Oil in my air filter!!!!!!!

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Sparked
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Oil in my air filter!!!!!!!

#1 Unread post by Sparked » Fri Oct 24, 2008 5:57 pm

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???

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mydlyfkryzis
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#2 Unread post by mydlyfkryzis » Fri Oct 24, 2008 9:12 pm

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

What year? Are you sure it's a Vulcan?
Richard - Fully Dressed

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Against.Da.Grain
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Yeah VN 750 is a Twin

#3 Unread post by Against.Da.Grain » Tue Nov 04, 2008 8:50 am

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.

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#4 Unread post by flynrider » Tue Nov 04, 2008 2:57 pm

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.
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#5 Unread post by coffee_brake » Tue Nov 04, 2008 9:50 pm

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?
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Ah yes good point.

#6 Unread post by Against.Da.Grain » Thu Nov 06, 2008 11:47 am

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?

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#7 Unread post by Sev » Sun Dec 14, 2008 2:51 am

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
Of course I'm generalizing from a single example here, but everyone does that. At least I do.

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