Squealing noise around stator and slow return to idles

G-Man · Post by **G-Man** » Mon Oct 26, 2015 1:37 am

Brickyard

That rod eye looks pretty horrible and has clearly been running hot with restricted oil supply. It would have been better to run a 15mm reamer through there but you are where you are. The heat has probably screwed up the thin hardened bearing surface and you will be looking at a limited life from that rod end.

I bushed the rods for my '61 CB72 but the crank has to come apart.

I'm not sure that I would reassemble the engine with what you have there but you might get lucky.

G

Brickyard · Post by **Brickyard** » Mon Oct 26, 2015 4:31 am

G, thanks for scaring me out of it. I all of a sudden dont want to half ass this part.

I now have 2 options:

1. wait for a connecting rod to show up for sale.
2. Ream. I'm trying to wrap my head around this process. Surely it requires an oversized wrist pin, right? If you were in my shoes, what would you tell a machine shop you need?

G-Man wrote:Brickyard

That rod eye looks pretty horrible and has clearly been running hot with restricted oil supply. It would have been better to run a 15mm reamer through there but you are where you are. The heat has probably screwed up the thin hardened bearing surface and you will be looking at a limited life from that rod end.

I bushed the rods for my '61 CB72 but the crank has to come apart.

I'm not sure that I would reassemble the engine with what you have there but you might get lucky.

G

Brickyard · Post by **Brickyard** » Mon Oct 26, 2015 4:39 am

There are several crankshafts that include connecting rods on ebay right now. Are there any differences between them other than bearings, or should they all be "plug and play?" Fortunately for me, a whole used crank shaft can be had for half the price of NOS connecting rods.

G-Man · Post by **G-Man** » Mon Oct 26, 2015 11:52 am

Brickyard

All this things are a gamble but a used crank is probably the cheapest option if it is in good order. At worst you'll have a pair of cranks to get a machine shop to build you one good one out of.

For a CB engine you need a right hand crank end with a lubrication hole for the starter sprocket. CL cranks do not have this.

You also need to know that the balance holes are bigger in a '77 crank (23mm) and a '72 crank (20mm).

PM me with some eBay links if you want an opinion..

OS pins are 15.1 mm so not a lot bigger than the regular ones. The last three didits of the part number will be "305".

G

Brickyard wrote:There are several crankshafts that include connecting rods on ebay right now. Are there any differences between them other than bearings, or should they all be "plug and play?" Fortunately for me, a whole used crank shaft can be had for half the price of NOS connecting rods.

Brickyard · Post by **Brickyard** » Mon Oct 26, 2015 4:26 pm

I went ahead and ordered a '65 cb77 crank on eBay for a good price i think, and it looks good.

Brickyard · Post by **Brickyard** » Thu Nov 05, 2015 1:58 pm

$85 plus shipping and 8 days later and I have a donor crank shaft. Its much better than I expected. Going to clean it, run G-mans oil drip test, and take my chances with the entire assembly vs breaking it down.

G-Man · Post by **G-Man** » Thu Nov 05, 2015 3:33 pm

Looks nice and clean....

I hope that one works out for you.

G

Brickyard wrote:$85 plus shipping and 8 days later and I have a donor crank shaft. Its much better than I expected. Going to clean it, run G-mans oil drip test, and take my chances with the entire assembly vs breaking it down.