XB12Scg about to getweir'd project thread

[getweir'd]

Hey all,

Intro: My name is Aaron. I work at Vibrant Performance and love all things grass roots DIY, especially fabrication. This is going to be a thread for my 2008 XB12scg and all the projects/upgrades, experiments I build for it. (Previously owned a 2004 XB9S) I enjoy sharing my experience with the community of which I am an enthusiast of. I also openly welcome and am grateful for other member's experience, expertise and opinion.

Bought in 2020 from the original owner:




First summer upgrades: K&N filter, lighting upgrades from LightningLED and some bar end mirrors. Was focused on enjoying riding with my girlfriend:

 

[getweir'd]

No idea why the photos load upside down? Anyway:
View attachment 16186
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Discovered that it was leaking oil, so apart it came:
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gasket is completely flat
View attachment 16190

 

[getweir'd]

Modified covers:

 

[getweir'd]

Header started:
View attachment 16195
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[Cooter]

THAT explains it! I was wondering how TIG welding bungs and AN fittings was easy for you, lol. I got a lot of stuff from Vibrant in the last couple years for the Buggy:eagerness:

Try re-uploading the links.
I've found adding pics through the uploader on this site too fast breaks the links for some reason. Better to paste the {IMG} link from a hosting site like Flikr.

 

[34nineteen]

Its too late now, but a better way would have been to pick up some later model Sportster valve covers and modify them. They are just blank over that spot as they still breathe through the carb/TB mounting bolts. The XB ones are a bit harder to come across and some people like to replace the stock setup on their earlier bikes (or Sportster) with these valve covers to use the XB "turret" PCV valves.

Oh well....


https://www.harley-davidson.com/us/...zzR-N0qy1JSRwk75KLhoCXJIQAvD_BwE&gclsrc=aw.ds

 

[34nineteen]

And all along I thought you were just into small dams and affecting river levels and flow rates. Who knew?



weir

noun
a low dam built across a river to raise the level of water upstream or regulate its flow

 

[getweir'd]

New header is coming along.

 

[getweir'd]

And all along I thought you were just into small dams and affecting river levels and flow rates. Who knew?



weir

noun
a low dam built across a river to raise the level of water upstream or regulate its flow
badass

those who know, know. previous/ongoing project:
http://www.speedhunters.com/2016/10/crx-rwd-turbo-a-honda-surprise/

 

[getweir'd]

Fuel line converted to -4AN:

 

[getweir'd]

Update. Exhaust turned out great. Vent lines also good. Made an intake and catch can that fit under the airbox cover.

 

[getweir'd]

 

[getweir'd]

Then, poor HD engineering kicked in. Took a bit of work to diagnose the problem. Bike died while mid-ride. Was lucky enough to have a couple friendly neighbors give me a lift home (i wasn't involved in loading/tie down and the bike fell over in the back of the truck). Did a compression test and 10psi rear cylinder, 0psi front cylinder. Pulled the oil pump and the timing looked off but noticed the real problem - the pinion gear retaining nut that is only secured by loctite from the factory (probably assembled on a Friday afternoon shift) backed off 3/16" and the pinion gear disengaged from the pinion shaft keyway and the valvetrain stopped moving while the pistons kept going. Front cylinder valves and pushrods bent. Time to refresh both heads. Will be ordering Kibblewhite kit but am having trouble sourcing pushrods. I thought they have them but can't find on their site.

Pinion gear and nut removed:

You can see the keyway poking out from the spacer on the pinion shaft:

Poor engineering- never in my life have I seen a keyway not go through a gear completely:

Luckily, only minor damage to the oil pump housing. Why is there not a snap ring behind the nut to prevent it from backing off? Thank you HD engineers...

Witness marks on the bent valves from contacting the piston:

No deformation on the piston or the valve seats (heads have been vapor honed). May get lucky and not need to recut the valve seats. Need to lap new valves in first:

I'm not about to split the entire engine to replace the pinion shaft so when everything goes back together, the pinion nut will be stitch welded to the shaft and the oil pump will come off at the end of every riding season for inspection of the welds.

 

[getweir'd]

Don't have a spring compressor, so made one from a piece of 1" square tube and a clamp:

 

[34nineteen]

I'll look through my stuff and see if I have an extra set of pushrods. Pretty sure I do. SHUT UP COOTER!

There should be a locking plate to hold the nut in place.

edit: I cant find it in an illustration , but I know for certain my S1 had this locking plate. Now, I cant remember if my XBs did or not. I'm sure it did... possibly... but for some reason I can't find an illustration of it. I'm probably wrong.


This is what it looks like.
https://www.ebay.com/itm/222112280076

edit again: you have the 2008-2010 engine. I dont know what I'm talking about.

 

[getweir'd]

I really appreciate you checking your spares for pushrods! Yes, 2008 XB12. I don't need anything adjustable, just stock settings. Will post more updates as the rebuild progresses (mostly to make sure I'm not making a mess of it).

Thanks!

 

[34nineteen]

I really appreciate you checking your spares for pushrods! Yes, 2008 XB12. I don't need anything adjustable, just stock settings. Will post more updates as the rebuild progresses (mostly to make sure I'm not making a mess of it).

Thanks!

I'll look when I get home. They are just regular solid stock pushrods, as the Buell covers dont really allow access for adjustment. They should be the same for all XB models.

I'm sure you know this, but the intake and exhaust pushrods are different sizes. They are very close, so you wont see a difference unless you are looking closely.

 

[getweir'd]

Yes, marked them when they were pulled out. Have been using the service manual as a guide. The bent ones are only bent by 0.01" (measured with a dial indicator) but you can easily see they are wonky when you roll them on a flat work bench. The rear cylinder push rods are ok so will put them back in. Just need a single set.

 

[34nineteen]

Yes, marked them when they were pulled out. Have been using the service manual as a guide. The bent ones are only bent by 0.01" (measured with a dial indicator) but you can easily see they are wonky when you roll them on a flat work bench. The rear cylinder push rods are ok so will put them back in. Just need a single set.

No worries. I'll let you know this evening.


BTW, looking at this pic, you should make a front mount for the header pipe elbow. There should be some bushings that press in where the hole in the front of the case is. Not saying its a priority now, but lets stop that from cracking that great looking exhaust later down the road.

Lastly, when putting the bike back together, put the intake back on the bike before you install the rocker boxes/pushrods to verify the intake manifold seals are actually sealing. I would hate to see you have to pull it all back apart to re-do them, and/or doing them with the motor in place is a huge PITA (shut up CoOter, I know what you're going to say). I swear by the stock OE Harley (from the dealer) seals myself.

 

[getweir'd]

Thank you for the heads up on the intake seals. Will review the service manual and heed your advice when assembling. The exhaust photo is before it was fully complete. A front bracket was added to the elbow that ties into the bushing- had to make one out of aluminum- not ideal. The rear has also been re-done with rod as it didn't take long for those tabs to break off.