Author |
Message |
Bdb_csiii
| Posted on Saturday, December 17, 2011 - 04:48 pm: |
|
Need some guidance; Got a '04 XB12R with 48K. Mostly street miles, but have done 4 track days with it. At the last track day it started making a bunch of noise in the lower right crankcase. Pulled the motor and tore it down. Pretty sure I've got a bad connecting rod bearing, but the main part that concerns me is the cam bearings in the crankcase side were seized and 3 of them appear to have spun. I've attached a couple of pics of the crankcase. You can see the discoloration around the bearing bores. I'm on a limited budget but would like to get the bike running again. What are my options? You honest input would be appreciated.
|
Satori
| Posted on Saturday, December 17, 2011 - 05:58 pm: |
|
There was a thread about a similar problem on the uly board a bit back. If its a bad crank bearing, to do it right by the time your done you are looking at about 3k. I did see yesterday on the seattle craigslist a 2009 a xb12ss motor for sale that was pulled from a totaled bike, with all the FI for 1600, its not me or anyone I know, but it would be a cheap option, plus you get a better crank, better oiling. its just a thought. check out the uly board to. Good luck |
Greg_e
| Posted on Saturday, December 17, 2011 - 06:49 pm: |
|
They say those bushings can not be replaced, but a few people have purchased sportster bearings and cut the slot in them for oiling and pressed/glued them back in. After that you are in for new cases or have them machined for needle bearings. Needle bearings would be best but going to cost some money. |
Cpatt
| Posted on Saturday, December 17, 2011 - 09:11 pm: |
|
i spun and seized one of my cam bearings. and HD said i needed a new crank case... so i got a new engine. its just cheaper and now i have a parts engine. but i am around 3500$ in parts in to it now |
Panhead_dan
| Posted on Sunday, December 18, 2011 - 12:00 pm: |
|
A friend spun a cam bearing in his big twin recently. The cheap fix was to machine it out and press in a steel bushing to get back to the outer bearing size. $150 to the machinist and about $50 for bearings. |
Ericz
| Posted on Sunday, December 18, 2011 - 06:17 pm: |
|
There are a couple of XB engine cases on eBay for around $250-300 right now. That is another option. |
Greg_e
| Posted on Sunday, December 18, 2011 - 09:50 pm: |
|
Could a decent machine shop remove the bushings, weld the holes full, then machine and put new bushings in? |
Ericz
| Posted on Monday, December 19, 2011 - 09:10 am: |
|
The only problem I see in machining new bores for bushings is that the existing bore centers may be hard to find within the necessary tolerances. You would be relying a lot on the machinist to give you 4 properly aligned cam bushings! |
Natexlh1000
| Posted on Monday, December 19, 2011 - 10:15 am: |
|
Are oversized bearings available? I know oversized bronze bushings are available for the cam cover side at least. It might be worthwhile to ask experienced sporster mechanics. |
Slaughter
| Posted on Monday, December 19, 2011 - 04:02 pm: |
|
I have paid good money now twice to John Dahmer at Dark Horse Crankworks and if anybody can do the work, he certainly can. Send him an email. Normally he is really quick to respond. www.darkhorsecrankworks.com/ |
Greg_e
| Posted on Monday, December 19, 2011 - 11:31 pm: |
|
I wonder if they might have made a jig for this type of work so they can locate the bore properly. I wonder if Mr. Buell could leak the measurements so a set of alignment points could be found so a good shop could set it up on a mill and fix these. |
Slaughter
| Posted on Tuesday, December 20, 2011 - 09:53 am: |
|
See Darkhorse, this is what THEY DO for a living! If you had a vertical mill in your garage, you could fix this yourself... but... |
Slaughter
| Posted on Tuesday, December 20, 2011 - 09:59 am: |
|
The other thing you must ask is if the problem is the big end bearing or if the flywheel itself is going bad. You don't want to put money into the cases only to have them beat to pieces in a few miles. Darkhorse (or any moto machine shop) can measure run-out on the flywheels. This type of bottom end damage is kind of typical of these motors when they've been hitting rev limit often. Cam journals still need to be looked at. |
Bdb_csiii
| Posted on Tuesday, December 20, 2011 - 09:29 pm: |
|
Thanks everyone, I appreciate your input. Having been a machinist at one time I kinda figured what you've been saying. I wish I did have a mill, it would be nice to have. I will contact Darkhorse to see what they got to say. |
Slaughter
| Posted on Wednesday, December 21, 2011 - 11:49 am: |
|
Duuuh... I lost count - this is the THIRD time I've done the big bottom end mod with Darkhorse. I pay retail so I don't owe John any favors - I'm just very very pleased to have spent the money for the third time (build is underway and HOPE to be racing it in January) |
Bdb_csiii
| Posted on Thursday, December 22, 2011 - 08:17 am: |
|
Thanks Slaughter, I will be contacting them to see what they recommend. |
Motohead1125r
| Posted on Friday, December 23, 2011 - 06:48 pm: |
|
I have the same issue with an 07. On mine I had bad leak down on the front cylinder and the extra heat caused the front two inner bushings to spin in the case. the spout of the jugs are right next to the inner bushings. I found .005 oversize bushings from Jims, and plan on getting one of his pinning tools while I'm at it. My rod bearing is fine, but i will be sending the crank to darkhorse for a rebuild and pin upgrade. I knew this motor had issues, the front leakdown was getting way worse than the rear, and the motor was starting to make noise, but had i dealt with it sooner, i dont think this bushing issue would have happened. |
Steve_mackay
| Posted on Sunday, January 01, 2012 - 12:59 am: |
|
I am a machinist, have access to some of the best tooling and equipment money can buy. I'd STILL trust Dark Horse who does this type of stuff for a living. |
Clutchless
| Posted on Thursday, January 05, 2012 - 08:04 pm: |
|
and what has darkhorse to say about your cases? I dunno about anyone else but I'm waiting to know, just in "case".... |
Bobbuell1961
| Posted on Sunday, January 08, 2012 - 11:29 am: |
|
If you use the Jim's oversized bushings make sure you check the end play in the cam as the face on them is thicker. I'm sure anyone fitting bushings would check but i thought i'd mention it. |
Skinstains
| Posted on Friday, January 20, 2012 - 01:26 pm: |
|
I might have a set of cases for you if that's the route you want to take. |