This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

crank lateral runout

Joined Oct 2004
275 Posts | 3+
Reykjavik Iceland
I have just measured my crank up.
width over the crank pin = 59.96mm
width on the opposite of crank pin = 60.38mm
lateral runout on flywheel side bearing seat =0.20mm
lateral runout on clutch side bearing seat 0.16mm

this is a crank from a 04 FE650E with a 82mm stroke circular crank.
the 04 workshop manual states max width of the crank is 60 mm +- 0.05mm
and max lateral runout is 0.12mm.

so this is maybe why my clutchside mainbearing failed after 50 hours.
my question is how do i fix this? new crank pin? new crank?

regards
 
I had similar problem with my crank from a 04 fe450. width over the crank pin was 60.06mm and opposite was 60.20mm, not sure of the runout.
I took it to an engineer shop he got the widths down to 60.0mm at the pin and 60.05mm opposite and got the runout down to 0.06mm and 0.04mm (not sure on what sides)..
Not sure if itll last but theres only one way to find out..
 
The_Force said:
I have just measured my crank up.
width over the crank pin = 59.96mm
width on the opposite of crank pin = 60.38mm
lateral runout on flywheel side bearing seat =0.20mm
lateral runout on clutch side bearing seat 0.16mm

this is a crank from a 04 FE650E with a 82mm stroke circular crank.
the 04 workshop manual states max width of the crank is 60 mm +- 0.05mm
and max lateral runout is 0.12mm.

so this is maybe why my clutchside mainbearing failed after 50 hours.
my question is how do i fix this? new crank pin? new crank?

regards

Put the crank in a wise and press the down end until its less than 60mm, when pressure is on the crank, when engine is running, the crank flex a bit so it will extend above 60mm.
To be able to adjust the crank we always see that the crank halves is parallell before we straight the twist.
You will also see on your crank that its twisted, but you need a messuring device to do so.
50hrs on a crank is to little. you should get 100-150hrs if straight and welded.
Use the bearing set up described in the huge tread "main bearing failure" then you will be OK.
You can use a turnleath to see your crank twist, just see so the turnleath is straight as well before adjusting.

You do not need new crank or pin.

//Thomas
 
so press it together so its under 60mm and fix the twist.
how do i measure the twist?
do i just bang it around til the turnleath is whit in specs then weld?

im going to use the ktm 610 crate bearings
 
the two flywheel halves are identical so a simple ruler across the flywheel cheek ends will do. do it at 3 o clock and at 9 o clock. i have a twisted crank here and the two flywheel halves are 1.5mm out.

remember that this twist is on the big end pin ok? so you remember that one has swung around the pin.

regards

Taffy
 
Keep in mind you'll need 0,3-0,4 mm axial clearance for the rod to get the oil out.
 
the difference is now within 0.2mm on the width.
lateral runout on flywheel side bearing seat =0.03mm
lateral runout on clutch side bearing seat 0.05mm

is that good?
 
The_Force said:
the difference is now within 0.2mm on the width.
lateral runout on flywheel side bearing seat =0.03mm
lateral runout on clutch side bearing seat 0.05mm

is that good?

Its with in the limit.

dep on which way the width is big, below or above 60mm.
If above its easy to squize it a bit more in the wise.
If its below it will flex out when running and it will be ok.

/Thomas
 

Register CTA

Register on Husaberg Forum! This sidebar will go away, and you will see fewer ads.

Recent Discussions