crank locking bolt and crank twist

bushmechanic · Feb 1, 2009

my 08 650 has its crank locking bolt on the rhs under the stator cover.

the 550 motor I have here has its crank locking bolt on the LHS of the crank as shown in the manuals.

in the manuals it says to tighten/loosen the flywheel nut with the crank locking bolt to stop the crank spinning.

I tried it in the 550 and it twists the crank. not enough to put it out of the 0.12mm limit in the manaul but enough to go from 0.04 to 0.10mm runout between centres.

its not a good idea IMHO. instead the flywheel should be locked with some kind of holder.

and on the bikes with a locking bolt on the RHS this bolt should not be used to hold the crank from spinning while tightening anything on the LHS.

the 550 had a failed main and its crank was badly twisted in the direction things go from tightening the flywheel nut as described in the manual.

sorry to state the bleeding obvious and apologies if someone has mentioned this allready.

regards
Bushie

Smorgasbord · Feb 1, 2009

Holding the flywheel does sound safe. Regards.

Taffy · Feb 2, 2009

in the manuals it says to tighten/loosen the flywheel nut with the crank locking bolt to stop the crank spinning.

didn't follow that?

regards

Taffy

AUSBERG · Feb 2, 2009

Some good points raised there.

Pity the 4T Kokusans werent like the 2T versions, that have 2 holes 180deg apart for a flywheel holding tool.

Even the old SEMs gave you a couple of indentations in the outer alloy hub to hold them with a special tool.

Another crankshaft "evil" which happens a lot is when people hammer away on flywheel pullers.....

I wont even get started on pneumatic impact tools, cause I got some people upset on another forum once when I aired my views :lol:

Taffy · Feb 2, 2009

Another crankshaft "evil" which happens a lot is when people hammer away on flywheel pullers.....

used to do that!

I wont even get started on pneumatic impact tools, cause I got some people upset on another forum once when I aired my views

i undo with them, is that ok?

regards

taffy

AUSBERG · Feb 2, 2009

Taffy said:
Another crankshaft "evil" which happens a lot is when people hammer away on flywheel pullers.....

Click to expand...

used to do that!
[quote:yyvfc670]
I wont even get started on pneumatic impact tools, cause I got some people upset on another forum once when I aired my views

i undo with them, is that ok?

regards

taffy[/quote:yyvfc670]

Undoing with them is definetly more acceptable ........

Its amazing how many people use them instead of a torque wrench and appropriate holder for reassembly though.

They've definetly got their place, and in the hands of a mechanically competent person their scope for damage is reduced substantially :wink:

.

spanner · Feb 2, 2009

Would you be able to undo the nuts with an impact tool without locking the crank, thus avoid the twisting as Bushy mentions?

ned37 · Feb 2, 2009

yes. when i use a 3/8 impact, i can just hold the flywheel with my hand

bushmechanic · Feb 2, 2009

hey spanner n ned that sounds good.

Taffy im sure you get it by now, twistimg the crank webs on the pin is the thing Im on about

ill be round for a tea later.

I 'm always surprised how easy it is to knock a crank out of alignment and Im flabbergasted they stay anywhere near true in the engine.

just putting one down on a bench a little rough with one web hitting the bench before the other is enough to send it out.

a lot of bike shops don't even check crank runout "we can't do anything about it anyway"

no wonder bikes with roller mains are hard to set up ........ 0.2mm runout .... blooday clowns !

BTW the 0.12mm runout spec in the manual comes from the old ball bearing mains days doesn't it ? seems like 0.05 should be a maximum, you can see 0.05 by eye.

reagrds
Bushie

spanner · Feb 2, 2009

Bushy all we need to do now is work out how to do it up again.
I remember hearing a story once when the first 1100cc Kawasakis came out they were having trouble with the cranks spinning so they increased the interference fit on the pins they needed 80 tons to press them, in sounds a bit much to me, but dose anyone know how many tons to press a Husaberg pin in or out?

bushmechanic · Feb 2, 2009

I didn't know I had a crank locking bolt so I made a tool to hold the flywheel

3" pipe ( i think) with 2 tangs to go in the holes in the flywheel.

then I found the locking bolt hidden on the flywheel side

some figures in this thread

http://www.husaberg.org/index.php?name= ... torder=asc

regards
Bushie

AUSBERG · Feb 2, 2009

spanner said:
Bushy all we need to do now is work out how to do it up again.
I remember hearing a story once when the first 1100cc Kawasakis came out they were having trouble with the cranks spinning so they increased the interference fit on the pins they needed 80 tons to press them, in sounds a bit much to me, but dose anyone know how many tons to press a Husaberg pin in or out?

Last time I pressed a 644 crank together was with a 50t Enerpac {which is a pretty good quality press} took less than 10t....(2nd hand pin).

