GB 113A Flywheel seal will provide better sealing than any other seal(s) offered including the inferior double seal offered by many. I, personally, have never had a premature flywheel seal leak problem with any engine I have built using one of these seals. If this seal leaks, nothing will stop the problem as it is caused by:
1. Case being line bored out of line with the seal hole.
2. Crankshaft bent or out of line from end to end. Many grinders do not get the alignment correct and grind the crankshaft off its own center line.
3. Worn out flywheel lip.
4. Not properly installed in the case and/or properly pre-lubed.Note: Be sure to lube the inside of any seal when installing it, otherwise it will burn when the engine is first cranked over (even by hand), causing small heat cracks in the seal lip. This usually is the cause of most premature flywheel seal leaks. Never put any sealer on the ID or OD of the seal or any oil on the OD when installing it.