Main Journal specs?

[Motorrad]

Anyone have the specs for what the main journal should measure?   

Both where the main bearing sits and where the main seals ride.....

Mine is measuring between 1.181" and 1.1795"   depending on where I measure.

[kaw rider]

you know that journal has 2 steps to it. I would say .002" bigger then id of bearing.

[DoldGuy]

Motorad,
I was told by ......... Seal surface 1.179 Bearing surface 1.181
DoldGuy

[jonny500]

i was told only last week that 1 journal is slightly bigger than the other side. my response was, is that why 1 bearing seems to stay on the crank when spliting the cases. he said 'correct'. is this right anyone

[dave916]

Anyone have the specs for what the main journal should measure?   

Both where the main bearing sits and where the main seals ride.....

Mine is measuring between 1.181" and 1.1795"   depending on where I measure.

if the jounal is worn it will have a polished (chrome) look where the bearing spun,[common problem on kx]  worth double checking if the main bearing stayed in cases when taking motor apart ,
if you new bearing seem tigher on the crank than the old main bearing ,may be another sign {dont push the new one on to far
if the journal it tight you should see marks  running at 90degree to the crank web on the journal   
 i always check for any side movement on crank { big flat screwdriver between the crank and cases} when i have the topend off,as worn cases annd crank are common on kx
 

[Motorrad]

Motorad,
I was told by ......... Seal surface 1.179 Bearing surface 1.181
DoldGuy

I was too... But I am wondering now... as Both bearings stayed in the cases when pulled appart..... bearings were loctited onto the crank... and it came off easy... 

My new bearings.. I can snuggly put them on and off one journal by hand (aid of 2 shorty screwdrivers) on removal...   has me worried....   Im so used to my euro vintage stuff that is tight.. this doesnt seem right..

was hoping somone had a known good crank to measure for the good of us all.. as I cant find the spec in Clymer anywhere

[dave916]

if you can get the new bearing on by hand you crank is worn ,[ no need to measure it]
the bearing should be interference fit. that why you should have to use a pullers to split the cases
if the motor comes apart easily ,[ it usual mean something is worn [cases or crank journals]

even with a worn journal a new bearing can appear tight , [as  the crank is only worn slightly where the bearing spun,]
look for polished look on journal

if u rebuild engine with worn crank, may run ok for a few hours until crank starts moving sideway and damages the crankseals

[Motorrad]

if you can get the new bearing on by hand you crank is worn ,[ no need to measure it]
the bearing should be interference fit. that why you should have to use a pullers to split the cases
if the motor comes apart easily ,[ it usual mean something is worn [cases or crank journals]

even with a worn journal a new bearing can appear tight , [as  the crank is only worn slightly where the bearing spun,]
look for polished look on journal

if u rebuild engine with worn crank, may run ok for a few hours until crank starts moving sideway and damages the crankseals

Yes I realize all this... Not my first rodeo...  But I need a solid number for the journal sizes so I know how far off I am... so I can call the hard chrome platers and get her fixed.... seal serface and bearing serface

Reason I also am asking as my crank measures to exactly what stewart stated the measurements should be... to both me and DoldGuy...   

[kaw rider]

i have a crank here that measures 1.181 and seal surface 1.180.

[jonny500]

i have measured a crank and new bearing as photos show and have come up with an interferance fit of .0005 . from experience that is about right as a general bearing fit. my crank is good, no shine on the journal and i would not have a hope in hell of pushing it on without a press. please bare in mind this is a vernier and they are not the most acurate

[Motorrad]

You two are my hero's...

 

[Motorrad]

i was told only last week that 1 journal is slightly bigger than the other side. my response was, is that why 1 bearing seems to stay on the crank when spliting the cases. he said 'correct'. is this right anyone

I wonder on this also... as the two sides of my (not so hot in shape) crank. and my other junk one are differant from side to side..

On mine the flywheel side is smaller by .0003 or so...

[jonny500]

i have split 100s of engines and i never knew that cranks are different sizes on each end. that info came from a well respected motor engineer with alot of years under his belt, i have no reason to disbelieve. and it does make sense as when i split a case more often than not 1 bear stays on the crank. unfortunatly i dont have a good flywheel side to measure

[dave916]

00
i have split 100s of engines and i never knew that cranks are different sizes on each end. that info came from a well respected motor engineer with alot of years under his belt, i have no reason to disbelieve. and it does make sense as when i split a case more often than not 1 bear stays on the crank. unfortunatly i dont have a good flywheel side to measure

IN the cylmer it say (if the right main bearing came off with the crankshaft remove with bearing puller)page 197

i asume by this  there not expecting the left side (flywheel side) to be as tight
i too have a crank with the flywheel side worn,right side ok 
I personal would rather do both side to the tighter clearances [ maybe press the bearings on the crank,at least then i know  it would have little chance of wearing again

[jonny500]

dave916, it was chris applebee that told me this. i think if you do that it will cause some problems whemn the cases are put together and pulled apart, maybe