| Author | Message | ||
     Skifastbadly |
Here's what my pistons look like....  | ||
| Hughlysses |
Mine looked almost exactly like that. | ||
| Johnboy777 |
Hey Skifastbadly Is the left the rear - or vice versa? John | ||
| Skifastbadly |
John, I can't answer that, I didn't do the disassembly, but I sure wish I had. HD service took it apart, told me how much damage there was, and quoted me a price to fix which I passed on. Then they gave me a nice big bill for the time and brought the parts back in a box. | ||
| Hughlysses |
I haven't had time to do any further teardown on the bike yet; I've been trying to get my motorcycle gear/tool room straightened up as it's going to have to house all these take-off parts in an orderly fashion until I can put the Uly back together. I'm making good progress on that. So far I've found three places that can repair my crank: Revtech, Johnson Engineering, and Darkhorse. Darkhorse says the 08 crank upgrade significantly improves reliability of the bearings that failed on mine and it would only run $25 more than repair of the stocker, so I'm heavily leaning that way. Next major decision is the cylinders. HD doesn't sell just the pistons (only cylinder/piston/ring sets); aftermarket pistons are ~2/3 the cost of new OEM cylinder sets, and I may find my cylinders can't be over-bored enough to remove the scratches. The aftermarket 1250 barrels and pistons would be 1.5 to 2 times the cost of OEM cylinders. Seems like a lot of money to pay for 50cc, but there may be some improvement in quality of the parts as well. I'm still watching ebay for used engines, and I did e-mail one motorcycle junkyard in SC who quoted me $2100 for an 06 Uly engine. That's in line with most of the ebay prices, but it still looks like I can do a better-than-stock rebuild on mine for about the same money. Hopefully disassembly/engine removal will resume tomorrow. I'll post more photos as I proceed. | ||
| Xbimmer |
Darkhorse says the 08 crank upgrade significantly improves reliability of the bearings that failed on mine and it would only run $25 more than repair of the stocker... Pleading ignorance, is that only a bearing change? IIRC the rotor and oil pump drive changed also in '08. Good luck on your fix, has to be a bummer. | ||
| Hughlysses |
The 08 crank has a 1-1/2" diameter crankpin vs. 1-1/4" on pre-08 XB's, with larger bearings to suit. Just like increasing the size of the rear wheel bearings, they will withstand more load without failing. The 08-up engines do have a different oil pump and larger oil cooler, but they also have a higher redline RPM. Apparently quite a few of these conversions have been done on 02-07 XB race bikes and are pretty well proven, so the old-style oil pump must be adequate even with the larger crankpin bearings. | ||
| Xbimmer |
Guess I should've been more clear, what I meant to ask was whether your wormgear-drive oil pump will still work, and your alternator rotor also. IIRC those changed in '08, but maybe I'm wrong. Doesn't the '08-up primary gear/alternator fasten with a bolt instead of a nut? Still wondering and interested. | ||
| Hughlysses |
I know that the crank will handle the old-style oil pump drive gear Ok & that you have to install an 08 primary sprocket. Hopefully the 07 alternator rotor can be pressed on the 08 sprocket. | ||
| Mnrider |
I had a crank bearing go on my 1985 Ski-doo MX snowmobile,that was a Rotax 2 stroke so all the bearing pieces went up and smashed the piston and the rod broke the cyl. sleeve. Had it sleeved and the crank repaired and bored and new pistons. I couple years later the other crank bearing went out so I had to do it again. Two strokes are easier to overhaul so it wasn't too big of deal just $ for parts. If they can do the 08 bearings and rods that would be a good upgrade. Good luck,sounds like it will work out OK. | ||
| Xbimmer |
OK Hugh, thanks! | ||
| Teeps |
The larger main bearing sounds like a win/win if it's not cost prohibitive... Any interference issues with the ignition reluctor built onto the '08 crank wheels? So, just how many XB12s have had big end bearing failures? | ||
| Hughlysses |
Apparently no problems with interference with putting the 08 crank in earlier cases; I'll try and find out all the details when I talk to Darkhorse on the phone. We've had 3 guys (including me) mention in this thread that they had the same bearing failure. I found a thread on a Sportster forum that reported the same failure on a few ~2005 model Sportsters. I don't think it's a very common failure, but it doesn't seem to be unknown by any means either. Maybe this was the main driving reason behind the 08 crank upgrade. I'll be interested to see if Darkhorse has seen a lot of them. | ||
