Oil tank empties into cyliders during off season

[cjheven]

Hi I have a 1994 XP that is in pretty good shape. New block was installed about 5 years ago. Ski doesn't get ridden much. For several years the oil tank has emptied into the cylinders during the off season. The oil injection has been blocked off because its old and can't be trusted. Of course the main line from the tank is still attached to the pump. I am planning on replacing the check valves. So other than the 2 check valves on the 2 small lines at the pump, is there any other way for the oil to get from the tank to the cylinders? I don't want to over look anything if I have to pull the carbs off yet again. Thanks for your help

 

[Minnetonka4me]

Umm....so how is the "main line still attached to the pump" if you have it blocked off? the check valves cant be a problem if the oil isnt pumping.

A good rule of thumb is if both cyls are getting filled, its either the check valves, or the seal on the rotory valve shaft. If its just one cylinder, its from a faulty seal on the crank. Again...just a rule of thumb. Some machines could have both seals bad.

Another theory I have is pressure build up from temp changes. When the cap is on tight the check valves hold about 2-3psi before they open. That pressure could possibly be pushing oil past the seals....as well as the bungs on the tank. Wonder why there is oil in the bottom of the hull after storage? I think this pressure is why.

I am testing the theory on my GFs 93 GTX; I have the tank cap cracked open so the pressure can escape. We will see in a month if it worked.

 

[cjheven]

Wow, Just pulled the carbs off. The 2 small lines at the oil pump are blocked off as well as the larger line with the filter in it. The large line from the tank is still hooked up. There is a plate in place of the pump. Both cylinders as well as the carbs are slam full of oil. Bilge had alot of oil also. Sounds like it must be the the rotary valve shaft seal. Is it a huge deal to replace? Thanks so much for your response!

 

[cjheven]

Just looked up replacing the seal in the shop manual. Looks like major deal. Anyone on here had this done at the shop and know approx how many hours it takes? Thanks

 

[Minnetonka4me]

The rotory shaft seal is actually pretty easy with the carbs already off; you gotta pull the circlip holding the Shaft in, then use a puller to tug it out of the cases. then disassemble and reassemble.