Author Topic: Decarbonization, piston upgrade, drill case for old style breather  (Read 11163 times)

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mattjohnson207

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Parked my '09 AVL several months ago due to hard starting, metallic top end noise, and constant kickback. 8,000 miles.  Need a laundry list...Want reliability above all.  I definitely want to drill out the case to go back to the old iron barrel style breather. ( for off road use only of course:)  I read the previous tread on piston/ cylinder specs...don't have that kind of expertise ...but want to upgrade piston  for my peace of mind, and anything else I may have overlooked. Was thinking  32 mm Amal mk1,or  TM32 mentioned in a recent thread. 
   Reliability and peace of mind is my main goal, not necessarily  performance.....
    Thanks,  Matt in Glendale


mattjohnson207

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Forgot...I also want to drill out the head and install an enfield decompression valve ,looks like a pretty simple installation ,  10 mm as opposed to the  larger Harley,  All I have are a hand drill and  tap, am I being too optomisic?  Searched Nfield gear for decomp valve...
« Last Edit: July 23, 2013, 06:39:58 am by mattjohnson207 »


DanB

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Hi Matt,

Sounds like a good project, so please share progress and lots of pics!  Have you seen Adrian's decomp thread:  http://www.enfieldmotorcycles.com/forum/index.php/topic,16052.0.html

If you're out for reliability and are opening the case anyway, you should think about bearings / conrod as well. 
« Last Edit: July 23, 2013, 05:14:59 pm by Kevin Mahoney »
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ERC

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Don't know if you can put the old style breather on an AVL. Ace may know and would help you with it.  ERC
2-57 Apaches, 2-57 Trailblazers, 60 Chief, 65 Interceptor, 2004 Bullet, 612 Bullet chopped.


mattjohnson207

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Was looking at some of the old threads, not sure, but if the case doesn't have  the crescent shaped relief  or cut out for the breather, I'd get my Mikita grinder and 4" disc. And  shape out the 1/2" X  2"  X 5/16 crescent relief .  Hopefully?  Sounds like a great mod


Ice

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 Per factory service manual  for the AVL, piston to cylinder clearance is .08-.10mm (.003-.004in) when new and the service limit is 0.30mm (.012in)

 Those numbers sound pretty big but they diminish quite a bit as the piston expands.
 
 The AVL came standard with a forged steel conn rod, a roller bearing big end and an oil pump that flows a lot more oil than any iron barrel hi volume pump could ever hope for.

 I believe the pistons to be pretty decent as I don't ever remember hearing of one giving trouble.

 If I had an AVL the breather and the de-comp are about the only things I would change about the engine itself.

 The AVL had the full length breather lump ( but un-drilled ) on the left side of the crank case until '06. The '07 had a half length breather lump also un-drilled. 
 A drilled '07 lump would need a short hose nipple installed by either threading or pressing.
 The lump has been drilled with the engine intact and in place by one of our forum brothers and the how-to was covered in a thread here.

 Not sure if '08 and later had the lump. If they didn't, fitting a bolt on breather lump like the interceptors used should be pretty straight forward.

  As mentioned adding a de-comp to the head has been done and I like the idea too. I think it is a better system than the valve lift system.
Plenty of meat there to drill and tap not by coincidence but by design. AVL twin spark was a production model available in the Indian home market.

 As far as ancillary equipment goes I would de-restrict the exhaust to make it run cooler of course. Adding a spin on oil filter for better filtration would keep the oil cleaner and make the engine last longer. A thermostat controlled oil cooler wouldn't help the engine any but it would make me feel bettw for the two to four weeks a year it gets hot enough here to want one.

 Installing a low restriction air filter and exhaust along with a 30mm PWK really, really woke up brother Bill Harris's AVL based scrambler.
 His Bullet was always quicker and faster than mine.
Its also quicker than my son's free flow, re-jetted, higher compression trails kitted Bullet

 With the recent addition of a set of S cams it's even quicker than it was before and now pulls like a 441 Victor or thereabouts.

