How hard to reseal crank on 717

[Legacy37]

I removed my 717 That had leaking crank seals (earlier thread). I am thinking of keeping the core, resealing it and putting a new to end in it. It ran great before just leaked oil in the bilge. Is this feasible or courting disaster

 

[IDoSeaDoo]

if you mean the rotary shaft seal, not too bad. If you mean the inner crank seals, IMPOSSIBLE. It takes a special person with special tools and very special skills to rebuild a crank. It has to be pulled apart at the webs and pressed back togehter with new seals. IDK anyone that can do this. Only suggestion would be to go premix and run something thick in your rotary gear cavity, like LUCAS so it doesn't leak out.

 

[Legacy37]

I am not sure where it was leaking my crankcase was full of oil up to the carburetor

 

[mikidymac]

A leakdown test should always be done before and after an engine comes apart and goes back together.

 

[Mekanix]

Only 3 ways that can happen.
1 rotary seal is bad. Less likely
2 crank seals leaking on the inner lips.
3 crank seal outter lip to case is not sealing.

Id assemble dry and see where its leaking with a pressure test first.

First suspect us inner seal lips from experience but I have seen the outer lips be the culprit. And sometimes the case sealant was the cause when it got into the groove between the seal and case.