Jason110571 Posted November 2, 2011 Share Posted November 2, 2011 hi and thank you who helped and looked at my last problem where would i be if it wasnt for you guys willing to help here gose im trying to do my yamaha dt 175 mx uk model year 1980 up to bring it back to its former glory when i bought the bike there was a horrible noise coming from engine i was told it was crank shalf bearing so i split the engine down and replace with new bearings and also new oil seals all round put the engine back together but now the noise has stopped but ive got loads of white/grey smoke and i mean loads, on tick over and when i rev coming out of the exhaust pipe and a bit of black oil or fuel around the back box also the engine is having problems ticking over i popped down the local bike garage where i live who i bought the crank shalf bearings and oil seals and he told me oil was getting in throught the crank shalf seal so striped engine back down like he said and renewed oil seals again put back together but still the same he told me he would do it for a cost of £550 ouch i felt what a lot of money i didnt change anything else only crank shalf bearings oil seals and head gastet it all went back quite easy and there wasnt nothing left over ive set the carb thats fine can any body help me with this twise ive stripped engine down and feel gutted before i touched the engine there wasnt no smoke and would tick over fine and run well but it was just the noise this was my first time in doing something like this but it was easy project i thought i did follow the work shop manual 100 percent of the way thank you in taking the time in reading this kind regards jay Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 2, 2011 Moderator Share Posted November 2, 2011 jay it sounds like the crank seal on the right of the bike, When this seal passes the engine oil gets into the crankase as so gets burned producing the thick smoke, its not a full strip...not even an engine out job but you will need a clutch holding tool to hold the engine still so you can undo the nut on the primary gear altrenatively you will need to remove the cylinder piston and head and place a rod (1/2 inch drive extension bar) through the small end onto wooden blocks so the small end is approx 1/2 stroke aside from this is it possible you forgot to fit the 'O' ring under the spacer behind the primary gear when you worked on the bike last? Link to comment Share on other sites More sharing options...
Jason110571 Posted November 2, 2011 Author Share Posted November 2, 2011 jay it sounds like the crank seal on the right of the bike, When this seal passes the engine oil gets into the crankase as so gets burned producing the thick smoke, its not a full strip...not even an engine out job but you will need a clutch holding tool to hold the engine still so you can undo the nut on the primary gear altrenatively you will need to remove the cylinder piston and head and place a rod (1/2 inch drive extension bar) through the small end onto wooden blocks so the small end is approx 1/2 stroke hi and thank you in taking the time in reading my problem ive changed the crank seal twise now and its still doing it i havent took the bike out for a run since the crank shalf bearings and seal where replaced i just started it up from cold and lefted it on tick over do you think the bike could do with a good thrashing to clear the engine out like ive said this is my first project with doing something like this but now its bugging me is there a way of putting oils seals in, the crank shalf seal on the right hand side it gose in level to the engine casing should the seal go deeper than that i dont wont to push to hard in case i brake the seal when i pushed the seal in the bottem did go right in further than the top at first but now its level all round with the casing thank you so much for your help kind regards jay Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 2, 2011 Moderator Share Posted November 2, 2011 yeah take it for a good run before coming to any conclusions you did remember the 'O' ring?? seals are open side in closed side out Link to comment Share on other sites More sharing options...
Jason110571 Posted November 2, 2011 Author Share Posted November 2, 2011 yeah take it for a good run before coming to any conclusions you did remember the 'O' ring?? seals are open side in closed side out i didnt touch a o ring the only o ring there was was a little round rubber wich fits into the stem if that makes sence but thats there and the oil seal are both open sided you can see well it looks like a round spring iver side of the oil seal i will say that looking at the oil seal one side is opened larger than the other side so the larger side gose in first towards the crank bearing sorry to be a right pain Link to comment Share on other sites More sharing options...
YPVS TONE Posted November 2, 2011 Share Posted November 2, 2011 Hi Jay Does the RH oil seal lips contact on a collar or is it part of the primary gear. If you strip it again check where the seal lips contact to make sure there isn't a groove in the collar / primary gear. Tony Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 2, 2011 Moderator Share Posted November 2, 2011 Hi Jay Does the RH oil seal lips contact on a collar or is it part of the primary gear. If you strip it again check where the seal lips contact to make sure there isn't a groove in the collar / primary gear. Tony yeah Tony it seals onto a spacer collar and under the collar on the crank is the 'O' ring but i just dont know why jason cant go for a ride and confirm if there is actually a problem or not! it seems its just been built and gone nowhere from whats been said so far. Link to comment Share on other sites More sharing options...
Jason110571 Posted November 2, 2011 Author Share Posted November 2, 2011 Hi Jay Does the RH oil seal lips contact on a collar or is it part of the primary gear. If you strip it again check where the seal lips contact to make sure there isn't a groove in the collar / primary gear. Tony there is a groove in the collar thats where the o ring gose ive stripped it down again and checked it all it all looked fine put it all back together filled up with oil and started it up and there wasnt no smoke at all i was so happy reved it a little smoke but when i took it out up the road there was a lot of smoke ive just been told it could be head gasket gone Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 2, 2011 Moderator Share Posted November 2, 2011 take it for a ride smoke is normal when cold Link to comment Share on other sites More sharing options...
