Eric, crankshaft bearings C3 or C4 ???

[mxelbio]

Hi Eric
Idont find it this topic in your book, so my question , are the same bearings with denomination C3 or C4 for my Crankshaft Cr 125 '00...
My mechanic told me that C4 have more free play or clearence that C3 and C4 are more safety because heat in the crankase room......
What hapend if i put 6322 C3 on my motor, can hapend some type of damage on high RPM..!!!!!!
Thanks, and congratulations for the book.!!!!!

 

[marcusgunby]

Im not sure whats std but stick with what honda uses-ive known people try tighter fit bearings, and get very short life from them.

 

[vmxservice]

The Maico's I ride all have c3 bearings for the crankshaft. But if iI recall correct my Husaberg('02) has c4 mounted.
c3 and c4 bearings can handle the heat and stress from the changing RPM better.

 

[mxelbio]

on my Honda CR 125 '00 STD bearings are NTN 6322 C4 .

 

[Esp1]

From my experience it does not matter much if you choose to use the C3 or C4 bearings in your 125cc engine, if you use it for MX. Some manufacturers use the C3 and some C4. But, when the engines are modified for higher rpm’s than they are designed for it seems like the C4’s are the best choice.
Something to be aware of is that the clearances in the C3 and C4 bearings DOES overlap each other. So in the worst scenario, if you get a C4 with the tightest production clearances and a C3 with the roomiest production clearances, the C4 will have a tighter clearance than the C3!
Anyway, as you may figure they are pretty close to each other!

Hope you got my point. I sometimes find it hard to explain technical stuff in a simple way, since my English is not that good.

Good luck!

 

[mxelbio]

english is not my mother language too, spanish is..!!!!!!! i understand your point and i think the same......and is more important to use a high quality brand of bearings like Germanys FAG or Swedish, or why not Bearings from Norway..!!!!!!!!
So which brand is the best in your opinion ?
Thanks for answer me, i´m on south antartic, and you on north Artic, ....internet is amaizing..!!!!!
Regards.

 

[Esp1]

Yes, internet is truly amazing, both in good and bad......
Definitley a great "tool" to have :thumb:

I've had good experience with both FAG and Koyo in crankshaft applications.
Actually seen quite a few SKF C3 bearings come apart, not good...... :eek:

 

[Zenith]

C4 is the standard bearing for the 00 CR125 but because they are so hard to come across unless you get them from Honda all the mechanics here put in C3 bearings....
I'm about to put C3s into my 00 CR so I'll let you know if the engine falls apart :confused:! (I don't expect it to, I've used C3s before with no problems)


Philip