| Author | Message | ||
     Beeyoull |
Hi All, I just bought my first Buell today! 2005 XB12R. The bike is really great and pretty even tempered for a 1200cc. Here's my question: I've noticed that I can pretty much snap off the throttle (at RPMs up to 4-5k) and I only get relatively mild engine braking. Does this signal something could be wrong with the bike's compression? I traded up from a Ninja 250, and even that will display a good amount of braking if I downshift quickly (I've skidded the back tire by accident) although not much from simply rolling off. Even when downshifting the Buell (granted I try and be smooth with the clutch) I did not get what I would call "strong" engine braking. The bike has about 3,900 miles on it. Stock exhaust and everything else stock. What do you guys think? Thanks so much! Jon | ||
| Rogue_biker |
Buell designed the ECM to not allow the revs to fall rapidly when you close the throttle to facilitate smooth shifting. Also, the Thunderstorm engine has a heavy flywheel that allows the engine to have enough centrifugal mass to not spin down quickly. This type of tuning is only now finding its way into modern sportbikes. For example, the CBR1000RR's ECM is programmed to hold engine revs when the throttle is shut to help the rider make smoother downshifts or upshifts, as well as not upset the chassis during cornering if the rider decides to shift up or down. In the past, Japanese sportbikes used slipper clutches to achieve the same results. So I guess what I'm saying is, it is normal on your bike.  | ||
| Beeyoull |
Hey Rogue, Works for me! As long as nothing's wrong I can't complain - I was just worried that maybe the piston rings were shot (although the strength with which it pulls doesn't point to that - this thing is STRONG!) Thanks again - looking forward to lots of fun on the bike and good info from this forum (and hopefully being able to contribute back once I know more). Jon | ||
| Rogue_biker |
I meant the say that the slipper clutch is designed to slip during aggressive downshifts. This is done because on most of the Japanese bikes, when you shut the throttle, they quickly spin down. So when you do that then engage the clutch on the next lower gear, it's enough to make the rear wheel spin and upset the chassis. The answer is by keeping the revs up for a few seconds when the throttle is closed. I'm glad you're having fun with your Firebolt. I love mine. | ||
| Bombardier |
Kia does the same thing on their Rio as well. I thought the throttle was sticking the first time I drove it. | ||
| Djkaplan |
"Buell designed the ECM to not allow the revs to fall rapidly when you close the throttle to facilitate smooth shifting." The revs not falling between shifts actually makes the bike harder to shift smoothly when upshifting. This is one reason why all heavy flywheel bikes typically have a crunchy 1st to 2nd shift. You can confirm this yourself, btw. Experiment by letting the revs fall off slightly when making upshifts and you can easily feel the difference. This is also the reason why blipping the throttle when shifting down creates a smoother shift. When the lack of compression braking phenomenon started happening in automobiles, the reason was to pass stringent EPA regulations. When a throttle plate closes quickly, fuel mixture get richer (just for an instant) and creates a puff of pollutants. I assume now that EPA requirements are stricter for motorcycles, this ECM controlled strategy is now being employed by engineers to help pass the test. | ||
| Packrat |
So,going from a 250 ninja to a 1200 buell and you say it's strong ??  |
