cases -- aluminum or magnesium???

I've got a crack from my shift lever getting pushed into my left case-

Is it aluminum or magnesium???
It's an '83.....


Rich

Magnesium. Can be welded but if just cracked, clean it really good inside and out and a little JB Weld and it will be good.

I'll confirm that the left and right crankcases are definitely magnesium. The left outer clutch cover that holds the shifter and kick starter appears to be aluminum on my '88. I tested all the cases with vinegar and this outer cover didn't bubble, indicating that it was most likely aluminum. Maybe they changed to aluminum for this case on the later models because of water pump corrosion issues?

Mag,, and yes,, a skilled welder can weld it...wont be cheap..but can be done..
last time i had Mag welded, a 4 inch crack cost me 150.00
JB Weld willl work for a while, but heat will effect it after a while...
Husky didnt start using Aluminum again until 1987..and only on the clutch side cover, do to issues with the water pumps eating away from water and anti freeze. the inner cases are stil Mag, even up till 2001.

Husky started using aluminum on the clutch case in 1985-86 as the water cooled side cases where failing, these where swapped over on factory recall.
The way you can also tell is the early magnesium cases have the kick start bumper glued on, and the ally cases have the kick start bumper held on with a small screw. Also inside is different casting #s (cases from a 250-400-500 LCs, from 1984-1987 are all interchangable, perhaps more years aswell)
l never knew about the vinigar test, i have done it on my 'screw'-ally cases and swing arm, no bubbles, i dont have a mag case handy to double check.
Great tip!!

hmmm.....I talked to a couple folks about welding and I agree that it is definitely a specialized process due to cost of materials for welding and experience needed for quality. I'm west of Seattle and I've already had to call around Tacoma- still can't find anyone.
I think that I'll start talking to Twinshocker about some of his CNC cast covers for long term. I've owned the bike since new and plan to keep it - so I'm okay with the $$ investment.
Short term I'm going to JBweld for the next race weekend in Goldendale.

Thanks guys for the discussion and info- I always feel better about a decision when I feel better informed.

Rich

Here's a silly question - JBweld applied inside or outside??

I'm thinking outside because I really don't want the chance of the JBweld getting into the internals.....maybe just over cautious??

I kind of have to chuckle, yes the magnesium rod generally they try and get you for something silly like a hundred dollars a pound however some folks are pulling the wool over your eves so to speak about the rest. Cast magnesium has a lot of impurities and won't weld like clean aluminum but it isn't any harder. I punched a hole in mine and have a v shaped weld in one cover. All I have is a dinosaur ac dc tig yes an industrial one but it has no ac balance, no pulse not square wave. Baking the part in the oven for an hour might help get some of the oil out. It wouldn't hurt to weld it hot out of the oven as sometimes you have some strange cracking noises on temperature changes though I don't think things are restrained enough for problems like that with this repair.



If you look at this picture you can see some of the repair, note also I have added (weld blob on and machine with end mill) the extra bolt hole to the cover about two inches above the kick start pivot. The engine core I also added the bolt to has since worn out and the cases this is on don't have that extra bolt. It also has some welding around the kick start shaft and has a bronze sleeve in there. It has seen a lot of use.

I would put the epoxy on the outside that way if it falls off it won't get stuck anywhere and you just might flip the bike up in the air again.

we just did a major case repair on a 2003 450 with the dreaded kick start shaft break,
used 3M panel bond...awesome stuff, turning temp is around 300 deg,
takes 24hours to set, and a special appl, gun...most auto body shops wil have it..
it does have to be clean,,,and is stronger then welding sheet metal.