Rear swinging arm weld?

[2wheeltrundel]

Can anyone help with advice on if a weld repair on a rear swinging arm would be acceptable for passing an MOT test. The bike is a 2005 Chinese built Suzuki EN125 and the bridge across the two arms at the front near were it pivots is totally shot, I have full confidence in my ability to reweld and make this good and strong but because its structural and not just a cosmetic repair will it get through the test, don't want to waste a pile of time on it for nothing 

[Old-codger]

If you are capable and the metal that you need to repair is strong enough you will have no problem with the MOT. make sure the inside of the swing arm is ok as usually what you can see on the outside is usually far worse on the inside. Dont forget heat transfer could bugger up the bushes/bearings. Have you looked at getting one from a breakers in better condition.

[2wheeltrundel]

Had a look on ebay, there used to be loads of used frame bits for these I think they maybe all been scraped now, there are two frames on ebay at the moment both have no rear swinging arm and some new arms for the GS and GN models. I have removed all bushes and made a simple jig support to keep it all true to prevent heat warping. 

[Mississippi Bullfrog]

My welding isn't the best but I've never had a problem with getting repairs past the MOT guy. Not pretty but certainly strong enough.

[2wheeltrundel]

An update on my Suzuki EN125 swinging arm. I attempted the weld but what seemed solid outside was paper thin inside, I was blowing holes in it on minimal power needed right from the start, so a NOS one was found and I've gone from a quick chuck a bit of paint at it to "lets do a proper job" so the only thing left in the frame is the engine and front end and I decided to spend a bit of time and money making it look like someone might actually love their little Chinese built Suzuki 125. Which I actually do.   

( the rest of the frame is really sound surprisingly) 

[Old-codger]

Thats usually the way if it looks bad on the outside you can be sure the inside will be worse unfortunatly, you did the right thing replacing it. They are made so cheap its lucky there is paint on the outside of the arm but you can be sure they wont have put any rust prevention inside. 

[2wheeltrundel]

Your correct, I can see inside of the box cross section and there's no paint in there and a better purpose built rust trap would be hard to find, so it's going to get the full treatment, soaked in a bath of oxalic acid, paint tipped inside and sloshed around when thats dry going to melt some underseal and pour that in too, then see if I can make something to minimise water ingress but allow air to circulate.