 
« Last Edit: July 24, 2013, 05:53:01 am by Ice »
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mattjohnson207

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My 09 AVL has a nub the size of a small grape where the breather will be drilled .  They say if you sit in an airplane cockpit long enough you'll think you can fly it.  Drill in place...not have to split the cases...not replace the piston...hmmm
   Thanks for Adrian's thread and photos
      Matt
Ps saw Aces thread oct 2 nod 2009.... Looks like I'm  going to have to use the Mikita and split the cases.  That crescent relief  allowing air flow around the sleeve might not be there. Will be a cheap mod though, just the engine gasket set...thanks
« Last Edit: July 24, 2013, 10:58:04 am by mattjohnson207 »


D the D

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My 2007 Iron barrel has a little nub, but beware: that nub is the base of a threaded cylinder stud, not where the breather went.  The breather would have been below it.

'07 Iron Barrel Military (Deceased 14 September, 2013)
2014 Yamaha Bolt R Spec V-Twin
1975 XLCH


Kevin Mahoney

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On average I think you are getting good advice from Ice. In the real work the AVL has turned out to be a good engine. It cools a lot better than the iron barrel, has a better crank and bearings, and oiling system as mentioned. The pistons are good, we had some initial head gasket failures but that seems to have settled down.

The breather leaves something to be desired also as mentioned.
As for an oil cooler I think you should put a thermometer in your oil tank after a good ride. I think you will be surprised, especially with that engine. It runs cooler than you might think. 
Best Regards,
Kevin Mahoney
www.cyclesidecar.com


Ice

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My 2007 Iron barrel has a little nub, but beware: that nub is the base of a threaded cylinder stud, not where the breather went.  The breather would have been below it.

Thanks Br. D the D, I love a mystery!
 
The 64 dollar question.
 When was the lump deleted ? early middle or late '07 ?
 Fellows, please check your engine numbers and let us know the month it was made and if it's lump or no lump.

First digit denotes the year I.E. 6=2006
Last character should be a letter for the production month A= January, H= August, K= September, N= December


« Last Edit: July 25, 2013, 06:53:24 am by Ice »
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D the D

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Ice,
All I can tell you is that my 2007 Iron doesn't have the lump nor the crescent cut inside.  I remember someone else here had a 2007 that had a partial lump and the cut inside.  Ace posted that he's seen 2007s with them.  My date is Feb?  I'll have to check.  Doesn't seem to be rhyme or reason for a cutoff date.  You have to pull the barrel and check for the crescent unless someone knows for sure that the AVL didn't have them.
Good Luck!  I hope you have them.
Dennis
'07 Iron Barrel Military (Deceased 14 September, 2013)
2014 Yamaha Bolt R Spec V-Twin
1975 XLCH


Ice

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Mines an '06 with the full lump ( un drilled ) Brother Bill Harris's AVL also an '06 came with the lump.
No matter where you go, there, you are.


D the D

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March '07 and no lump, no internal crescent.
'07 Iron Barrel Military (Deceased 14 September, 2013)
2014 Yamaha Bolt R Spec V-Twin
1975 XLCH


mattjohnson207

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Thank you all for your encouragement.  Took the head off this morning , easily. The two rocker arm studs came off with it; normal?
        Stuck on the barrel though, hit a protruding  solid part with  hammer and chisel ...nothing.  Figured I'd better wait for advice.
         Pictures tomarrow , work night shift...too tired.
          Again, thanks for all your help
                       Matt


