1979 triple main bearing issue

T

treoleileagh

Full member
Location
Australia
Short of waiting for metallic clanging and shrapnel, is there an easy way to know if a motor has had the defective bearing fixed (maybe a recall stamping on the case or something)?
 
Things were not that organised back then as far as I know, though it would have made a lot of sense.  Unless it's very very low mileage you'd think it would have blown up by now.  I just got a crank refurbished which was in perfect nick still with the ball bearing centres, but the engine was out of a bike written off early in it's life and had been in storage since.

You *might* be able to get a partial view of a bearing with a bore scope in through the oil filter or camchain hole.  Worth a try?
 
if the bore scope idea does not work.....

engine out is fairly quick, drain the oil, flip the engine over, and just pull the bottom engine case half, leaving the head/barrels/cam chain/crank etc. all intact. Not particularly easy but pretty quick as compared to a total engine strip.

any idea on the kms on this motor? What is the engine serial number? See below for affected engine serial numbers:

from Laverda Mania

* Note concerning the wrong bearing batches in 1979:

In 1979, like described in the "1000" chapter of this site, some bikes had been equipped with a wrong batch of bearings, meaning failures and broken engines.
Here are the serial number of these bikes:

1000:
- From the serial number 6204 to 6594
- From the serial number 6598 to 6603
1200:
- From the serial number 1519 to 1566
- From the serial number 1833 to 2533

http://www.laverdamania.net/roulementgb.htm
 
Thanks Breganze, Paul,

I'll get a bore scope and see what I can do with it first. The motor now starts and seems fine and my concern is really just cautionary. The bike is from the affected series though and the guages are new so the milage is unknown. On another question, matter can you tell me the reading I should expect to see on a compression guage for a Jota?
Thanks again,
Chris
 
depending on the condition of the engine, 145-155 psi with wide open throttle
anything above those figures is a bonus


 
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