webi Posted July 17, 2010 Share Posted July 17, 2010 hello i have a 1988 yamaha yb100 deluxe i took it out today and ride it for quite a while i noticed it was smoking out of the exhaust alot and the engine smelt hot i wondered if anyone could tell me what this could be i was also running lowish on petrol the smoke was white Link to comment Share on other sites More sharing options...
2 Wheels Posted July 17, 2010 Share Posted July 17, 2010 Doesnt sound that bad really. Unless: Is it overheating? Is the white smoke there all the time? How much smoke? Is this an air cooled bike? Was it like this all the time? Give more details about the bike and its history !!!!!!!!!!!!!! Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 17, 2010 Moderator Share Posted July 17, 2010 Yes 2wheels it's an aircooled two stroke. White smoke causes concern though, could be a sign that it needs new crank seals, white smoke can be as a result of burning gearbox oil...ie right side seal passing. Watch for gearbox oil level falling and/or smelling of fuel. Its an old bike anyway so might just be best to change them both. Link to comment Share on other sites More sharing options...
webi Posted July 17, 2010 Author Share Posted July 17, 2010 Yes 2wheels it's an aircooled two stroke. White smoke causes concern though, could be a sign that it needs new crank seals, white smoke can be as a result of burning gearbox oil...ie right side seal passing. Watch for gearbox oil level falling and/or smelling of fuel. Its an old bike anyway so might just be best to change them both. the engine smelt very hot the white smoke is there always but more when i rev it there is less smoke when it is cold and i can smell fuel Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 17, 2010 Moderator Share Posted July 17, 2010 it seems it needs new crank seals to me, you smell fuel in the gear oil? Link to comment Share on other sites More sharing options...
webi Posted July 17, 2010 Author Share Posted July 17, 2010 it seems it needs new crank seals to me, you smell fuel in the gear oil? will have a smell tomorrow in the gear oil and let you know is replacing crank seals a expensive/hard job and will the new seals have to be run in? edit: i also think there was alot of oil on the spark plug if that helps Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 17, 2010 Moderator Share Posted July 17, 2010 It all depends on what tools you have and how competent you are. you will need at least a magneto puller, and decent screwdriver to remove the side cases screws (has to be a good fitting one) along with a good socket set and a reasonable tool kit. and i would be guessing if i said it can be done without totally stripping the engine...but that's my guess for what it's worth. I dont know how expensive it would be to have done at a garage. Link to comment Share on other sites More sharing options...
webi Posted July 17, 2010 Author Share Posted July 17, 2010 It all depends on what tools you have and how competent you are. you will need at least a magneto puller, and decent screwdriver to remove the side cases screws (has to be a good fitting one) along with a good socket set and a reasonable tool kit. and i would be guessing if i said it can be done without totally stripping the engine...but that's my guess for what it's worth. I dont know how expensive it would be to have done at a garage. ok thanks for your help will smell the gearbox oil tomorrow and see another thing you could help me with if you like is that the bike starts first kick every time even on a cold morning without any choke but it wont tick over im wondering if it is running to rich? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 17, 2010 Moderator Share Posted July 17, 2010 ok thanks for your help will smell the gearbox oil tomorrow and see another thing you could help me with if you like is that the bike starts first kick every time even on a cold morning without any choke but it wont tick over im wondering if it is running to rich? naturally if it's burning gearbox oil it will badly affect the running of the engine so if this is the case it's no use bothering with carb settings. as a test take the gearbox breather pipe, pour some white spirit into a clean jar and place the end of the breather in the jar also, Start the engine and look for bubbles in the jar ...a sure sign of a bad seal Link to comment Share on other sites More sharing options...