D the D

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Not 100% sure about an AVL.  Someone will let you know.
On an Iron Barrel you need to remove a nut on a stud holding the barrel to the case above the tappet cover.  Also, loosen the two cross bolts holding the case together closest to the barrel.  They clamp down on the barrel.  It should pop right off after that.
'07 Iron Barrel Military (Deceased 14 September, 2013)
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1975 XLCH


mattjohnson207

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The good news is I haven't broken a fin. One case stud is hidden by starter, got the nut off...might still be exerting clamping forces.   Tried a brass drift, chisel, screwdriver ,  no movement.
    In another forum two contributors questioned the wisdom of opening the cases of a perfectly good motorcycle.  The breather mod will have to wait, but the iron barrel decomp valve is definitely going in!
     2009 AVL , 8,175 miles.  98%. Short  8 mile trips in Phoenix , Az , winter and summer .
       Was experiencing  intermittant metallic sound fom the head, marbles Now suspect i should have used  better gas mid grade or premium ,Regular kickbacks,   with an occasional clang.  won't restart when hot. Very hard starting
         Want to inspect rings and do decarbonization .
           ...Matt in Glendale


ERC

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Are you sure you've taken the nut off at the bottom of cylinder on right side. If that's off the cylinder should come off.   ERC
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mattjohnson207

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I loosened  three nuts just below the cylinder. The starter ,or front side has only one nut accessible , other side is blind.  The rear, both nuts are loose


ERC

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Try taking the studs out then you may be able to swivel the cylinder.  ERC
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ace.cafe

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I would suspect that it is the gasket that is holding it down, by way of some gasket compound that they used, or just the gasket itself getting bonded to the castings from heat and time. I see this on the Iron Barrels too.

If you can't get it off using any other method, you can use a thin paint scraper and a mallet to drive the thin blade of the paint scraper into the gasket gap, thereby destroying the base gasket. Work it all the way around from all sides, and this loosens the grip of the gasket on the castings.
If it still won't let go, you can then use a thicker wedge in the gasket gap to wedge the cylinder up, by using a mallet to drive the wedge into the gap, at various places around the base, to move it up evenly. At some point, it gives up and you can get it off.
Just be sure that there are no bolts or studs remaining un-done, and it will come up with methods like this.
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ERC

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Ace is correct on the putty knife use, but the best one I found is the Snap On chisel edge heavy duty gasket scraper. You can really whack it with a hammer and it won't bend and if carefully placed on the gasket edge will cut into the gasket not harming the surfaces.  ERC
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D the D

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Can't improve on those recommendations 'cause they're what I've done on various parts and bikes.  I usually use a stainless putty knife with a beveled edge.  If the cooked on gasket still won't break loose, try soaking overnight with a real penetrating oil like Kroil or Liquid Wrench.  PB Blaster if it's what you have.  That will usually soften the paper gasket and dissolve some of the hardened adhesive.
'07 Iron Barrel Military (Deceased 14 September, 2013)
2014 Yamaha Bolt R Spec V-Twin
1975 XLCH


High On Octane

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A good quality putty knife and hammer/dead blow will usually do the trick.  If it doesn't, resort to obscene profanity and beer and try again.  THAT will usually do the trick.    :D

Scottie
2001 Harley Davidson Road King


D the D

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If you can't take it off without undo force, call Scottie and his drunken cussing should scare it loose!  ;D

Hey, I've been guilty of resorting to that myself.  Beer and cussing, not calling Scottie.
'07 Iron Barrel Military (Deceased 14 September, 2013)
2014 Yamaha Bolt R Spec V-Twin
1975 XLCH


mattjohnson207

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Paint scraper did the trick.  Crescent is about 1/16" deep. If that's not enough, is it a big deal to remove the piston?  Then I'll get out the grinder, make it a little deeper , if necessary?( sealing off the bottom end with some kind of silicone and whatever) and drill for the  brass breather elbow
        We'll worry about getting the correct amount of vacume  later. How hard can it be...
         However, this is my first rodeo, took an engine building class at the community
 College ten years ago;  any advice I can get I will be happy to get.....Matt


mattjohnson207

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The lines in the barrel are of course the front of the bike, only one line is visable to the naked eye, thought it was a scratch from pulling out the barrel, can't feel any roughness.
       The piston rocks from side to side about an eighth inch.       Matt


High On Octane

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An 1/8" of play on the wrist pin seems a bit excessive and worn IMO.  Maybe pull the clip and wirst pin and inspect for excessive wear on the pin itself and on the piston.  Look to see if there are any areas where metal has been worn off.  If there is you need to replace the piston, rings and wrist pin.  Also make sure you inspect the cylinders walls very well, and take a peak at the top of the piston rod while you're at it.

