the swede Posted December 30, 2012 Author Report Share Posted December 30, 2012 Great advise and info guys. Keep it coming. I am in the Worcestershire paul W. The cases have cracked and been welded and crudely machined / ground back around the swing arm pivot mounts. Also on the clutch side, the eccentric gear change adjuster bolt hole has been mullered and liquid metaled back in. The reason for the dismantling was the gear lever return spring disintegrated and was making a horrible noise. I was advised to check the gear box. So for I've just got the lump out and cleaned out the bits of broken spring, then we noticed the cracks and the heat discoloration in the inside from the welding and the cracks on the outside. My bro said its a new cases job but my thoughts at the mo are, get the new spring and gaskets, put it back together and ride it for a bit, then cut my losses and trade it in at my local shop taking a £1000 quoted hit for the work to be done before the bike could be resold Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted December 31, 2012 Report Share Posted December 31, 2012 I know many will say this is not a right fix; however, I know some people who have used a metal filled epoxy (JB weld in USA) to repair cracked cases. Many of those repairs have lasted for years and years. This type epoxy is hard enoough that you can machine it, drill and even tap holes in it. As with any adhesive, the key is a super clean surface, possibly made a little rough for the epoxy to bite better and plently of time to dry and cure fully. Keep in mind that if the original case was 5 mm thick, you will need at least 5 mm of epoxy thickness. Good luck. Quote Link to comment Share on other sites More sharing options...
shercoben12 Posted January 4, 2013 Report Share Posted January 4, 2013 where would you buy cranks cases from? i bet there are really expensive! Quote Link to comment Share on other sites More sharing options...
johnnyboxer Posted January 4, 2013 Report Share Posted January 4, 2013 (edited) where would you buy cranks cases from? Try Gas Gas, they make them and they sell bits Edited January 4, 2013 by johnnyboxer 1 Quote Link to comment Share on other sites More sharing options...
sting32 Posted January 6, 2013 Report Share Posted January 6, 2013 (edited) Doesn't broken cases mean that there has to be a problem with the frame or something?? Im just guessing, becuase I dont think the engine can possibly NOT stand the stresses, it would get for normal use, unless or if the other parts are broken/bent/loose and not doing thier job. I would as a non_ structural_engineer qualifications, think the engine is bolted into place, and only is slightly a "stress" member in the configuration of frame and skidplate along with engine. I have had the engines out of a few of my Pro bikes, but nothing since the 08 RAGA 300, (prototype for the round tube frames if you recall). It has had the engine out of it. I mention this, because from Montesa's to Gas Gas, It is not uncommon to be hard to (if you) take skid plate off, then get it back on, because of the forces that happen on skidplate can tweak and cause things to shift when you unbolt... but never have I had a problem removing the engine and getting it back in (as long as you dont losen the skidplate, I guess. Something must be wrong, so I guess I would have to insist that something else is wrong that is not being corrected, for the frame to break the engine cases, IMHO. Unless of course, Evil Knievel's evil twin brother, is setting jump records on this thing? Maybe the skidplate is loose or something wrong, or too much dirt built up between rubber and engine and skidplate, or there is a broken part somewhere besides the engine cases? Edited January 6, 2013 by sting32 1 Quote Link to comment Share on other sites More sharing options...
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