oil tank vacuum

[BBP]

Is the oil tank supposed to have a slight vacuum? Every time I fill the oil tank, the sides of the tank are sucked in a little. When I open the cap, I can see the sides of the tank expand back out. The sled burns plenty of oil. Is this normal?

 

[Lake Powell]

Is the oil tank supposed to have a slight vacuum? Every time I fill the oil tank, the sides of the tank are sucked in a little. When I open the cap, I can see the sides of the tank expand back out. The sled burns plenty of oil. Is this normal?

My 19 does that also and goes thru a lot of oil. Peter

 

[kittykitty_900]

Check the duckbill valve in the oil tank cap

 

[BBP]

Check the duckbill valve in the oil tank cap

I took the cap apart & squeezed the duckbill open. Everything seemed ok. I'll ride tomorrow & see if anything changes.

 

[Rick E]

Minus the small amount of duck-bill valve restriction, the interior of the oil tank should be close to ambient aptmosheric pressure.

 

[BBP]

I checked my tank again yesterday. It still has the vacuum. I could hear the whooosh of air go in as I opened the cap. It still burned a quart of oil on Wednesdays ride.

 

[Coldfinger]

Could it be while you are riding, the tank gets warm and the air inside expands. After the tank cools it contacts. I would think the tank would allow air in and that wouldnt happen, but I don’t know…

 

[BBP]

Could it be while you are riding, the tank gets warm and the air inside expands. After the tank cools it contacts. I would think the tank would allow air in and that wouldnt happen, but I don’t know…

Could be, but every time I've checked, it was after a night in a heated shop. I'll check it again while riding.

 

[jdog1]

Not normal at all. Your burning more oil then normal also.

 

[AkSledHed]

Definitely not normal, you've got an oil line or vent clogged/pinched somewhere.