posted April 15, 2003 Share Posted April 15, 2003 Happens, to some degree, on most bikes with CV carbs (judging from what I can gather). It's certainly nothing I'd experienced on MX bikes with direct cable-to-slide carbs.. :cool: TJ :cool: Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 15, 2003 Share Posted April 15, 2003 I have not tried it with the PC. With the Techlusion TFI box, which affects ALL throttle positions and speeds, it was better. I'd characterize it as "half gone," along with the 5300 RPM flat spot which was nearly gone. Unfortunately, Techlusion was never able to solve the problem of the too-smart FI on the XX. The bike sees the injectors staying open longer than they should, and generates an FI fault eventually. Quote Link to comment Share on other sites More sharing options...
slowxx Posted April 15, 2003 Share Posted April 15, 2003 You can change you PC yourself from 0 to 11,000rpm. It can make it run real good or real bad. Try setting your idle past the lean spot about 2,000rpm or so, that will help. :roll: I also helps low idle oil pressure. Quote Link to comment Share on other sites More sharing options...
XX RATED Posted April 15, 2003 Share Posted April 15, 2003 I adjusted my throttle cables with the top cable (throttle open) having no play [0] - Honda recomends 1/8' play (I believe) but I like it tight. I set the idle @ 1100 rpms. With the throttle set as above, the PC-II & the Mig pipes, I have absolutly no flat spot at all! No exageration - gospel - I swear! Quote Link to comment Share on other sites More sharing options...
Obby Posted April 15, 2003 Share Posted April 15, 2003 I've have the 1/8 throttle delay issue too. It's right when i just begin to open open throttle...then surging power ('97 carb cal. model with dyno jet kit and dual micron exhaust). It wouldn't be such a big deal if the big bird didn't have so much torque. Quote Link to comment Share on other sites More sharing options...
tvking Posted April 15, 2003 Share Posted April 15, 2003 I have the same problem. With the larger rear sprocket it's even worse. Just getting around an intersection in 1st gear can be more exciting than I'd like. Quote Link to comment Share on other sites More sharing options...
bbirdxx2000 Posted April 16, 2003 Share Posted April 16, 2003 Not to start a war but :cool: , I saved hudreds of dollars by have my Injectors (throttle boddies) synked while putting in a K & N at the same time. Problem solved :grin: , even got better gas mileage, best being 43 MPG, low fuel light went on at 210 miles :grin: Harry Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 16, 2003 Share Posted April 16, 2003 TB sync (or lack of) doesn't cause this problem. It causes surging at steady throttle and hunting at idle. If you didn't have those problems, sync did nothing. I've checked the sync (which Honda says should NEVER be adjusted, BTW) and it is perfect. Yet the off-idle problem persists, of course, since it is unrelated to sync. Who did this unnecessary work, and where did they get the service procedure since there isn't one? Quote Link to comment Share on other sites More sharing options...
bbirdxx2000 Posted April 16, 2003 Share Posted April 16, 2003 My local shop, All I can tell you is that it made a slight differance, maybe combination with the K & N filter :cool: Harry Quote Link to comment Share on other sites More sharing options...
Speed99 Posted April 16, 2003 Author Share Posted April 16, 2003 <Hanging out and reading your responses.> I will try adjusting the cable first and see if that helps. Richening the mix helps it some, but it doesn't go away completely. How do I do this on the Bird? I have the Haynes manual, but not sure if it will tell me how to do it. -Rick Quote Link to comment Share on other sites More sharing options...
Andy1100 Posted April 16, 2003 Share Posted April 16, 2003 Make sure the throttle cable is adjusted up, and make sure your chain is adjusted up too. That little bit of excess driveline slop can make a difference too! Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted April 16, 2003 Share Posted April 16, 2003 Hey Swampy, I've got a carb. model of course. Why don't FI throttle bodies need Synced. Carbs and FI both have 4 throttle plates hooked up mechanically. both subject to going out of sync. from wear/vibration and individual cylinder vacuum diffs. Just want to understand. Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 16, 2003 Share Posted April 16, 2003 EFI systems can still be sync'd - ask anyone with an EFI v-twin like the RC51 or Mille. The sync is used to control the timing minutely of the fuel delivery at the injector level rather than the EFI. Over time the sensors do get dirty or just loose adjustment so you end up bringing them back to the right value. It's much more important in a big twin than an I-4. And, to the others - on my bike I only get the off-throttle jerkiness while the bike is still cold. Once it's warmed up it's smooth as anything so I definitely think the problem is throttle cable or loose chain. Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 16, 2003 Share Posted April 16, 2003 Why don't FI throttle bodies need Synced. That's what Honda says, I don't know what they did that's so special. The screws are even sealed from the factory. The dealer manuals say "no service" and there are no TSB's on doing it. I measured vacuum on mine at around 40k miles and it was perfectly even. I have yet to ride a XX that does not have this problem. You can minimize it with tight cables, tight chain, and a slightly higher idle, but it is there. I've had this argument a few times--guys swear THEIR bike doesn't do it, but it does. Quote Link to comment Share on other sites More sharing options...
Andy1100 Posted April 16, 2003 Share Posted April 16, 2003 Mine definately does it, but it has helped me keep better control of it to have the trottle cable less than 1/8 in of play, and to stay on top of the chain, keep it within specs.... Quote Link to comment Share on other sites More sharing options...
mickcbr1100 Posted April 16, 2003 Share Posted April 16, 2003 Mith is correct in saying EFI systems can still be sync'd - ask anyone with an EFI v-twin like the RC51 or Mille. The sync is used to control the timing minutely of the fuel delivery at the injector level rather than the EFI. Over time the sensors do get dirty or just loose adjustment so you end up bringing them back to the right value. It's much more important in a big twin than an I-4. Â And, to the others - on my bike I only get the off-throttle jerkiness while the bike is still cold. Once it's warmed up it's smooth as anything so I definitely think the problem is throttle cable or loose chain. The Haynes manual does give the correct procedure for synchronising the FI starter valves stating "out of synch starter valves cause uneven idling when cold starting and warming the engine" which seems to cover the point raised by a few with FI when cold. It isnt too hard a job I use the Morgan carbtune manometer not found much of a variation but just do it for peace of mind. Quote Link to comment Share on other sites More sharing options...
tomek Posted April 16, 2003 Share Posted April 16, 2003 FI on XX is a single throttle system and as such on/off throttle response will be questionable and jerky.It can be tune out to some degree by dumping more fuel ( richening ) in offending area of rpm/ % of throttle opening to make engine come on power softer but I don`t think it can be removed completely. I understand that Yamaha`s and Suzuki`s dual throttle systems are much better in this regard.First gen FI Gixxer 750 had single throttle and had the same problem,later they "invented" second throttle just to cure it. I really like Yamaha`s FI on new r1/r6 models,very simple and it works. Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 17, 2003 Share Posted April 17, 2003 for synchronising the FI starter valves But that's not what we're talking about. We're talking about synchronizing the throttle body butterfly valves. Totally different. The starter valves are out of play once the bike warms up even just a little bit. Quote Link to comment Share on other sites More sharing options...
skybluebird Posted April 17, 2003 Share Posted April 17, 2003 Maybe it's an ignition mapping thing (for emissions?). My (UK) bike has absolutely no delay whatsoever. My dirt bike has this problem and I bleeding hate it, but the Bird's throttle response just couldn't be any better. Should be possible to adjust it out, then. David Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 17, 2003 Share Posted April 17, 2003 It is an emissions-related lean fuel condition. Quote Link to comment Share on other sites More sharing options...
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