Ducati Monster Forum

Moto Board => Tech => Topic started by: He Man on May 22, 2011, 08:33:59 PM

Title: Spun Rod Bearing
Post by: He Man on May 22, 2011, 08:33:59 PM
If you spin a rod bearing, does it always damage the crank? If yes, can it be repaired without using thicker rod bearings?

:P no its not the monster.
Title: Re: Spun Rod Bearing
Post by: Mother on May 22, 2011, 08:39:40 PM
my experience in this come from 350's and 258's

the answer is yes and no

if you spin a rod bearing it will always damage something

but

from what I have seen

it typically always damages the cap worse than the crank if caught very very early

it doesn't necessarily mean you have to turn the crank

but its a very good idea if you don't want to have it happen again





Title: Re: Spun Rod Bearing
Post by: He Man on May 22, 2011, 08:49:12 PM
if you turn the crank then you need larger bearings to make up for the gap?
Title: Re: Spun Rod Bearing
Post by: Mother on May 22, 2011, 08:56:25 PM
Quote from: He Man on May 22, 2011, 08:49:12 PM
if you turn the crank then you need larger bearings to make up for the gap?

yep

thicker bearings

Title: Re: Spun Rod Bearing
Post by: Mother on May 22, 2011, 09:02:01 PM
also

ive read that newer motors are coated in a similar fashion as forks

and

turning the crank isn't recomended
Title: Re: Spun Rod Bearing
Post by: He Man on May 22, 2011, 09:07:02 PM
:(  im pretty sure the crank is cooked. will get a plastiguage and check against  the spec.

thanks man!
Title: Re: Spun Rod Bearing
Post by: Mother on May 22, 2011, 09:15:55 PM
Quote from: He Man on May 22, 2011, 09:07:02 PM
:(  im pretty sure the crank is cooked. will get a plastiguage and check against  the spec.

thanks man!

check in with speeddog, stu, and the tech guru's

they will have a much more solid knowledge base

Title: Re: Spun Rod Bearing
Post by: Langanobob on May 24, 2011, 05:14:26 PM
Quote from: He Man on May 22, 2011, 08:33:59 PM
If you spin a rod bearing, does it always damage the crank? If yes, can it be repaired without using thicker rod bearings?

:P no its not the monster.

He Man, it's been awhile but you used to be able to get crank journals welded up and machined back to factory dimensions and I think you still can.  The shop has to be good.  But, for the same or less money you could probably buy a good used crank or two.  Or three?

Every time I try to take a shortcut I end up with an Epic Fail.  But I know a guy who sanded down his damaged crank with emery cloth, put in undersize (thicker) bearings and ran it for a long time.  Not a Ducati.

Bob



Bob