TIG Yamaha dirt bike crancase.

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My son bought a used and abused dirt bike, 1st one, a 2000 YZ426F, Yeah I know, little overkill.  anyway the housing where the clutch cable activates the clutch rod has a chunk out of it where someone JB welded it and you know how long that lasts. This is on the actual cranckcase, it looks Aluminum, The outer side covers that unbolt say right on them, Magnesium, but have a different look and color to them. Anybody know it the cranckcases are aluminum or Mag. I have welded Aluminum with the TIG but not Magnesium.  Any major difference if need be. I was planning to put a piece in and weld around to seal it as I don't want to just build it up, that would require teardown and machining. I will post a picture when I can. Ben if you read this , post a picture."Si Vis Pacem Para Bellum"Lincoln Idealarc 250 AC/DCMillermatic 251   Syncrowave 300   30A spoolgunLincoln MP210Hypertherm 45(2) LN 25(2) Lincoln Weldanpower 225 CV(4) SA200   1 short hood    SA250    SAM 400
Reply:Pretty sure it's Magnesium, not sure about any differences on how to weld them (not even close to the person to ask for that). I would consider using an aluminum brazing rod & a torch along with your piece your planning to put in to fix it. I have a couple of old yamaha's with the magnesium cases and one is cracked. I planned on trying the aluminum brazing rods for my problem.
Reply:I find the best way to know if a set of cases is weldable is to weld on it. If it starts boiling and gassing out, chances are you won't be able to weld it.
Reply:[ame="http://www.youtube.com/watch?v=weqTWwaaL0g"]http://www.youtube.com/watch?v=weqTWwaaL0g[/ame]Last edited by MikeGyver; 07-12-2011 at 07:39 PM.
Reply:I TIG welded one of these a couple years ago, think it was a 450F not sure, it was broke in the area you describe, tough getting clean but welded nice once I got it cleaned, still holding up. The guys kid races it around here every Sunday
Reply:I do a lot of those, thrown chain brakes the area you described. The covers are mag but cases are al, I use 4043.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:I'm willing to bet the cases themselves are aluminum.  It's not unusual for dirtbike mfgs to use mag for the clutch and/or stator cover
Reply:Castweld , sounds like you are in the know, yes looks like thrown chain, What parameters would you suggest, Amps, Tungsten, diameter of 4043.  I can turn the bike flat to make it simple. Would you put a piece in and seal around, or do I have to gut it, fill and re machine. Trying to avoid machining. Could possibly have a copper rod turned to same diameter and swap for clutch activator and weld and fill. Here's some pictures. I know , new chain and lot's of cleaning before welding. It was patched with what must have been JB weld. did not see this when he bought it.     Love my mid rise car lift, also making it do double duty.  Thanks. Attached Images"Si Vis Pacem Para Bellum"Lincoln Idealarc 250 AC/DCMillermatic 251   Syncrowave 300   30A spoolgunLincoln MP210Hypertherm 45(2) LN 25(2) Lincoln Weldanpower 225 CV(4) SA200   1 short hood    SA250    SAM 400
Reply:I would suspect there's a seal in a counterbore at the face of that casting boss under theexposed arm.Blackbird
Reply:Pull shaft to check for bend. Dave is right there is a seal at the top and there is a needle bearing just under that. The bottom of shaft is in al bore. Pull seal and replace I think its only a few bucks. The needle bearing will get over heated easily, weld a small section at a time or replace it when finished.Looks like your bottom, bearing, and seal bores may be good and all you need is to cover center missing section?I'd use 3/32 tung, I have pedal so..... I set machine to 250 and use whats needed. 4043 filler.Get ALL of the JB weld out before starting, thats got to be the nastiest stuff when it gets pulled into the puddle.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Originally Posted by castweldGet ALL of the JB weld out before starting, thats got to be the nastiest stuff when it gets pulled into the puddle.Peter
Reply:Originally Posted by WeldingMachineYou aren't shatting!  I just dealt with that on a radiator today.  what a mess..
Reply:Where are you in CT. kolot?Maybe you can run it up to me and I will take care of it for ya.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Zap, I'm in Stafford Springs, about 10 miles below Sturbridge, Not far from I84 and a quick ride to the Mass Pike. Zap, that is a very nice offer, I have always wanted to get to one of your clinics but haven't made it yet. Probably and hour from you give or take if i'm not mistaken. Always up for a ride.Would that be done with the shaft in place or taken out, If out how do you keep it from intruding on the bore so it doesn't have to be machined? I was thinking of having a copper rod turned the same OD, or is that overkill. Probably would be tough getting it out though. Let me know if you want to do it and Thanks.  Also my TIG is limited to 30 Amp plug right now, My cousin is and electrician and found my feed is inadequate and cut me back to a 30 amp breaker. I have to dig and lay in a small run of PVC conduit and he will get me up to 150 amp service. Just haven't done it yet. Don't think I would get far with 30 amps, but would definately keep me from overheating it or welding to much at once. LOL>  Zap, if I did come, can I bring my helmet, HINT, HINT!    Peter, if you read this , same question on the bore, shaft in or Out? Curious if you can just work the edge and walk or bridge over the steel shaft?Last edited by kolot; 07-17-2011 at 10:57 PM."Si Vis Pacem Para Bellum"Lincoln Idealarc 250 AC/DCMillermatic 251   Syncrowave 300   30A spoolgunLincoln MP210Hypertherm 45(2) LN 25(2) Lincoln Weldanpower 225 CV(4) SA200   1 short hood    SA250    SAM 400
Reply:Zap, I'm in Stafford Springs, about 10 miles below Sturbridge, Not far from I84 and a quick ride to the Mass Pike. Zap, that is a very nice offer, I have always wanted to get to one of your clinics but haven't made it yet. Probably and hour from you give or take if i'm not mistaken. Always up for a ride.Would that be done with the shaft in place or taken out, If out how do you keep it from intruding on the bore so it doesn't have to be machined? I was thinking of having a copper rod turned the same OD, or is that overkill. Probably would be tough getting it out though. Let me know if you want to do it and Thanks.  Also my TIG is limited to 30 Amp plug right now, My cousin is and electrician and found my feed is inadequate and cut me back to a 30 amp breaker. I have to dig and lay in a small run of PVC conduit and he will get me up to 150 amp service. Just haven't done it yet. Don't think I would get far with 30 amps, but would definately keep me from overheating it or welding to much at once. LOL>"Si Vis Pacem Para Bellum"Lincoln Idealarc 250 AC/DCMillermatic 251   Syncrowave 300   30A spoolgunLincoln MP210Hypertherm 45(2) LN 25(2) Lincoln Weldanpower 225 CV(4) SA200   1 short hood    SA250    SAM 400