Jason110571 Posted November 2, 2011 Author Share Posted November 2, 2011 yeah Tony it seals onto a spacer collar and under the collar on the crank is the 'O' ring but i just dont know why jason cant go for a ride and confirm if there is actually a problem or not! it seems its just been built and gone nowhere from whats been said so far. sorry if ive said it rong and you didnt understand what i said i dont understand myself sometimes and its my first project right ive took the bike for a ride like you have said and belted it up the road i got it up to 60 miles an hour and by god i couldnt see a thing behind me with smoke but it has stopped smoking at tick over but before it was smoking bad on tick over it dosnt smoke when you ride slow i must point out i didnt change the o ring when i changed the crank bearing and oil seals ive got another 175 engine which has big problems and i looked on the old engine and took the o ring of i no you shouldnt but worth a try and put o ring on my engine i then put it all back together and then started engine on tick over it stopped smoking on tick over even when you rev it it dosnt smoke but dose smoke bad when riding realy bad kind regards jay Link to comment Share on other sites More sharing options...
YPVS TONE Posted November 2, 2011 Share Posted November 2, 2011 I would do what og says and give it a good run. Did you put a lot of oil on the bearings and piston and bore when you reassembled it .If so it is proably just this being burn't off after it has built up in the crankcase especially at high rpm. Just keep an eye on the gearbox oil as if it is burning it to that extent the level will drop. Have you checked the oil pump cable setting to make sure it is set right and make sure the oil pump cable hasn't pulled out of the junction box or are you using premix in the petrol tank ?. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 2, 2011 Moderator Share Posted November 2, 2011 yeah but until its had a decent ride say 10 miles i'll reserve judgement, it needs the long ride and to be up to temp for a while before you can say if you have a problem or not...its been off the road and under maintanance after all. I would expect it to be a bit smoky at first...thats my opinion anyway for what it's worth Link to comment Share on other sites More sharing options...
Jason110571 Posted November 2, 2011 Author Share Posted November 2, 2011 I would do what og says and give it a good run. Did you put a lot of oil on the bearings and piston and bore when you reassembled it .If so it is proably just this being burn't off after it has built up in the crankcase especially at high rpm. Just keep an eye on the gearbox oil as if it is burning it to that extent the level will drop. Have you checked the oil pump cable setting to make sure it is set right and make sure the oil pump cable hasn't pulled out of the junction box or are you using premix in the petrol tank ?. hi yes quite a bit went down i no it was stupid of me and yes i need a rollocking for doing it. i will take it for a long ride tomorow and see how it gose and i will keep an eye on the engine level to the oil pump cable is all in contact. i just carnt understand since ive changed the o ring from the other engine it dosnt smoke on tick over or when i rev it but i will let you no tomorow how i get on im so greatfull for your help Link to comment Share on other sites More sharing options...
Jason110571 Posted November 2, 2011 Author Share Posted November 2, 2011 yeah but until its had a decent ride say 10 miles i'll reserve judgement, it needs the long ride and to be up to temp for a while before you can say if you have a problem or not...its been off the road and under maintanance after all. I would expect it to be a bit smoky at first...thats my opinion anyway for what it's worth thank you for your advice i will take it for a long run tomorow. i just carnt understand since ive put the o ring from the other bike on to mine like ive said i shouldnt do that, it stopped smoking on tick over and when i reved it but i will do what you all say and take it for a long run im so greatfull for your help Link to comment Share on other sites More sharing options...
NE0 Posted November 3, 2011 Share Posted November 3, 2011 I've just done exactly the same as you on my 175MX and put it all back together without a problem. (although I've stripped and rebuilt hundreds of engines in my time) I renewed the main bearings and the gearbox bearings, all the seals and rings. Started 1st time and no smoke! other than the initial smoke on priming the oil pump. As you're aware from the posts, oil has to remain in the gearbox and not get into the crank area. Whilst there is no gasket between the 2 halves, I assume you put "instant gasket" on the exposed face before reassembly. (I took photos of every stage to help others). Plus..... I'm also in West Sussex!! Link to comment Share on other sites More sharing options...
Jason110571 Posted November 3, 2011 Author Share Posted November 3, 2011 I've just done exactly the same as you on my 175MX and put it all back together without a problem. (although I've stripped and rebuilt hundreds of engines in my time) I renewed the main bearings and the gearbox bearings, all the seals and rings. Started 1st time and no smoke! other than the initial smoke on priming the oil pump. As you're aware from the posts, oil has to remain in the gearbox and not get into the crank area. Whilst there is no gasket between the 2 halves, I assume you put "instant gasket" on the exposed face before reassembly. (I took photos of every stage to help others). Plus..... I'm also in West Sussex!! hi thanks for the advice this engine now has stopped smoking and runs very well now ive got another dt 175 mx engine but its in bits and been split how much for you to rebuild that one i would never do it again but like ive said it was my first time and my last if you could let me no how much you would charge my mobile is 07515403879 ive got new gear selctors two new crankbearings and head gasket oil seals so on could you let me no kind regards jay Link to comment Share on other sites More sharing options...
Jason110571 Posted November 3, 2011 Author Share Posted November 3, 2011 hi and thank you for all your help i changed the o ring plus put another new crank sharf seal on then put it all back together and took it for a 5 mile ride yes i got soaking wet with the rain but i wasnt bothered in that knowing that the bike had stopped smoking like i said it was my first time on trying something like this and my blimming last but with all your help i got there in the end thank you all so much kind regards jay Link to comment Share on other sites More sharing options...
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