webi Posted July 17, 2010 Author Share Posted July 17, 2010 naturally if it's burning gearbox oil it will badly affect the running of the engine so if this is the case it's no use bothering with carb settings. as a test take the gearbox breather pipe, pour some white spirit into a clean jar and place the end of the breather in the jar also, Start the engine and look for bubbles in the jar ...a sure sign of a bad seal nice one thanks mate will do that tomorrow i wouldnt say the bike is running bad but it was when i bought it but i fixed that because the ignition points where closed completly i was surprised the bike even started is the gearbox breather pipe a little black pipe near the back brake pedal thing xD? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 17, 2010 Moderator Share Posted July 17, 2010 is the gearbox breather pipe a little black pipe near the back brake pedal thing xD? Dont know the bike well enough to say, it no doubt is black and will attach to a spigot on top of the engine, somewhere behind the cylinder, I expect there will be only one like this. Link to comment Share on other sites More sharing options...
webi Posted July 17, 2010 Author Share Posted July 17, 2010 Dont know the bike well enough to say, it no doubt is black and will attach to a spigot on top of the engine, somewhere behind the cylinder, I expect there will be only one like this. ok thanks for all your help top man Link to comment Share on other sites More sharing options...
Moderator Cynic Posted July 18, 2010 Moderator Share Posted July 18, 2010 Running bad when you bought it, how long ago? Crank seals invariably make the bike a cow to start. Have you checked the airbox for moisture/blockage/dirtyfilter and the exhaust to see just how much junk is inside. If this little YB has spent its life chugging through traffic and you have just scared it to death with a 50mile blast all of the above is likely. Link to comment Share on other sites More sharing options...
webi Posted July 18, 2010 Author Share Posted July 18, 2010 Running bad when you bought it, how long ago? Crank seals invariably make the bike a cow to start. Have you checked the airbox for moisture/blockage/dirtyfilter and the exhaust to see just how much junk is inside. If this little YB has spent its life chugging through traffic and you have just scared it to death with a 50mile blast all of the above is likely. bought it about 1 week ago the bike took 4 kicks this morning to start but it started nicely i forgot to say this before but usually when i start it it takes around about 3 seconds for the revs to come on Link to comment Share on other sites More sharing options...
2 Wheels Posted July 18, 2010 Share Posted July 18, 2010 Doesnt sound that bad really. Unless: Is it overheating? Is the white smoke there all the time? How much smoke? Is this an air cooled bike? Was it like this all the time? Give more details about the bike and its history !!!!!!!!!!!!!! Yes 2wheels it's an aircooled two stroke. White smoke causes concern though, could be a sign that it needs new crank seals, white smoke can be as a result of burning gearbox oil...ie right side seal passing. Watch for gearbox oil level falling and/or smelling of fuel. Its an old bike anyway so might just be best to change them both. Running bad when you bought it, how long ago? Crank seals invariably make the bike a cow to start. Have you checked the airbox for moisture/blockage/dirtyfilter and the exhaust to see just how much junk is inside. If this little YB has spent its life chugging through traffic and you have just scared it to death with a 50mile blast all of the above is likely. Think about and check-out all the points that are in blue. What have ya done to the bike since ya have got it? When started it will take a min to warm up, then after its warm stop it, let cool down a bit, then check oil level---make a note of where it is at. Will the bike idle, if so go for a 15min spin, when ya get back see will it idle ok----if not then it might b slightly overheating. Check oil 2 see did it drop any from where it was. Is the oil white and smelling of fuel now. Link to comment Share on other sites More sharing options...
webi Posted July 18, 2010 Author Share Posted July 18, 2010 Think about and check-out all the points that are in blue. What have ya done to the bike since ya have got it? When started it will take a min to warm up, then after its warm stop it, let cool down a bit, then check oil level---make a note of where it is at. Will the bike idle, if so go for a 15min spin, when ya get back see will it idle ok----if not then it might b slightly overheating. Check oil 2 see did it drop any from where it was. Is the oil white and smelling of fuel now. bike will not idle at all since ive gotten it ive put in some 2 stroke oil the brand is called sthil or something like that Link to comment Share on other sites More sharing options...
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