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Crankcase White Smoke
I have a 1980 Special less than 20K miles that makes quit a bit of white smoke from the crankcase breather.
This is my first XS1100 and I love it. I’ve owned many bikes and maintained them myself for over 25 years. I have read a bunch of the posts, which were a huge help, but can't find one that matches my conditions.
Here are the details. I purchased the bike in a non-running (disaster) state last fall. The bike had not been run in God only knows how long. I changed the oil and filter and cleaned the tank before even turning it over. The first time I poured gas in the tank and opened the petcocks, gas poured from the carbs. I'm thinking "no big deal, stuck floats." I pulled the carbs took off the bowls and soaked everything down with carb cleaner. I gently worked the parts to free them. (I did not pull the jets or diaphragms.) After cleaning everything, re-assembling the carbs, I hooked up some temp fuel line and filled them with gas, (off of the bike), to make sure they did not leak. I changed the oil again just to make sure it was not full of fuel. I removed the cracked airbox and replaced it with pod filters. I cut the top inch off of the crankcase breather hose and installed a pod like metal air filter and secured it to the underside of the frame near the rear of the gas tank. Pulled, cleaned and gapped the plugs. Replaced the battery. Washed out the gas tank. (Yes, with fuel.) Removed the octopus and replaced it with new fuel line and inline filters (Pics to share later, I did this different from anyone else and am pleased with the results). It was time to start the bike. After a couple of coughs and wheezes it roared to life. It ran very, very rough and sounded like it had a bad valve. I pulled the plugs and checked the cylinder pressures and they were within acceptable range. I browsed the forum and discovered that I had connected the vacuum advance to the wrong cylinder. I corrected the problem, fired up the bike and it ran much better. Still very rough but no more valve sound, acceptable considering how long it sat. I figured that if I ran it some it might loosen up and get better. I noticed that as soon as it got up to operating temp it would start to make white smoke from the crankcase breather. No exhaust smoke. It only smokes enough so that while you are underway it is not noticeable. When you stop at a light, there is a steady flow of white smoke. I put a small cotton tennis sock over the metal breather filter to see if some additional back pressure might help but it did not. I tried a pcv valve which made it sound like a turbine engine, I took it off right away because I was scared I might blow the oil seals. As suggested, I have been running Seafoam in the gas to see if it will get any better. The more I ride it, the smoother it gets. But it still smokes the same. I have noticed that the number one spark plug gets a lot of carbon buildup like it's running way rich. Numbers 2, 3, 4 look perfect. I used an inline spark tester and cylinder 1 did light up. The header for cylinder 1 heats like the rest so I assume it's firing. It uses a little oil so I added some heavy duty oil stabilizer but it made no difference.
Fuel consumption seems high. I average mid to high 20s. Since I have no idea of what normal is for this bike I'm just guessing it's off. I did a ride last weekend and made it about 90miles before the low fuel light came on. I have noticed that the idle is inconsistent. Sometimes I stop and it idles where it should, other times it idles high. If I slip the clutch just enough to pull down the engine speed, it slows to the normal idle. Power delivery is smooth across the entire range. It does not miss or backfire under load. It starts fine but is cold natured. It misses and sputters for a minute or so as it warms. Once it reaches operating temp it is just fine. (I can't complain, at 44 I do the same thing when I wake)
So there you have it. I hope someone has an idea because short of tearing down the motor to check the rings, walls and valves, I'm stumped.
This is my first XS1100 and I love it. I’ve owned many bikes and maintained them myself for over 25 years. I have read a bunch of the posts, which were a huge help, but can't find one that matches my conditions.
Here are the details. I purchased the bike in a non-running (disaster) state last fall. The bike had not been run in God only knows how long. I changed the oil and filter and cleaned the tank before even turning it over. The first time I poured gas in the tank and opened the petcocks, gas poured from the carbs. I'm thinking "no big deal, stuck floats." I pulled the carbs took off the bowls and soaked everything down with carb cleaner. I gently worked the parts to free them. (I did not pull the jets or diaphragms.) After cleaning everything, re-assembling the carbs, I hooked up some temp fuel line and filled them with gas, (off of the bike), to make sure they did not leak. I changed the oil again just to make sure it was not full of fuel. I removed the cracked airbox and replaced it with pod filters. I cut the top inch off of the crankcase breather hose and installed a pod like metal air filter and secured it to the underside of the frame near the rear of the gas tank. Pulled, cleaned and gapped the plugs. Replaced the battery. Washed out the gas tank. (Yes, with fuel.) Removed the octopus and replaced it with new fuel line and inline filters (Pics to share later, I did this different from anyone else and am pleased with the results). It was time to start the bike. After a couple of coughs and wheezes it roared to life. It ran very, very rough and sounded like it had a bad valve. I pulled the plugs and checked the cylinder pressures and they were within acceptable range. I browsed the forum and discovered that I had connected the vacuum advance to the wrong cylinder. I corrected the problem, fired up the bike and it ran much better. Still very rough but no more valve sound, acceptable considering how long it sat. I figured that if I ran it some it might loosen up and get better. I noticed that as soon as it got up to operating temp it would start to make white smoke from the crankcase breather. No exhaust smoke. It only smokes enough so that while you are underway it is not noticeable. When you stop at a light, there is a steady flow of white smoke. I put a small cotton tennis sock over the metal breather filter to see if some additional back pressure might help but it did not. I tried a pcv valve which made it sound like a turbine engine, I took it off right away because I was scared I might blow the oil seals. As suggested, I have been running Seafoam in the gas to see if it will get any better. The more I ride it, the smoother it gets. But it still smokes the same. I have noticed that the number one spark plug gets a lot of carbon buildup like it's running way rich. Numbers 2, 3, 4 look perfect. I used an inline spark tester and cylinder 1 did light up. The header for cylinder 1 heats like the rest so I assume it's firing. It uses a little oil so I added some heavy duty oil stabilizer but it made no difference.
Fuel consumption seems high. I average mid to high 20s. Since I have no idea of what normal is for this bike I'm just guessing it's off. I did a ride last weekend and made it about 90miles before the low fuel light came on. I have noticed that the idle is inconsistent. Sometimes I stop and it idles where it should, other times it idles high. If I slip the clutch just enough to pull down the engine speed, it slows to the normal idle. Power delivery is smooth across the entire range. It does not miss or backfire under load. It starts fine but is cold natured. It misses and sputters for a minute or so as it warms. Once it reaches operating temp it is just fine. (I can't complain, at 44 I do the same thing when I wake)
So there you have it. I hope someone has an idea because short of tearing down the motor to check the rings, walls and valves, I'm stumped.
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