Crank bearings good or bad

[Acro1985]

Please can I have some help understanding the clearances.

Just plastigauge my crank with the existing shells in and the reading is 0.050mm or 0.002 inches across them all but I have no idea how I use this information in helping select the right shells. The service manual says if they are in excess of 0.08mm or 0.0031 in they should be replaced which I am assuming mine are within the tolerance

[Bryanj]

They are fine for tollerances, you just need to sort out what size the damaged ones were

[McCabe-Thiele (Ted)]

Your photo is showing the inches scale rather than the mm one - putting that aside the amount of "squash" (Derbyshire techical speak) on the Plasigauge looks pretty good to me.

[taysidedragon]

The clearances are within spec, but the crank journal looks ridged and marked. I would take the crank to an engineering firm for their opinion.  Probably needs a regrind.

[McCabe-Thiele (Ted)]

The clearances are within spec, but the crank journal looks ridged and marked. I would take the crank to an engineering firm for their opinion.  Probably needs a regrind.

Didn't think you could regrind these old Honda cranks?

My 500 crank was badly ridged found a decent replacement from DK.

[Acro1985]

The clearances are within spec, but the crank journal looks ridged and marked. I would take the crank to an engineering firm for their opinion.  Probably needs a regrind.

You can't feel any of them with your finger nail so they don't appear to be deep

[McCabe-Thiele (Ted)]

It might just be burnt oil (carbon) deposit on the journal - try cleaning it off with some Brasso cloth. I had it on my 400 big ends and on the conrod where the shells sit.

[Bryanj]

No you cant regring Honda cranks, well technically you can but undersize shells dont exist!

[Murf]

That’s strange on the first photo of the crank the journals looked very nice, now on the photos with the plastigauge they look really scoured, is it due to some strange light effects on the photo.
That apart it looks like the bearings are in spec.

[Acro1985]

I think it's the camera on my phone and probably the grease I put on to hold the plastigauge in place. As when I cleaned it up afterwards the journals look really good

[McCabe-Thiele (Ted)]

As far as I'm aware you don't grease or oil the bearing when using Plastigauge - at least I never have.
It might even give you a false clearance value.

[Acro1985]

The instructions with the plastigauge said to use a little bit of grease to hold the plastigauge in place

[McCabe-Thiele (Ted)]

I had no instructions so I did it dry.

[Acro1985]

Just checked one the big end bearings with the plastigauge and not sure it's squished right or is it just how it's separated when taking the end cap off

[taysidedragon]

It does that sometimes.  The outer measurement is unaffected.