It'll be getting tigged before it goes in the engine.

Enginehardware · Feb 3, 2009

Crank.

Hi.
I always use my impact gun to loose the bolts on the crank, and i have a 1/2" with torque regulator. I use it to tight the bolts as well.
I have during the past years done over 100 engines this way, with out problems, but one gets a feel for it.
If you do it first time, dont use a gun to tight, use a torque wrench.

Crank alighment: we always check the crank twist, its out of line by 70%.
Hit it straight and if you weld it and have a new conrod/bearing it will not be pressed apart for another 2-300hrs. Just change the mains by 100hrs.
Last crank we welded was 0.02mm out of line, we set a limit of 0.06mm then its to much.
It saves the mains when its as straight as possible.

//Thomas

Taffy · Feb 3, 2009

bushie

you really need to get out more.....

so basically, what you're saying is that if you were to work on the left of the crank then it needs locking on the left and vice versa? except that on the right i trust you can't reach this screw so you need a flywheel holder?

to do all that building and then re-measuring needs some kind of medal.

i am thinking of having a tool made that draws the crank through the left main. at the moment, well i can't put it any other way, i have to confess, tis true, yes honestly, i, i , i hit things, yes i know, i know, but tis true!

i can lever everything else but i can't lever the crank in.

regards

Taffy

Enginehardware · Feb 3, 2009

Tools for messure

Hi.
Just some photos what i use to check the twist. and a small device to hold the gears if nessesary.

If one is to do it correct, its easier with the right tools.

//Thomas

Taffy · Feb 3, 2009

RE: Tools for messure

thomas

how do you push the left side crank journal through the main? being aware that road bikes have a balancer assembly?

regards

Taffy

bushmechanic · Feb 3, 2009

RE: Tools for messure

bushie

you really need to get out more.....

so basically, what you're saying is that if you were to work on the left of the crank then it needs locking on the left and vice versa? except that on the right i trust you can't reach this screw so you need a flywheel holder?

yes i do, will be able to now the bikes a goer

so yes maybe TIG the pin and use a rattle gun for the flywheel or use a RHS locking bolt or make a holder.

the RHS on my bike can be locked easy without removing the flywheel. its the other bikes with the LHS locker that I would be concerned about. the thing to draw the crank through is a great idea,

FWIW the cranks Ive mucked with don't spread easily on the pin, just the twist is phenomenally easy to stuff up. what your doing is prolly ok especially since just about every used crank ive seen is spread ie bigger between lobes opposite the pin and what you do would close it up if anything (anti spread) maybe could stick a dial guage on the flywheel in the bike and measure the runout if your worried. or use thomas's idea with a turned nut.

nice photos thomas I made one of those stands. nice idea with the RHS nut .... I like your 0.06 limit, can someone change the dodgy manuals ? 0.12 between centres is for 2 big balls surely?

regards
Bushie

Enginehardware · Feb 3, 2009

Re: RE: Tools for messure

Taffy said:
thomas

how do you push the left side crank journal through the main? being aware that road bikes have a balancer assembly?

regards

Taffy

Ok.
We use the balancer also.

On the bearing type NJ( roller) its very easy due to the inner race is on the journal before installing. Heat it up the inner race and it slides on the journal easy or do as we do, just polish the journal to make it fit without pre heating.

The problem comes when you will use the KTM hardend ball bearing.
It dont come easy on the journal, and worse is when you want to take it apart due to the sprocket on the balancer drive is in the way, bearing cant pass.
The best way is to polish the journal so it slides easy into the bearing, that it can be removed with out any force.
If you dont want to reduce the journal diameter for the bearing to fit, then you have to use a press to slowly force the crank into the bearing, which is installed in the left case.
This is to see so the C/B fits correct with the sprocket(c/b drive).
Then hell comes when you should ones remove the crank.
The only way is then to press it out and on the same time knock the C/B drive shaft out, because the bearing will for sure not stay in the crankcase.

On our race engines with C/B we have made a small modification to make it easier, can send you the photo when its apart next time.

Life is not easy some times!!!

//Thomas

Krisbrumm · Feb 3, 2009

bushmechanic said:
I didn't know I had a crank locking bolt so I made a tool to hold the flywheel 3" pipe ( i think) with 2 tangs to go in the holes in the flywheel.

[/quote

I've got similar tool to hold the flywheel.Cause I'm lucky to upgrade my shop with precision lathe, I made such like ring which comes into the flywheel, around inside there are lots of "dowels".They lock my flywheel.I'm using them when tighten with torqe wrenh.To undo the nut, I use air gun and holding the flywheel with hand.It doesn't spin with that way.That sound quite safe,Itn't it?]

bushmechanic · Feb 3, 2009

this thing would look a bit funny if you hung it on thomas's wall

worked good once then I found the nice RHS locking bolt.

regards
Bushie

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