Vintage Dirt Bike Q & A

Has anyone attempted to weld their own engine cases? If you have, please post your tips here. Also, if you done it with a Mig Welder, please post your tips because I have a broken case and need some tips. Thanks

A mig might be alright. Go to your local welding supply company and ask for there recommendations on welding magnesium with a mig. Might be better to use a tig setup as it gives you more control with the heat. To much heat can warp or weaken the magnesium. You can also use an oxygen/acetaline torch to braze it but that takes some skill!

_________________
W.F.O. All the way!

The engine cases are aluminum...the covers are magnesium...and are marked that way for a reason.eL

_________________
1974 Honda CR250M
1979 Honda CBX SS

I just paid for a pair of MT 250 engines. Should be getting them in the next 2 weeks. If the cases will swap with yours, I could make a hell of a deal. One is apart and one is together. I want to combine some parts for my MR but, will have spare pieces.

Song remains the same.

I upgraded my Weldpak wire welder to gas with the intent of fixing some cases. Total cost on top of the initial cost for the welder was probably $250 for the inert gas tank and Lincoln conversion kit.

But I found a set of cases on eBay for ~$15 so I bought them instead.

Too lazy in winter to install the Al welding set up for no good reason. Problem is I do an awful lot of steel wire welding and it uses a different gas mix => buying another tank. So I just stick<sic> with the internal shielding gas wire. I've been told the switch to solid wire and shielding gas will make my welds look prettier but won't make the them more functional. Figure none of my bikes get raced so good'nuff to hold together is good'nuff.

My current thought would have been "I need a wire welder for Al, one for steel, and one for internal shielding gas" but the advice I got from the welding shop gave me pause. He said best solution would be TIG but second best would be one of those guns that has the spool of wire mounted on top of it. Al wire feeding through a long cable is supposed to be unreliable. Standard MIG/Al welding was 3rd choice.

Good to know that the cases are aluminum. still better to use TIG. ricortes using inert gas and solid wire will produces a stronger weld. the internal shelded wire produces air pockets and forien material into the welds, it will be weaker and is easier to brake. it is intended for hobbiest who fix rod iron fences or what ever. You want strong welds on your bike. And its not just about being pritty.

_________________
W.F.O. All the way!