kidneybeaner Posted November 4, 2008 Share Posted November 4, 2008 Hi all, I've bought a replacement engine for my J reg SR 125 which I'm going to recondition and then swap over during the next couple of months - the replacement is one that has done about 10k. If anyone has any pointers or advice to give me at an early stage I'd appreciate it - at the moment I'm full of enthusiasm but don't want to do anything stupid in the first 5 minutes! The job therefore is: Recondition replacement engine, fit new gaskets etc. Remove old engine Fit replacement engine Any advice, however small is appreciated. Thanks! Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 4, 2008 Moderator Share Posted November 4, 2008 Hi all, I've bought a replacement engine for my J reg SR 125 which I'm going to recondition and then swap over during the next couple of months - the replacement is one that has done about 10k. If anyone has any pointers or advice to give me at an early stage I'd appreciate it - at the moment I'm full of enthusiasm but don't want to do anything stupid in the first 5 minutes! The job therefore is: Recondition replacement engine, fit new gaskets etc. Remove old engine Fit replacement engine Any advice, however small is appreciated. Thanks! Hi and welcome, First start with a workshop manual, there will be lots of good info in there! Link to comment Share on other sites More sharing options...
JimR Posted November 8, 2008 Share Posted November 8, 2008 Hi all, I've bought a replacement engine for my J reg SR 125 which I'm going to recondition and then swap over during the next couple of months - the replacement is one that has done about 10k. If anyone has any pointers or advice to give me at an early stage I'd appreciate it - at the moment I'm full of enthusiasm but don't want to do anything stupid in the first 5 minutes! The job therefore is: Recondition replacement engine, fit new gaskets etc. Remove old engine Fit replacement engine Any advice, however small is appreciated. Thanks! at 10k what is it going to need ? .. a cam chain (always worth a new one if you dont know the history), a bit of a clean, oil & filter change. Also you may want to set valve clearences (easy with the motor on the bench). pulling the motor to bits could be quite costly and you gain nothing bar peace of mind that the engine is A1 (which I guess you will find out after the strip down). If the old engine is showing signs of wear I would fit the replacement and rebuild the original then you may be striping the engine for some good reason ! either way when you do the oil/filter change dont forget to 'bleed' the system regards Jim Link to comment Share on other sites More sharing options...
kidneybeaner Posted May 12, 2009 Author Share Posted May 12, 2009 So after much faffing through the winter months I succeeded in swapping out my old SR125 engine for the replacement. The lowest moment was when I was about to install the rebuilt engine into the frame when I noted that the previous owner had sheared off one of the exhaust bracket bolts inside the engine casing - I tried in vain to remove said bolt (including swallowing my pride and lugging the whole lot to my friendly bike garage) but it was just too tricky. I therefore removed the whole top end of the new engine and replaced the whole section with the exhaust port in. Cue lots of exciting moments when I screwed up the timing between the top and bottom ends of the engine. After much work (and fiddling) I succeeded in installing the reconditioned engine and low and behold, it fired up and worked straight away! I have rarely been as proud as I was that day. But..... An oil leak was spotted on the left hand side of the crank in the lower area - I think it is almost certainly where the gasket between the crank and the piston barrel would sit although I'm not 100% on this. Before you ask, yes I replaced all the gaskets and yes, I've torqued all the bolts up correctly - still the oil leak appears. Does anyone have any experience of this and can anyone suggest any solutions? I'm nervous of overtightening any of the bolts as I had a main engine bolt snap when rebuilding the engine (old I guess, hadn't hit correct torque) and definitely don't want to go through the same thing again.... Link to comment Share on other sites More sharing options...
Moderator drewpy Posted May 12, 2009 Moderator Share Posted May 12, 2009 So after much faffing through the winter months I succeeded in swapping out my old SR125 engine for the replacement. The lowest moment was when I was about to install the rebuilt engine into the frame when I noted that the previous owner had sheared off one of the exhaust bracket bolts inside the engine casing - I tried in vain to remove said bolt (including swallowing my pride and lugging the whole lot to my friendly bike garage) but it was just too tricky. I weld a nut over the hole and the metal flows onto the sheared stud. the heat in all this loosens the stud as well and use a spanner to take out the stud. I have done this quite a few times as I restored a classic car as well as bikes and has never failed me. not sure about you leak though, maybe some one has previuosly used that point as a lever to take off the barrell, thus creating the problem!! Link to comment Share on other sites More sharing options...
JimR Posted May 12, 2009 Share Posted May 12, 2009 I weld a nut over the hole and the metal flows onto the sheared stud. the heat in all this loosens the stud as well and use a spanner to take out the stud. I have done this quite a few times as I restored a classic car as well as bikes and has never failed me. not sure about you leak though, maybe some one has previuosly used that point as a lever to take off the barrell, thus creating the problem!! or perhaps it some old base gaskit left onone of the faces ? Regards Jim Link to comment Share on other sites More sharing options...
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