| Author | Message | ||
     The4ork |
ok here is what i did, all in one shot... XB12 primary sprocket and went from open stock header, to force exhaust now anything under 3k, and mostly between 2k and 2.5k the bike bucks, stumbles, and then just picks up and hauls ass like usual grr! where should i start? bout ready to rip the force off, i have a ceramic coated stock header and just run it like that (its just as loud as the force, but sounds less ricer like) | ||
| The4ork |
oh also, it ran tits before i did those two things. | ||
| Bartimus |
The sprocket change would not effect your performance in this manner, the exhaust however will. Did you do a TPS reset after installing the exhaust? | ||
| The4ork |
no tps on my carb  | ||
| Buellistic |
Going to the XB12 motor sprocket alone will take away your low end torque ... Notice the RPM where your engine starts to haul ass and keep your RPM's there which is referred to as on the cam ... | ||
| The4ork |
 | ||
| The4ork |
guess i need more power  | ||
| Spiderman |
now anything under 3k, and mostly between 2k and 2.5k the bike bucks, stumbles, and then just picks up and hauls ass like usual Dyno tune... | ||
| Fahren |
Can you swap the exhaust back out with what you had, to try and isolate this as an exhaust issue? What's with all the header cracks in you profile? | ||
| Williep13 |
Do you have baffles in your Force? | ||
| Buellistic |
The4ork: Put the XB12 MOTOR SPROCKET and CHAIN on your wife's BLAST, it will make her happy'er ... She then gets more top end to keep up with your TUBE FRAME ... | ||
| Froggy |
You altered your motor, but did you re-tune it to adjust for these changes? Not that a good tune will make things perfect, but it sure will help. | ||
| Phelan |
Yes, dyno tune, so that you can get the ignition set right. On my old XL1200S, it used to stumble if I smacked the throttle in lower rpms. After the dyno tune @ NRHS, the stumble was gone . I had SE plugs, wires, ignition, and White bros exhaust on that bike and made 63 RWHP. They added a hurricaneflow A/C, rejet, and adjusted the timing and afterward the bike made 70 RWHP, with a much cleaner curve and without the torque dip the bike had previously. | ||
| The4ork |
the old header was cracked, and actually fell apart when i took it off... but i have another stock header i can use to isolate the problem. im jst worried about busting a stud taking the exh on and off all the time | ||
| Preybird1 |
I fixed my exhaust studs for good by taking the heads off and having them "up sized" To a huge 10mm grade 8.    | ||
| Ratbuell |
So let me get this straight...you went from an open header, to an actual exhaust with a muffler (and backpressure)...but didn't change jets? Re-jet. While the powerband is the only thing with a hole in it. | ||
| The4ork |
so your saying im running lean now? | ||
| Ratbuell |
Don't know without reading the plugs. My guess would be *rich* (IF, that is, you were mixed correctly before). Regardless, though...rich or lean, I'm willing to bet it ain't *right*. Put fresh plugs in. Go for a nice long-ish ride (20-30 minutes, all RPMs and throttle openings). Pull the plugs and read 'em and go from there. | ||
| Midnight_rider |
sounds like lean problem jetting needed | ||
| Kalali |
Isn't the flange supposed to be flush with the head? | ||
| Ratbuell |
My flanges never go tight to the head. Depends on the gasket being used, and how flattened it is (how many times its been reused). | ||
| Firemanjim |
The Force Exhaust is well known for having a big hole down low and did the XB gearing change your gearing for more high speed driving or opposite,because if you geared it up it will loose down low as a result. Open header????? Why?? Unless you have a drag bike, Buells need back pressure. | ||
| Phelan |
FMJ, the XB12 was for lower cruising RPMs, also higher top speed. RatBuell, the Force exhaust doesn't have a muffler; it had an open reverse cone megaphone. | ||
| Ratbuell |
Ya, and I probably used the wrong term...but the reverse-cone does the same thing a muffler does - adds backpressure. It's a "tuning aid" more than noise supression. | ||
| Firemanjim |
I rest my case--Force exhaust and changed gearing for LESS rpm. Will sure feel like less power down low. | ||
| Xl1200r |
