Topic: Honda CB400F crankshaft endplay

[everm1nd]

I noticed some knocking in bottom of engine and decided to disassemble it for revision. There is lengthwise crankshaft endplay about 1 or ever 2 millimeters. I don't find something about it in manual. In other (new) CB we don't find any endplay at all. Crankshaft fits perfectly. I don't understand where it comes from, because there is almost no any wearout. Seems like crankshaft endplay is a reason of knocking. Have you any ideas how I can fix it?

[camelman]

Please describe your question better. Is the endplay at the end of the connecting rod to the piston, or elsewhere?  There should be a little play at the connecting rod on the crankshaft. I don't know the exact amount, but maybe 0.5 mm play sliding forward and backward along the crankshaft. There should be no play when you push or pull on the connecting rod.

[everm1nd]

When I pull crankshaft from left to right holding at clutch there is some play. About 1 or 2 milimeters.

[LesterPiglet]

But your clutch isn't on the end of your crankshaft.

[camelman]

I think we need pictures to understand your question.

[everm1nd]

Oh, that's not clutch, year! Sorry, I don't know how it names in english.
I made a short video. There is no link coz i can't insert it. Just copy and paste it in your address line:
youtu.be/0Pv_uLES6DI

[LesterPiglet]

I'm no expert at this but have you tried putting the top crankcase on and see if it does the same?

[yesteryear]

Hi.
My 750 did that don't remember how much but when you re install the top case, cylinders,alternator and points seal mine did not do that any more.Done over 300 miles now no problems.Like I say mines OK don't know about yours.
Hope this helps

[everm1nd]

As I remember, there was some play with top cover, but may be it played less. I'm going to assemble it tomorrow, hoping that play will go away.

[yesteryear]

Forgot to mention I did fit new Honda main bearing shells.
Regards

[everm1nd]

Thanks for advice, but I'm going to change bearings this winter. I also have some troubles in cylinders head, so this will be big job.