sierrafox17 Posted April 3, 2009 Share Posted April 3, 2009 hey all, my 78 dt 175 died after a day of biking, and we broke it down and found the piston and gaskets were fine. what we do see it that the connecting rod is next to locked up, so its really hard to kick over, even with the piston out and in the open. so the bearings went? we may just place the whole bottom end but any insight will help thanks everyone Link to comment Share on other sites More sharing options...
Moderator Cynic Posted April 3, 2009 Moderator Share Posted April 3, 2009 hey all, my 78 dt 175 died after a day of biking, and we broke it down and found the piston and gaskets were fine. what we do see it that the connecting rod is next to locked up, so its really hard to kick over, even with the piston out and in the open. so the bearings went? we may just place the whole bottom end but any insight will help thanks everyone Unlucky, if the top end is ok then it is likely wear that has done for the bearings rather than failure of lube as the piston would sieze before the bearings, trouble is no matter what bearings have gone you are going to be spliting the cases. Its not a massive job (relatively) and a full 'rebuild' kit cost me under 100quid and that was all genuine gaskets and seals with new main bearings and output shaft bearing with a full stainless allen engine screw set. You will need to do the output shaft bearing if for no other reason than its a complete strip to change it anyway. Fingers crossed the crank is good and its just the mains or you will need it rebuilding and thats not something you can do in the garage. Check out my thread 'DT 175 engine rebuild' to give you an idea, i'll add to it shortly i'm just waiting on parts. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 3, 2009 Moderator Share Posted April 3, 2009 Hi Rob, so you bought a carb with no spigot for oil on it? we did advise against this, it is just possible you got the pre mix strength wrong and you now have a seized big end bearing. Link to comment Share on other sites More sharing options...
Twin Shock Posted April 3, 2009 Share Posted April 3, 2009 I would go ahead and change all the crank bearings, if one is hurt they all are. Link to comment Share on other sites More sharing options...
sierrafox17 Posted April 7, 2009 Author Share Posted April 7, 2009 Hi Rob, so you bought a carb with no spigot for oil on it? we did advise against this, it is just possible you got the pre mix strength wrong and you now have a seized big end bearing. yeah you were probably dead on of course, but hey thats life. i figured if i kept the mixture rich it would be ok, but i was obviously wrong. i think im just going to give up on old bikes early, and start saving up for a newer 4 stroke. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted April 7, 2009 Moderator Share Posted April 7, 2009 yeah you were probably dead on of course, but hey thats life. i figured if i kept the mixture rich it would be ok, but i was obviously wrong. i think im just going to give up on old bikes early, and start saving up for a newer 4 stroke. They die just as fast if they are not maintained properly. Link to comment Share on other sites More sharing options...
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