You already have it this far, make sure you give everything a very thorough inspection.  How many miles BTW?

Scottie
2001 Harley Davidson Road King


mattjohnson207

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Got as a leftover, mostly 8 mile trips to work in Phoenix. At 45 mph; summer is hot, winter probably doesn't warm up. 8,175 miles.
       You're. Right...got it this far, might as well do it right
      Matt


mattjohnson207

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And there was that intermittent sound of marbles, hard starting, clanging kickbacks, which is why I'm here...
        Matt


High On Octane

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That marbles sound could very well have been that loose wrist pin.  It shouldn't have any play at all.

Scottie
2001 Harley Davidson Road King


ERC

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When the piston is on the rod the side play is 1/8" on the standard rod and piston. There shouldn't be any up and down play. Also I would measure the thickness of the crankcase wall where you plan to put the breather in. On the 700cc twins the cut out for the breather is 1/4" where the cylinder slides in.   ERC
« Last Edit: July 28, 2013, 11:41:46 pm by ERC »
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mattjohnson207

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Sent out cylinder for honing, can't see any wear on wrist pin, don't have any expertise in this area.  I would guess it would be prudent to re-ring...what would be the best rings to get?  Machinist says piston looks ok.
       The brass barb is almost 7mm
        I could not find any evidence  of the 3mm hole the IB bullets have drilled out to complete the breathing circuit.
         Therefore the breathing circuit must be incomplete in my uneducated opinion.
          Proposal:  why not drill a 3 mm hole next to the 7mm on the other side of the stud; and run a rubber breathing hose to the timing case nipple ( this is a 2009 AVL). , or as I've seen another Brit bike, to the valve cover... To complete the circuit.
           It would be ugly, but efficient,  but at a later date when I open the cases for a bottom end rebuild, it would be simple to drill a proper 3 mm hole in its proper place,  like the  iron barrels are, then just plug the ugly hole with a brass screw, grind off...leaving a beauty mole for the discerning critic.
     Matt
     No children were within earshot of the mechanic during this procedure


mattjohnson207

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A very sketchy  and risky operation.  Drill bound up and twisted on me twice,  though final pass was good.
     Tapping the threads went badly, finally used a 6 inch extension with ratchet , did it in one pass.
       Thickness of the case is about 1/4"
        Used paper towels lined with grease to keep grinding debris out of the engine
         Used a Mikita  grinder; disc about the size of the bore,there was some cosmetic damage to the bore which will be invisable, and of no consequence.
           I'm a pretty good carpenter and used to these tools, and still, disaster almost ensued.
            If anyone is tempted to try this mod, please, use a lot more preparation and planning  before drilling and tapping, and sealing off the innards of the engine then  I did.
           For example, perhaps a cardboard cut out to seal off the inside  bore of the engine, sealed  with  silicone, then you could just vacume the sand from the grinder.
           Fabricate a holding device for your drill.
           Better yet, wait 'til it's time for a bottom end rebuild and do it right.
           But I am so happy with the results... Can't wait to ride a cooler , smoother running AVL!
« Last Edit: August 17, 2013, 09:03:59 pm by mattjohnson207 »


ace.cafe

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It looks good.
I don't think that you would be able to see the 3mm hole in the wall between the crankcase and the oil tank. It's obscured by the flywheels. It should be there, but you just can't see it.
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D the D

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Very nice machining.  Congrats on doing it by hand.
'07 Iron Barrel Military (Deceased 14 September, 2013)
2014 Yamaha Bolt R Spec V-Twin
1975 XLCH


Ice

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Beers to you for doing what till now has only been talked about.
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ERC

