Glue the main bearings?

[Polar-Bus]

slip fit hmm i would like to know the result of this experiment. unfortunatly my 500 motor is built now so i cant try it in mine, what a shame i found some pics dont mean to worry any one

That motor didnt fail due to a slip fit bearing....     Or any kind of main bearing issue   from what I see in those pictures...     


My Personal vote.... Cast piston strikes again

In my 25+ years of using cast OEM piston's i've never seen one fail for no reason.  I have seen many cast pistons (and forged) fail due to excessive wear and "skirt slap" against the cyl walls.... I personally have much respect for the consistant relibility of OEM cast pistons.  One things clear in the pic is that that engine failure was a WFO,  catastrophic piston granade to do that much extreme damage.. (strictly just my opinions)

[tschisi]

if you crank is worn on the journal you have a problem
It was worn, that?s why i sent it to the "machine shop"

why did they not fix it

Well, they did something.

I had a worn journal of the left main bearing.
It could be felt with the fingernail.


Now the area is shiny, maybe just polished or so.
The notch is still there, but the bearing also slides over the seal-area which wasn?t damaged?!


The bad thing is that i just didn?t have a close look at the journal after the "repair", was blinded by the shiny surface.
Removing it again will damage the right bearing...

Motorrad,
How much play did your bearing have?
Was it a k5 (so you had to glue the bearing and insert crank into seal at the same time)?

[kwakman]

tschisi, how did you resolve your seal seat damage?

[tschisi]

No fixing needing.
As the seat itself is undamaged, and only about 1/5 of the stop is broken out, this doesn't effect the sealing function.
Confirmed by a kawi-mechanic.
The stop just prevents the seal from getting pushed out...

[kwakman]

your lucky.dont forget to use case sealer round the out side of seal.K.

[Motorrad]

if you crank is worn on the journal you have a problem
It was worn, that?s why i sent it to the "machine shop"

why did they not fix it

Well, they did something.

I had a worn journal of the left main bearing.
It could be felt with the fingernail.


Now the area is shiny, maybe just polished or so.
The notch is still there, but the bearing also slides over the seal-area which wasn?t damaged?!


The bad thing is that i just didn?t have a close look at the journal after the "repair", was blinded by the shiny surface.
Removing it again will damage the right bearing...

Motorrad,
How much play did your bearing have?
Was it a k5 (so you had to glue the bearing and insert crank into seal at the same time)?

Yes mine is slip fit on the Ignition side.

The Seal surface is supposed to be smaller than the bearing surface.

when putting together use the Freeze Heat method I have described In Chris 's KX60 section..     and elseware...

To use the loctite properly, you put a bead of it around the crank, on the leading face of the bearing surface.... and drop the case on... whala...


Just remember, if you ever want to take it appart again... that loctite I listed is EVIL STUFF..       you WILL BREAK THINGS, trying to get her back appart unless you use a torch to release the loctite.

[tschisi]

Use the heat/freeze method although the parts could be put together at the same temp (because of the slip fit) ?

[kwakman]

if your right side is done, use heat freeze to get the left bearing in case, if you have the clearance your left should slide into crank without, depending on your clearance.K.

[dave916]

Use the heat/freeze method although the parts could be put together at the same temp (because of the slip fit) ?

that crank needs repairing{ probably both sides} your bearing journal diamater is smaller than seal surface,
 you may be lucky with the  lockite but i would not take a chance
I personally think the kx500 is the one motor that u have to have the journals as tight as possible 

As i said on my lasts post, on a cr500 and other hondas the bearing is locked to the journal with the primary gear bolt, no chance of the crank moving sideways on the journals
A honda mechanic might not be the best person to get advice from

before i strip a motor i always check the crank for side movement, about 50% of kx5 motor i have either have the journal or cases worn

[jonny500]

Use the heat/freeze method although the parts could be put together at the same temp (because of the slip fit) ?

that crank needs repairing{ probably both sides} your bearing journal diamater is smaller than seal surface,
 you may be lucky with the  lockite but i would not take a chance
I personally think the kx500 is the one motor that u have to have the journals as tight as possible 

As i said on my lasts post, on a cr500 and other hondas the bearing is locked to the journal with the primary gear bolt, no chance of the crank moving sideways on the journals
A honda mechanic might not be the best person to get advice from



before i strip a motor i always check the crank for side movement, about 50% of kx5 motor i have either have the journal or cases worn

+1 dave is right imo

[tschisi]

Oh man, more and more costs.
Anyone wanna buy k5 parts? 

[RoostiusMaximus]

that picture of the broken cases clearly shows the rod broke, not the piston.
I'd build up the crank or get another.

[jonny500]

Oh man, more and more costs.
Anyone wanna buy k5 parts? 

dont quit yet, you have hardly got started 

[kwakman]

a couple hundred dollars now may save having to start again 6 mths down the line.Your call.K.