ETZ 250 Bearing sizes for engine

[Cerberus73]

Right i need a comprehensive answer if possible.. i plan on doing for my MZ what i did when i rebuilt the engine of my Honda C90 stepthrough. and that is replace every bearing with a known quality make like Koyo or SKF.. so i don't want a ready put together kit of bearings and gaskets like you can find on Ost2Rad or other MZ parts suppliers, as i don't know the brands they are offering. and i know from experience of doing the honda ones that the OEM was koyo but cost 2-3 times the price i was from a bearing supplier for exactly the same part. this information will be useful as well to place into a archive for other members to use as reference. so if any of the UK or European members who have rebuilt or pulled apart the 250/251 ETZ engine know the answer for all the gear box, main crank and big and small end bearing sizes and specs id be very grateful.

Same with crank seals i want to be sure that the rubber will be ethanol proof as i know from experience of other bikes it can be problematic

[Cerberus73]

ok i went and done a little research.. digging around in some old MZ part catalogues, manuals etc i got with my bike as pdf's and printed. and I've compiled a list of bearings from them. so for anyone interested.. here is a comprehensive list. remember this is for the earlier 250 not the 251 or 301.. the engine is different on that model. so some research on your own may be required.

MZ ETZ 250 Bearing List (Note I start with outer diameter, inner, then width)

ETZ 250 Engine Bearings


Bearing 6203 C3 40mm x 17mm x 12mm (Require 2)

Bearing 6304 C3 52mm x 20mm x 15mm

Bearing 6204 C3 47mm x 20mm x 14mm

Bearing 6306 C3 72mm x 30mm x 19mm (Main Crank Bearings Require 2)

Bearing 6302 ZZ Type C3 42mm x 15mm x 13mm (Metal Shielded Type)

Bearing 16005 C3 47mm x 25mm x 8mm (Clutch)

Bearing Caged Needle Roller Double Row KK Type 18mm x 22mm x 24mm (Small End Bearing)

Bearing Caged Needle Roller Double Row KK Type 32mm x 40mm x 22mm (Big End Bearing)

Bearing Caged Needle Roller Double Row KK Type 22mm x 26mm x 26mm (Clutch)

(note single and double row bearing seem to be used and available for this model.. it seems maybe MZ used whatever was available to them during production. so feel free to use K type single row or KK type double row type)

Wheel Bearings

Bearing 6302 ZZ Type C3 42mm x 15mm x 13mm (Metal Shielded Type) Require 4

Headstock Bearings

Bearing 6006 C3 55mm x 30mm x 13mm Require 2

Rear Drive Bearings

Bearing 6005 ZZ Type C3 47mm x 25mm x 12mm (Metal Shielded Type)

Bearing 6204 C3 47mm x 20mm x 14mm

[Guesi]

Hello

some bearings are not right:

MZ ETZ 250 Bearing List (Note I start with outer diameter, inner, then width)

ETZ 250 Engine Bearings


Bearing 6203 C3 40mm x 17mm x 12mm (Require 2) 6203 J C4

Bearing 6304 C3 52mm x 20mm x 15mm 6304 J C4

Bearing 6204 C3 47mm x 20mm x 14mm 6204 J C4

Bearing 6306 C3 72mm x 30mm x 19mm (Main Crank Bearings Require 2) 6306TNG C4

Bearing 6302 ZZ Type C3 42mm x 15mm x 13mm (Metal Shielded Type) 6302 TN C3 (without ZZ.It makes no sense using shielded bearing in an engine)

Bearing 16005 C3 47mm x 25mm x 8mm (Clutch)

Bearing Caged Needle Roller Double Row KK Type 18mm x 22mm x 24mm (Small End Bearing)

Bearing Caged Needle Roller Double Row KK Type 32mm x 40mm x 22mm (Big End Bearing)

Bearing Caged Needle Roller Double Row KK Type 22mm x 26mm x 26mm (Clutch)

(note single and double row bearing seem to be used and available for this model.. it seems maybe MZ used whatever was available to them during production. so feel free to use K type single row or KK type double row type)

Wheel Bearings

Bearing 6302 ZZ Type C3 42mm x 15mm x 13mm (Metal Shielded Type) Require 4

Headstock Bearings

Bearing 6006 C3 55mm x 30mm x 13mm Require 2

Rear Drive Bearings

Bearing 6005 ZZ Type C3 47mm x 25mm x 12mm (Metal Shielded Type)

Bearing 6204 C3 47mm x 20mm x 14mm no C3, only 6204 without "C3"

And by the way:
I sell a set of bearings SKF made ....