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Frankly I can't see how that will work with the cylinder in place the liner will block any cylinder pressure getting to the fitting you've put in there. I think you'll have to mill a passage to the crankcase area below to get it to work. Don't have a bullet apart to check this but all the twins I have are cut like what I described above. Maybe Ace can fill me in on this.   ERC
« Last Edit: August 18, 2013, 02:27:49 pm by ERC »
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ace.cafe

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Frankly I can't see how that will work with the cylinder in place the liner will block any cylinder pressure getting to the fitting you've put in there. I think you'll have to mill a passage to the crankcase area below to get it to work. Don't have a bullet apart to check this but all the twins I have are cut like what I described above. Maybe Ace can fill me in on this.   ERC

In the Iron Barrel engine, there is a gap between the lower portion of the barrel liner that goes into the top of the crankcase, below the breather crescent location.  Maybe somewhere around 1/8" or something like that. This allows air to get out the breather, and uses the lower portion of the barrel liner as a baffle to prevent too much liquid oil from blowing out. I sort of expect that the AVL has a similar arrangement, since the crankcases are basically the same as the Iron Barrel.
« Last Edit: August 18, 2013, 04:21:58 pm by ace.cafe »
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ERC

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Thanks Ace, When I look at the pictures it looks like the case would be very close to the sides of the cylinder. Will be interesting to see how this turns out having never worked on an AVL.  ERC
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mattjohnson207

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Thanks everybody for the encouragement.  I have an iron barrel short block I picked up on e-bay, probably just for the purposes of this discussion,  have to go to work, will look at it later.
       Matt


mattjohnson207

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Here's some pics of the iron barrel, if it helps.the depth is the same, 3  3/16 for both
       There is a 3  22/32"vs 3 21/32" for the opening diameter.. The iron barrel has a slightly wider opening,  looks to be 1/16.  Can't tell about the inside where  the air flow is for the breather,  have to get a set of  gauges... Sure they're probably identical, don't see any reason they would change it
     Matt
« Last Edit: August 18, 2013, 07:49:00 pm by mattjohnson207 »


DanB

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Reply #41 on: November 06, 2013, 03:07:48 am
I'm bumping this. Matt, how did this turn out?  You happy with the results?
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
2006 AVL Electra


mattjohnson207

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Reply #42 on: November 07, 2013, 05:26:52 pm
Hi Dan, while I had the bike apart I had super finishers in Phoenix, Deer Valley, put in a decompression valve...did a nice job,will post a pic later. 
        Waiting on new rings, gaskets etc,  some stuff on back order, hopefully I'll know how it all works out in a couple of months...finances.
           I'm sure it will be fine
             Thanks for asking....Matt


DanB

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Reply #43 on: November 07, 2013, 07:04:24 pm
Cool!  Cant wait to see the pics.  Thanks Matt for updating.

Dan
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
2006 AVL Electra


mattjohnson207

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Reply #44 on: November 07, 2013, 07:46:48 pm
Dan, if you try this breather mod, the aluminum case is very soft and the drill can easily get away from you
        Matt


mattjohnson207

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Reply #45 on: November 12, 2013, 05:50:41 pm
Promised pics, Dan,   Expect  to have  bike together in a month or two  ( old style decompression valve installed on a 2009 AVL). Inside head is a tiny hole for compression release
    Matt
« Last Edit: November 12, 2013, 05:54:20 pm by mattjohnson207 »


DanB

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Reply #46 on: November 12, 2013, 10:17:27 pm
Thanks Matt.  Looks like nice work there; must have been a bear getting through those fins.  Also, thanks for the heads up on drilling the old style breather.  I've got an 06 that still has the lump on the side of the case.  Not sure if i trust my drilling technique however...
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
2006 AVL Electra


mattjohnson207

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Reply #47 on: November 14, 2013, 02:15:17 am
Hi Dan, I had a superfinishers  across from the deer valley airport do the decomp valve, glad I did.
   Your bike...if the drill gets twisted and you have to drill oversize...there's always helicoil!
      Hope it works out for you the first  time
         Best,   Matt