| Author | Message | ||
     Riclyd |
Will there be difficulties and possibilities of damage to an XB12 engine by replacing the XB12 primary gearing setup with an XB9 setup? | ||
| 99buellx1 |
How would changing gearing damage an engine?  Check the thread that's about 10 posts down from this one called 'XB pulley ratios' (or something like that). | ||
| 99buellx1 |
Here: http://www.badweatherbikers.com/buell/messages/32777/231075.html?1159803177 | ||
| Fullpower |
direct bolt in. 10 percent more torque in every gear. | ||
| Asdf |
Howdy! I had my Ulysses Primary Ratio changed to the XB-9 (Sportster 883) ratio. For me it works great. The extra "Grunt" provided by the lower gearing is a "Perpetual Smile Generator". The new gearing is about 10.5% lower than the stock XB-12 gearing. This means that Engine Braking is also increased by about 10.5%. Driving in stop and go traffic is excellent with the lower ratio. Driving in town and in parades is a cinch, too. I will never miss the loss in top speed. I seldom miss the taller gearing while cruising, as I avoid main highways and slabs. With the lower gearing, 60 MPH = 3250 RPM, 70 MPH = 3800 RPM. Theoretical maximum speed, which on Buells is ultimately limited by the Rev Limiter, will be reduced from about 138 MPH to about 122 MPH. The XB-9 Motor Sprocket with Stator Cover assembly has 34 teeth. The XB-12 Sprocket has 38 teeth. The Clutch Sprocket for both the XB-12 and XB-9 has 57 teeth. Therefore, only the Motor Sprocket Assembly and the Primary Chain need to be replaced. The parts for the Primary Gearing change were about $195 USD. I could be off a bit, but that is pretty close. Motor Sprocket Assembly Part Number 32493-02 was $114, Primary Gasket Part Number 25352-00YA was $15.85 and the Primary Chain was about $65. DO get the Motor Sprocket ASSEMBLY that has the Stator Cover already riveted to it. Attempting to remove and then reinstall your current Stator Cover is not worth the time, money or likelihood of damage. Have fun! | ||
| Hogs |
My 12 revs at 3400-3500 at 60 mph. I find it revs to high for the highway cruising especially above 60 mph. Gets there really fast But have bounce off the rev. limiter alot more now, wd. rather go the other way now for Highway the 12 really doesn`t need the 9 setup especially If I go to the 90 inch kit what a waste that wd. be | ||
| Rootintootin |
The main possibility for damage is in an improperly adjusted (too tight) primary chain. If your primary is adjusted properly now, not making any odd noises or causing jerky shifting, take a good look at it, find out what is good up and down play, so you can duplicate it when you put it back together. The manual is vague and it seems there are more than a few favorite methods for doing this important step. You just have to get a feel for what is right. You can find lots of old threads about this here. Be sure to clean the threads on the crank and nut where you bolt on the engine sprocket VERY WELL. Use a liberal amount of RED locking compound and torque to the revised specs. On mine, there were 8 bolts holding the sprocket and rotor together, no rivets. It was a press fit, I did it on my bench vise. Lock those bolts too. The chain is a Sportster part, I bought it off the shelf at the local HD dealer. The sprocket was an order item. I had to drive a 140 mile round trip to order and do it again to pick up the item a week and a half later. I am now ordering my oem parts online from Daves. Great deal, and shipped to my location. Also, get the bar for locking the primary for disassembly and assembly. You need a larger than ordinary torque wrench for the revised 240-260 ft. lbs. of the engine sprocket. The first time I did mine, I maxed out my 150ft. lb. wrench and gave it a little extra oomph (a Harley mechanic trick) to hopefully get the 190-210 the manual calls for. I guess my hand isn't as calibrated as I thought it was, because that lasted about 2 weeks before it loosened up. You will definitely hear some nasty noises if and when that happens. Jim |
