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Author Topic: 85 250r crank shim  (Read 1073 times)

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85 250r crank shim
« on: July 02, 2013, 11:55:22 pm »
sorry if this question has been asked,  i am rebuilding my 250r new sleeve crank rebuilt with new rod.  New bearing throughout.  while assembling the crank the clearance between the crank and right side case bearing is .024 according to the factory manual the clearance should be .006-.008 which according to my math I need a crank shim .016-.018. the smalles shim i can find online is .024.  i double checked to make sure the bearings are fully seated and i used a crank puller to install the cranik in the left side case.  I do know the new bearing were a few thousandths (.003) thicker but cant see that making a big difference.  I mearsure the crank from web to web 55mm within specs.  Do I need to source a shim are not use a shim at all?
my first rebuild and I am leaning towards running without a shim HELP!
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Re: 85 250r crank shim
« Reply #1 on: July 03, 2013, 12:26:01 am »
Darn good question from a new member

Welcome to suzuki qrhq

I'm not able to answer your question but there will be a shift change and someone here will be able to answer   P*
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Re: 85 250r crank shim
« Reply #2 on: July 03, 2013, 05:17:09 am »
Are  you talking about side play on the crank. I think its not to be no more then 5 to .008. To check it you have to check bearing pockets for wear. If their good your bearings wont move and they should hold the crank in place. I had to have my pockets fixed, they were letting the crank move side to side around .024. or how much room was in their for the crank to go side to side.  You can also put the primary gear on and the flywheel and pull on the crank side to side to see how much side play in it.
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91 Lt250r Bartlett port and head mod v force 2 Hinson Clutch Basket Cool Head Scp Pipe and silencer ,KN air filter ,EBC clutch, Ohlins  Triple rate Shocks Redone by PEP Shocks,Stock Rear Shock Redone By Pep Shock,  DG nerf Bars , Lonestar axle 2+2,Lonestar Swingarm ,Douglas Red Label rims.

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Re: 85 250r crank shim
« Reply #3 on: July 03, 2013, 05:55:40 am »
Welcome,  I came across some left over shims from my bro's 86 when he had the crank rebuild 10+ years ago. I can measure them to check the thickness for you.
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Re: 85 250r crank shim
« Reply #4 on: July 03, 2013, 09:47:14 am »
Thank you all for the quick replies. 
Dezsled the bearing pockets are tight I warmed (approx 200 degress) the cases in an oven and froze the bearings before installing the bearings and had to gently tap them. 
With the crank pulled onto the left side case the crank does not move side to side. 
I am measuring the clearance between the right side of crank and the right side bearing.  According to the factory manual the smallest shim is too thick and doing a search on line I could not find anyone with a thinner shim.  I am guessing they do not exsist.
I found on Mcmaster carr shims that are .015thick but the OD is 2mm bigger.  Or do you think the extra clearance will be an issue or run it without any shims?

Gillo Thanks could you check your left over shims for me?

Thank you all again I think I am gonna like Suzuki QHQ D?
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Re: 85 250r crank shim
« Reply #5 on: July 03, 2013, 09:52:39 am »
Just thinking again about what you said Dezsled once the the clutch and flywheel are installed the crank cannot move so a little extra clearance should be no big deal. Right?  there is more than enough tolorence in the side to side crank to rod to compensate for the carnk off set an extra .016 correct?
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Re: 85 250r crank shim
« Reply #6 on: July 03, 2013, 12:59:17 pm »
 P*

Good stuff. You always need to start with a solid bottom end or everything else is pointless.
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Re: 85 250r crank shim
« Reply #7 on: July 03, 2013, 02:24:13 pm »
Sorry LT250rWV I should have/ meant to reference your reply
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Re: 85 250r crank shim
« Reply #8 on: July 03, 2013, 04:07:38 pm »
Some where I have a video of the side play in my crank on here il try to find it.It was bad.
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91 Lt250r Bartlett port and head mod v force 2 Hinson Clutch Basket Cool Head Scp Pipe and silencer ,KN air filter ,EBC clutch, Ohlins  Triple rate Shocks Redone by PEP Shocks,Stock Rear Shock Redone By Pep Shock,  DG nerf Bars , Lonestar axle 2+2,Lonestar Swingarm ,Douglas Red Label rims.

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Re: 85 250r crank shim
« Reply #9 on: July 04, 2013, 11:07:06 am »
Quote from: Bruce625 on July 02, 2013, 11:55:22 pm
sorry if this question has been asked,  i am rebuilding my 250r new sleeve crank rebuilt with new rod.  New bearing throughout.  while assembling the crank the clearance between the crank and right side case bearing is .024 according to the factory manual the clearance should be .006-.008 which according to my math I need a crank shim .016-.018. the smalles shim i can find online is .024.  i double checked to make sure the bearings are fully seated and i used a crank puller to install the cranik in the left side case.  I do know the new bearing were a few thousandths (.003) thicker but cant see that making a big difference.  I mearsure the crank from web to web 55mm within specs.  Do I need to source a shim are not use a shim at all?
my first rebuild and I am leaning towards running without a shim HELP!
[/quot
Quote from: Bruce625 on July 02, 2013, 11:55:22 pm
sorry if this question has been asked,  i am rebuilding my 250r new sleeve crank rebuilt with new rod.  New bearing throughout.  while assembling the crank the clearance between the crank and right side case bearing is .024 according to the factory manual the clearance should be .006-.008 which according to my math I need a crank shim .016-.018. the smalles shim i can find online is .024.  i double checked to make sure the bearings are fully seated and i used a crank puller to install the cranik in the left side case.  I do know the new bearing were a few thousandths (.003) thicker but cant see that making a big difference.  I mearsure the crank from web to web 55mm within specs.  Do I need to source a shim are not use a shim at all?
my first rebuild and I am leaning towards running without a shim HELP!


We usually adjust the end play when we press the crank together providing we have the cases with good bearing pockets and new main bearings installed.  We cannot accurately set the end play when someone just sends us a crankshaft to rebuild.

The space between the inner bearing races when the main bearings are installed and fully seated in the cases must be determined. 

The theoretical end play on the majority of the 250 two strokes is around .015".   This end play number is with the main bearings centered in their internal clearance.  Most new bearings that fit the 250 size cranks have about .006' total side clearance. 

Example:

Assuming .006" side drop in each main bearing:

 (The space where  the crankshaft lives) = (distance from the left case half to the inside bearing race + the distance from the right case half to the inside bearing race -.003" - .003) + the case gasket thickness if there is one

(The crank width) = the distance from the surface the main bearing shoulder up against on the left crank web to the surface the main bearing shoulder up against on the right crank web.


(The crankshaft end play) =  (The space where  the crankshaft lives) - (The crank width)
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Re: 85 250r crank shim
« Reply #10 on: July 05, 2013, 10:17:55 am »
Thanks MotorGeek!!
Funny I was thinking along those lines like maybe i could press the crank but that is a bit more than i can do at home, even though I have a press. Bumping a crank a few thousands could be difficult to control and what if i went too far.
Only wish the shop we sent the crank and sleeve to would have known what you told me. >:(
So at this point I am waiting for a shims from McMaster according to my calculations a .015 shim will get me at .009 clearance.  The factory service manual I have shows the clearance should be .006 to .008.  My only concern is the new shim will be 30mm id x 42mm od and the old shim is 30mm id x 40mm od. 
I am slightly concerned that the bigger od could interfere with the bearing lubrication. 
I am getting a pack of 10 shims so I have extras to play around with.
I feel pretty confident the lareger od will not cause a problem.
thanks for your input.
 Feeling better about this all the time!
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