Put fresh plugs in. Go for a nice long-ish ride (20-30 minutes, all RPMs and throttle openings). Pull the plugs and read 'em and go from there. It doesn't take that long to get a plug reading, and you should check at specific RPMs and throttle positions, not all at once. If it feel like crap down low, ride it up the street while it's acting up and hit the kill switch in the middle of it - then check the plugs. My guess is they will either look black, wet, or both. You sound rich to me, but not enough info to know for sure. | ||
| Maru |
The hole in your powerband is a result of reversion. The force exhaust makes big power on top at the expense of bottom end. If you run it on a dyno with a sniffer you will find that it is super rich during this flat zone. Jetting might help some but will not solve your problem. The gearing change you made amplified your problem. If you want the bike to run strong in the lower rpm ranges, you need a different exhaust. | ||
| Rlgiv |
I seemed to have a similiar problem at least with the stumbling issue when I switched to a D&D. Seemed to run rish in the lower rpms. a little tuning on ecmspy and now she runs pretty smoth in all rpms. | ||
| Maru |
The D&D's particularly, the full systems, do not have nearly the reversion issues that the force systems do. If you look at the TQ readings of the force systems it falls into a dip that is very noticeable. I have one and it is a great system for power but not at rpms that are often used on the street. As a general rule, longer primaries, the section of pipe before the collector, equals more low end power. The Buell pro series full systems seem to make good low end power. The less overlap the cam has, the less reversion issues show up as well. | ||
| The4ork |
Maru, are you saying the problem will worsen with larger cams (larger cams generally have more overlap, or so ive noticed on VW cams, im still new to HD engines) the more i use this force system, the more i dont like it. it may be perfect in other setups, but for mine the open small header screamed! i know i know, its an "open header" and should only used for "racing or drag bikes" but im telling you i *had* perfect low end and top end power. however, ill have to check what its like now with the re gearing. i might pop the exhaust off tomorrow and try my ceramic coated stock header and see. i already down a jet and the plugs went from light black to a dark brown, and the bucking is gone but it still has a large hole, which makes it a dog off the line in 1st until i get to about 10-15mph. until then its got about as much power as a blast LOL also keep in mind guys im running stg3 nrhs heads, and slightly shaved xb9 pistons (bigger valve reliefs cut in) maybe the extra flow and compression is why my engine liked the open header? | ||
| Tattoodnscrewd |
The Force pipe .... That is the root of your problems as FMJ stated. I can prove it if I can dig up my dyno results and 1/4 mile times... The Force pipe is horrible for low end grunt. And ALSO causes a loss when compared to other exhausts like the Buell race exhaust or the D&D full system in the higher RPM'S. Those saying the Force makes big power up top are only partially right, it does make more power up top than it does down low but it does not increase the power you get up top when compared to other exhausts. My 1/4 mile times were about 1/2 second faster running the Buell race exhaust (not tuned to that exhaust mind you) compared to the bike running tuned with the Force pipe. (My S1 had XB heads and 9 pistons at the time) The motor was built and dyno tuned with the Force pipe, that pipe broke at the dragstrip, the following week I ran with the Buell race exhaust - still with the bike tuned for the Force and ran quicker and faster. Most of your issue with low end loss is the Force .. however if you tune the bike to it it will be a touch better. | ||
| Maru |
Yes, the reversion issues with the force pipe get worse with more overlap. THE FORCE really tarts to shine up top with more overlap. The Buell race pipe, the full dand, and the kooks pipe all work good on a dyno. The Kooks has ground clearance issues. The Buell race pipe is the one I like the best. It has decent ground clearance, pulls clean down low, and has the bet noise control of the bunch. Steve | ||
| The4ork |
force pipe for sale!  | ||
| The4ork |
ceramic coated stock header is on, very little hole in the bottom end now  btw, dont touch the pipe even if its ceramic coated with your bare hand, even just to see if the ceramic coating works. it will burn you :/ |
