I was curious if there was a part number for a crank seal that fits on another bike that would fit on a china girl. Kinda like how Dorman makes a Toyota O2 sensor exhaust gasket that fits on a china girl exhaust
CR or National seals each make every size seal possible, if you can find a online dimensions book you can find something much better than stock. You'll need a mic to get accurate measurements of the stock seals.
How you measure rectangles and squares by using Length x Width x Height
What order do you list the dimensions, in regards seals and things that are round? Such as thickness x diameter x inner diameter etc? I figured there is some formula so you get something with a 27mm inner diameter as opposed to something 27mm thick
The inner lip of the seal that rides on the shaft is 14.8mm. The seal bore is 27mm. The mag side is shallow so it uses the 4mm thickness. The gear side is deeper and uses the 7mm thickness. In general, the dimensions are listed in order of ID, OD, and depth (thickness). It also uses a TC shaft seal profile. There are many shaft seal profiles (cross section view). This is the TC profile (Shaft Oil Seal TC Rubber Covered Double Lip w/Garter Spring).
The 14.8mm ID is a bit odd, and I've been curious if a 15mm (more common) ID would work. The closest I've seen, that aren't made specifically for these engines, is TC15x27x5 and TC15x27x7 (millimeter).
At Smolik Performance website, the 70cc Minarelli Hybrid Engine comes with the option of: larger viton crank seals “…which will never fail.” The dimensions are not mentioned.