rotax 717 hydrolocking with oil

onion79

Recruit
Joined
May 16, 2015
Messages
3
Hi. Purchased a 97 sportster with a rotax 717.
Took it out for first time yesterday. Started good. It seemed a little sluggish and seemed to smoke excessivley imho but im not sure.
I decided to check compression. I left 1 plug in and put the tester in the other plug hole. Engine would not turn at all.
Took tester and other plug out. Engine turned and shot oil EVERYWHERE.
Put plugs back in and again it would not crank.
The cylinders are full of oil for some reason.
I there was about a gallon of oil in the tank yesterday. I took the boat out for 20 minutes. Today there is barely any oil in the tank. I cant believe it couldve used that much oil in such a short time.
What is going on here?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Hi. Purchased a 97 sportster with a rotax 717.
Took it out for first time yesterday. Started good. It seemed a little sluggish and seemed to smoke excessivley imho but im not sure.
I decided to check compression. I left 1 plug in and put the tester in the other plug hole. Engine would not turn at all.
Took tester and other plug out. Engine turned and shot oil EVERYWHERE.
Put plugs back in and again it would not crank.
The cylinders are full of oil for some reason.
I there was about a gallon of oil in the tank yesterday. I took the boat out for 20 minutes. Today there is barely any oil in the tank. I cant believe it couldve used that much oil in such a short time.
What is going on here?

The oil injection system is belly up. Many remove the system and just mix the gas and oil in the fuel tank. Then you no long have to bother with it and it will never damage the engine due to lack of oil.

Here is a thread on how to bypass the system
http://www.seadooforum.com/showthread.php?45851-Bypass-oil-injection-HOWTO
 

onion79

Recruit
Joined
May 16, 2015
Messages
3
I did some research and what others have posted is that crank and/or rotary valve seal is shot.
I would be happy to bypass the pump but this much oil cant just be coming from where its injected into the engine, or am i wrong? If its coming from the rotary valve and i connected the 2 hoses wouldnt it just run it dry?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
I did some research and what others have posted is that crank and/or rotary valve seal is shot.
I would be happy to bypass the pump but this much oil cant just be coming from where its injected into the engine, or am i wrong? If its coming from the rotary valve and i connected the 2 hoses wouldnt it just run it dry?

Not an expert but I'll agree with you, looks like the crank seal. In the link below the guy in post 11 has a method to prolong it before it has to be replaced. That is so long as it is not to bad
http://www.pwctoday.com/showthread.php?t=332649&page=2
 

Brian 26

Chief Petty Officer
Joined
Aug 14, 2013
Messages
574
Sounds to me like you're rotary valve is the issue. If that is the case changing over to premix and bypassing the oil injection will not help as the rotary valve still needs an oil bath (step 5 in the linked premix instructions).
 
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