Crank seals


New member
Hi everyone. Getting ready to put new seals in all my engines and wondering if I need the yellow seals from the kart shops or if seals from parts stores will work. Not trying to save $ just easier to get. But want the one that seals the best. Thanks in advance, Dave
The yellow seals imported by O&H have a carbon/tefolon lip. Those seals are now coming black in color, but are the same part.

For the Yamha, O&H is still importing the teflon only seal. This seal is black and has a green tinged ring on the outer face. Distinctly different seal so there is no problem visually identifying this teflon only seal compared to the carbon/teflon version.

In the Yamaha world I deal with, the Teflon seal outsells the carbon/teflon seal 5 to 1.

A good old Rolff double lip rubber seal will "seal" the best.

If you are building a 30HP engine that is hard to put 100% of the power to the ground, I would highly doubt that running a rubber seal would even be noticeable on the dyno, or the stopwatch.

I have almost every karting seal in Rolff DL or the newer CT the foreign engine world, most guys buy the CT seal. FWIW
If you are putting together something like a stock clone, then you might wish to use, if you can fine, the teflon.
For a HP type engine, any of the available seals will work well.
Bear in mind that a seal, like a bearing, rides on a very thin layer of oil. Once that layer is established, during warmup, the crank doesn't know or care what
is under the micro thin layer of oil, it is actually running on.
This is to a large degree also true of all mating surfaces in an engine.

"Grumpy" Jenkins had (he has passed away) had a good story on the oil film....which is where I recieved originally, this information.
It's a little bit long to put on this thread......or else I would post it.