| Skifastbadly |
Just to be perfectly clear I haven't yet done a bearing inspection so I can't be sure my engine puke was a bearing failure. The symptoms are a lot like Hugh's, but I'm not certain. | ||
| Hughlysses |
Haven't had any time to work on the bike since my last post, but I have done some additional research. I figured who better to ask about the 08 crank upgrade than Erik Buell Racing? Here's what they had to say:
I'm gonna try to talk to Darkhorse this afternoon and get additional details from them; I'll post if I find out anything of interest. (Message edited by Hughlysses on March 22, 2011) | ||
| Hughlysses |
I actually got two replies from Erik Buell Racing. Here's the other, which includes the part numbers for the major parts:
I checked on-line, and oddly enough the list price for the 08 crank assembly is $50 less than the cost of the 07 assembly.  | ||
| Tootal |
You might also consider a new primary chain, and bronze gear for the oil pump while taking the engine this far apart. Might also consider the XB9 Primary gear since you have to buy one anyway! That way you get a new chain too. | ||
| Hughlysses |
I spoke to Darkhorse; sounds like a pretty straight forward job. He says they've actually been doing the conversions since 07, apparently as part of development work for the XBRR and 08-up engines. BTW- he mentioned that the XR1200 has the upgraded crank but other Sportsters do not. A couple of specialized tools are required for crankcase disassembly/reassembly, so I'm considering having them do the actual install. I could also get the crankcase bearings replaced and the races align-honed so I'd know the job is right. The bitch about that is probably shipping charges from SC to WI and back. | ||
| Hughlysses |
Might also consider the XB9 Primary gear since you have to buy one anyway! That way you get a new chain too. My thoughts exactly. I've been pretty happy with the stock gearing, but if I'm doing all this stuff I'm interested to try it. | ||
| Itileman |
The XB9 gearing is the best mod I've made to my XT. Never mind the off road benefits. You can actually downshift in the twisties and engine brake. | ||
| Tootal |
A higher revving lower geared Uly is going to make you glad it blew up. Well, as soon as your knuckles and your wallet heal up! | ||
| Natexlh1000 |
Does this mean the charging circuit has to be changed too? | ||
| Hughlysses |
I don't think so- I believe you press the rotor off of the 07 crank sprocket and onto the 08 crank sprocket. | ||
| Tootal |
Hugh, from what I remember, the 08 sprocket comes with the rotor already on it. Pressing the 07 off is a PITA! I thought I was going to shatter my magnets. I did it but was really being careful. I don't think they sell just the sprocket anymore. | ||
| Hughlysses |
Hmm, I should have asked Darkhorse and I forgot. Coincidentally, there's a thread on the XB board by an XB12R rider who found out his 2005 model has a 2008 crankshaft when he went to install his new 2007 XB9 primary sprocket. http://www.badweatherbikers.com/buell/messages/327 77/622714.html?1300899733 I'll post in that thread and see what he can tell us. | ||
| Hughlysses |
Well, the second-most unpleasant task I had to complete is now finished: 2010 income tax returns. Fed & state finished & filed, and much to my surprise, we're actually getting refunds. Now that THAT's off my plate, I can get serious about finishing the Uly teardown. | ||
| Electraglider_1997 |
Hugh, As you are well aware, that only means that Uncle Sam used you for a no interest loan. Probably me also. | ||
| Hughlysses |
Craig- Yea, I know. I'm just making up for last year when I found out I'd inadvertently borrowed several grand from Uncle Sam that suddenly had to be repaid. That will ruin an otherwise good day. I heard from Darkhorse regarding any problems with using the 08-up primary sprocket/rotor with the earlier stator; here's their reply:
Sounds like it won't be a problem. | ||
| Hughlysses |
I've been at it most of the day. The engine is out and partially stripped. Have to decide how far I'll disassemble before I ship to Darkhorse for the crank replacement. I'll post pics later. | ||
| Hughlysses |
http://cgi.ebay.com/ebaymotors/2009-Buell-XB12R-En gine-Motor-Complete-_W0QQcmdZViewItemQQhashZitem45 f9a4d742QQitemZ300541073218QQptZMotorcyclesQ5fPart sQ5fAccessories Hmmm, a 2009 XB12R engine (~5k miles) with oil cooler, complete wiring harness, ECM, and voltage regulator. I wonder what it'd take to adapt that to my 07? |
