MAIN BEARING QUESTION

[itsacbx]

hey y'all,
Im helping a friend rebuild his 80 engine and he raised a question I thought I throw out for commentary....
4 of the main bearings have noticeable marks on them which suggests it not wise to just reassemble the engine with the existing bearings. When I last checked he hadnt dismantled the rods but I suspect there will be similar degradation. Mileage is about 50,000 [miles not km].
His question is - if he buys the identical bearing as fitted when new is that a satisfactory answer to improve clearances and prolong the life of the engine? This will be one of many bikes he owns and it likely wont see more than a few hundred miles each year of gentle wandering around the 'burbs. His oil of choice is Shell or Casterol 20-50 mineral oil, changed every 1500miles or 2 years, whichever comes first.
Al

[Jeff Bennetts]

Get the Brown shells for the crank Al, like most things Honda was anal when it came down to clearances, also remember they were working with Dino oil, not the blends we have now.

[itsacbx]

thanks Jeff, ill pass it on to him....
Enjoy Daytona!
Al

[daves79x]

What am I missing here? When replacing bearings, you can often see the color still present on the shell. Whether you can see the color or not, you verify by cross-referencing the crank journal code and the crankcase code what size, or color of bearing you need. That's the size bearing you should get. Yes, it is true that there are very small differences in bearing size, but why mess with what works?

Dave

[daves79x]

I forgot to add that you must Plastigauge every bearing before final assembly to be sure you've got it right and/or there is no previously undetected wear in a journal.

Dave

[itsacbx]

the colours on the originals were still visible, so he has purchased all new ones in the same colours. We will plastigauge them as well before final assembly.

[daves79x]

As I said, the FSM cross-reference chart should be double-checked so you know if something odd has been used.

Dave