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Why is my Kawa Vulkan choking on oil in the breathers. Just has
3,500 miles (supposedly)!? Noticed oil in the air intake and won't rev past 5,000 rpm. Was alright yesterday. Just got the bike 2 weeks ago... Anyone familiar.... 4 cyl DOHC 750???

What Vulcan is a 4 cyl? I thought all were V-Twins?

What year? Are you sure it's a Vulcan?

Mmmm 3500 miles. Sounds like you got lied to. The oil blowing back is caused by two ailments. First the intake valve guide seal is leaking or the rings are excessively worn. Second for the oil to get blown back through the carburetor your valve clearance may be too tight or your valve or valve seats may be worn. (does the bike smoke?) You may want to do a compression check.

Good Luck

Oil is probably not being blown back through the carb. The most likely source is the crankcase ventilation system which will have a hose running from the crankcase to the airbox.

Bad rings will cause excess crankcase pressure and could blow oil out the breather hose. The more common cause is an excessive amount of oil in the crankcase.

If it's not the crankcase vent...is there WAY too much oil in the crankcase? Is your air filter one of the kind that is supposed to be oiled?

Good point Flynrider. Overfilled crankcase oil, probably the most likely especially with low miles like he stated. That crankcase vent tube vents directly into the airbox so the whole airbox and air filter should be oily as well. Sparked - Did you figure it out?

The Viking

flynrider wrote:Oil is probably not being blown back through the carb. The most likely source is the crankcase ventilation system which will have a hose running from the crankcase to the airbox.

Bad rings will cause excess crankcase pressure and could blow oil out the breather hose. The more common cause is an excessive amount of oil in the crankcase.

If it's coming out through the breather then it's not blowing back through the carb.

Three most probable causes in order:
1) oil overfilled
2) crankcase breather seal has dried out and is leaking
3) piston rings/cylinders are worn out

Sparked wrote: ↑Fri Oct 24, 2008 11:57 am Why is my Kawa Vulkan choking on oil in the breathers. Just has 3,500 miles (supposedly)!? Noticed oil in the air intake and won't rev past 5,000 rpm. Was alright yesterday. Just got the bike 2 weeks ago... Anyone familiar.... 4 cyl DOHC 750???

I think excessive blow-by occurs when combustion gases leak past the piston rings into the crankcase, causing an increase in pressure. This can result in oil being pushed into the air intake and breathers.

The oil in the intake and choking through the breathers is definitely a sign that something’s off. First thing I’d check is the crankcase ventilation system—the breather hose or valve could be clogged or restricted. If there's pressure building up in the crankcase, it could force oil into the intake and mess with the revs.

Another thing to look at is whether the oil is overfilled. If there's too much oil, it can get sucked into the intake through the breathers, especially at higher revs. Definitely double-check the oil level and make sure it’s right where it should be.

It could also be an issue with worn piston rings or valve seals, which might cause too much pressure in the crankcase, pushing oil out through the breathers.

Since you just got the bike, it’s worth asking the previous owner if they did any maintenance recently or if there’s something odd going on under the hood.