Crank Binding issues

Anything related to Lambrettas... ask tech questions, post helpful info, or just read and learn.
yellow peril
registered user
Posts: 33
Joined: Sun Nov 22, 2009 3:59 pm
Contact:

I am just in the process of fitting a new JB corsa crank (60x107) however when fitted in the drive side it catches very slightly at the bottom of the stroke, the crank and bearing are fully 'home' however when fitted the mag housing it actually locks at the bottom.
I have checked the crank and the rod is slightly proud of the webs by 15 thou, is this normal? as my std crank is below the webs.
I am a bit stuck as dont want to be getting the dremmel on the casing.
Any ideas welcome
DJB
Dealer
Posts: 186
Joined: Sun Nov 15, 2009 6:35 pm
Location: Colchester
Contact:

Did you change the drive side bearing, if so, check the plate is flat. If its an alloy one, replace it with a steel one. This sounds like the problem. If not, check the pin is not proud of the webs. If this dont work, go back to JB.
yellow peril
registered user
Posts: 33
Joined: Sun Nov 22, 2009 3:59 pm
Contact:

Yes new drive bearing and MBD steel plate, will re check the seating
DJB
Dealer
Posts: 186
Joined: Sun Nov 15, 2009 6:35 pm
Location: Colchester
Contact:

Use a black marker pen on the plate before you put the crank back, this should show you where its rubbing.
yellow peril
registered user
Posts: 33
Joined: Sun Nov 22, 2009 3:59 pm
Contact:

DJB wrote:Use a black marker pen on the plate before you put the crank back, this should show you where its rubbing.
All sorted cheers, it was rubbing on the casing near the mouth where it chamfers etc... a quick 'tickle' with the dremmel and all's well
Cheers
shocky
registered user
Posts: 2139
Joined: Wed Jan 07, 2009 12:33 pm
Location: cheltenham
Contact:

yellow peril wrote:I am just in the process of fitting a new JB corsa crank (60x107) however when fitted in the drive side it catches very slightly at the bottom of the stroke, the crank and bearing are fully 'home' however when fitted the mag housing it actually locks at the bottom.
I have checked the crank and the rod is slightly proud of the webs by 15 thou, is this normal? as my std crank is below the webs.
I am a bit stuck as dont want to be getting the dremmel on the casing.
Any ideas welcome
are you saying the big end eye is sticking out past the circle of the crank webs when the rod is at bottom dead center i have seen this befor but on a rotax rodded engine the answere was to dremmel a grove in the back of the case so it didnt touch
We sleep soundly in our beds because rough men stand ready in the night to visit violence on those who would do us harm
Post Reply Previous topicNext topic
  • Information
  • Who is online

    Users browsing this forum: Google [Bot] and 1 guest