webi Posted July 18, 2010 Share Posted July 18, 2010 my bike has started smoking white smoke not to much but constant it is a yamaha yb100 it is a single cylinder air cooled bike i took the gearbox oil out and it smelt a little of petrol should it smell like this? and the plug was black you couldnt see wet oil but if you touched it you would have oil on your hand the bike starts great first kick every time even in the morning. thanks for the help Link to comment Share on other sites More sharing options...
Moderator mervin Posted July 18, 2010 Moderator Share Posted July 18, 2010 sound like the gearbox side crankseal is going if you can smell fuel in the gearbox oil. and it will be sucking in gearbox oil as well,best to do both sides while you are at it though Link to comment Share on other sites More sharing options...
webi Posted July 18, 2010 Author Share Posted July 18, 2010 sound like the gearbox side crankseal is going if you can smell fuel in the gearbox oil. and it will be sucking in gearbox oil as well,best to do both sides while you are at it though are crankseals a big job and will i have to split the crank i have a magneto/flywheel puller? Link to comment Share on other sites More sharing options...
2 Wheels Posted July 19, 2010 Share Posted July 19, 2010 Webi,,,,, Before ya go at the crank seals. Try and make your carb a bit more lean, then go for a good hard run on the bike for half hour, see will the smoke clear. Check the plug then and see if its still oily. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted July 19, 2010 Moderator Share Posted July 19, 2010 Why re-start the topic? Link to comment Share on other sites More sharing options...
webi Posted July 19, 2010 Author Share Posted July 19, 2010 Webi,,,,, Before ya go at the crank seals. Try and make your carb a bit more lean, then go for a good hard run on the bike for half hour, see will the smoke clear. Check the plug then and see if its still oily. only thing with this is that it wasnt smoking when i first got it it just started when i took it for a ride and it got quite hot as i could smell it Link to comment Share on other sites More sharing options...
Moderator Cynic Posted July 19, 2010 Moderator Share Posted July 19, 2010 only thing with this is that it wasnt smoking when i first got it it just started when i took it for a ride and it got quite hot as i could smell it Go out, fill the tank, and ride the balls off it till you run out of fuel. Chances are it will run great or die. But it will settle it. I recon its full of shit. I've had 2 2strokes turn into smoke machines the first time they get ridden hard. Did neither of em any harm. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 19, 2010 Moderator Share Posted July 19, 2010 And before this thrash check yor gearbox oil. And after this thrash check it again. Did you do the gearbox vent bubbles test I mentioned then that is a good indicator of RH seal failure and is easy to do Link to comment Share on other sites More sharing options...
webi Posted July 19, 2010 Author Share Posted July 19, 2010 Go out, fill the tank, and ride the balls off it till you run out of fuel. Chances are it will run great or die. But it will settle it. I recon its full of shit. I've had 2 2strokes turn into smoke machines the first time they get ridden hard. Did neither of em any harm. ok will try this thanks i heard that if your crankseals have gone it makes the bike hard to start but mine starts easily without any choke but takes a second for the revs to respond so i wonder if it is crank seals or running to rich maybe? Link to comment Share on other sites More sharing options...
webi Posted July 19, 2010 Author Share Posted July 19, 2010 And before this thrash check yor gearbox oil. And after this thrash check it again. Did you do the gearbox vent bubbles test I mentioned then that is a good indicator of RH seal failure and is easy to do i cant find the right tube all i can find is the carb overflow Link to comment Share on other sites More sharing options...
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