Crankshaft questions

OldStrattonMan

New member
Ive read as much as i can on these different cranks and bearing sizes and need a little more insight. So i have a 130202 im building with some mild upgrades and didnt notice till the other day but my crankshaft was to short to accept a clutch, so i got on ebay and purchased a new crankshaft with the longer pto shaft, i also purchased the newer large bearing to go with it part number 555050 and ill be getting the side cover to match it. The crank and bearing came in today and i tried to fit the bearing on the shaft and its tight and will not fit. My question is are they designed this way to be tight if so i have a bearing heater at work to get the bearing on the shaft and does the bearing butt all the way up to the crank gear. Im still learning 20190617_184707.jpg more and more everyday on these engines and any help will be appreciated.
 

flattop1

Dawg 89
Short answer is yes .
The hot ticket is too slip fit the bearing .
In a racing application were quick easy replacment is needed.
 

OldStrattonMan

New member
Well i guess thats good news for me, im not sure if i want to attempt sanding down the journal to achieve a easier fit for the bearing. Unless theres easy ways to do it, now remember this is not for racing just some backyard fun with my son. I seen where a guy istalled the crank in a drill press with a single ball bearing to sand away the journal is this the normal way to do this mod
 
You can use a drill press but be sure to set the speed on the lowest setting. It will take very little to get the job done so check often until you get the slip fit. -- Chuck
 
Good advice, men.

Clearance the crank so that the bearing is a slip fit.
A lathe and crankshaft polisher is preferred, but a drill press and a little handywork will do.
Also, you may want to chamfer the inside radius on the bearing where it fits up against the radius on the crank so that it will fit flush agasint the side of the crank (and not just on that radius) - this will help in setting crank endplay during final assembly.


-----
?Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 

OldStrattonMan

New member
I want to thank everyone for the help, its so nice being in a group where people help and not bash you for asking question's. Brian im not sure what you mean by chamfer the inside of the bearing but is this necessary or can I get by not doing it, im going to plan on using the drill press method until the bearing fits on the shaft smooth.
 
I want to thank everyone for the help, its so nice being in a group where people help and not bash you for asking question's. Brian im not sure what you mean by chamfer the inside of the bearing but is this necessary or can I get by not doing it, im going to plan on using the drill press method until the bearing fits on the shaft smooth.
Chamfer on the inside race. You'll see it when you slip fit it the first time.
 
Top