Bearing

[Rohnny]

I have my enginge in small pieces.  and I wonder if someone have thickness on the different bearing color on the connection rod and for the crank.

[Harvy]

I have my enginge in small pieces.  and I wonder if someone have thickness on the different bearing color on the connection rod and for the crank.

Found on a Kawa ZX14 forum:

"Yamaha used color codes for the rod bearing on my old FJ1200
in the Yamaha Service manual(chart) you looked up the color dot and wrote down what size bearings to order if you did not have a good O.D. micrometer. I think..................... it's been 20 years :-) "

That's all I can find at the moment.

Harvy

[Arnie]

According to the GYSM table on pg 3-34 -

Example 1: Selection of the crankshaft main bearings;
If the crankcase J1 and crankshaft J1 sizes are No. 4 and No. 1, respectively, the bearing size No. is:
Crankcase No. (minus) Crankshaft No. = Bearing Size No.  (4-1=3 which is brown)

Crank and Rod bearing determination is by same system and the codes are below

   Crank Code                                 Con Rod
Bearing Color Code:                   Bearing Color Code:
No. 1 = Blue                                 No. 0 = Pink
No. 2 = Black                                No. 1 = Blue   
No. 3 = Brown                               No. 2 = Black
No. 4 = Green                               No. 3 = Brown
No. 5 = Yellow

Seems a clunky system, but I guess that it would work as long as the journals haven't been damaged and/or reground.

Hope this helps,

Arnie

[racerrad8]

Exactly as both Harvy and Arnie have stated. They use a numbering system to determine bearing selection based on the bore/shaft size of the case/crank/rod.

The only thing that can be re-sized and reused is the rod. They should measure 1.1643 that is what I re-size to and it is a #4 rod size.

They use plasti-gage to determine if the bearings a beyond tolerance and warrant replacement.

Main Bearing Oil Clearance:
0.02 - 0.044mm (0.0008 - 0.0017")

Rod Bearing Oil Clearance:
0.017 - 0.04mm (0.0007 - 0.0016")

Randy - RPM

[Rohnny]

This is my numbering, but this looks like it inserted with a dremel.Is this correct that I may have different colors on same crank?

This is my old bearing.



All of my rods are marked with 4,


... and the manual says.

The connecting rods and caps are marked with a no 4 or 5. (fig 254) The crankshaft is marked on the left hand counterbalancer with a 4 right-hand set of number(b247) that relate to the connecting rod bearing journal.

That number is 22 21 22 11 2

Now I'm very confiused what kind of bearing I need to buy.


A picture of my old rod bearing. Why all the marks on the behind of the bearing. All of those looks like brown.



Would be better to know the size and meassure with a micrometer then.

[hpras]

Hi Rohnny.

I just went through this.  The numbers dremeled on the cases are for the main bearings.  Yes you can have different sized bearings on the same crank.  Yamaha never published what the journal sizes are, or what the bearing thicknesses are supposed to be.  The number on the crank refers to each journal on the crank, starting with the left main journal, htn ehte rod journal for cylinder one, then the next main journal, then so on.  Your rod journals are then sized 2121.  All of your roads are marked with a 4, so for cylinder 1 you need a 4-2=2 which is a black bearing.  For cylinder 2... 4-1=3 which is a brown bearing.  Same rules apply to the case. and main bearings.

[Rohnny]

What I do not understand is how you get 22 21 22 11 2 to be 2121.
So if I under stand the rod bearing correctly. The number on the rod is 4

rod printed      position       =      color
number
-----------------------------------------------
4             -        2             =  2  (black)
4             -        1             =  3  (brown)
4             -        2             =  2  (black)
4             -        1             =  3  (brown)


So to the crank.
The crank number looks like 5 4 5 4 6 (dremeled into crankcase) See 1st. picture
Number       Position      =     color
refferer   
5        -         1             = 4 (green)
4        -         2             = 2 (black)
5        -         3             = 2 (black)
4        -         4             = 0             ?
6        -         5             = 1 (blue)

[racerrad8]

So, by looking at the numbers you supplied (case numbers need to be verified, I read from left to right 6-4-5-4-5.

If they are and with the crank numbers you provided you will need;

Rods;

4) brown
4) black

Mains;

2) green
2) black
6) brown

When you order the bearings they only come in halves so you have to buy two for each journal. Also look at your old bearings, the paint code might still be present unless they have already been cleaned and wiped away.

Send me an email if I can be of assistance; rpm@swaybar.com

Randy - RPM

[racerrad8]

So to the crank.
The crank number looks like 64545 (changed left to right) See 1st. picture
Case   -       Crank            Bearing
6        -         2            = 4 (green)
4        -         2             = 2 (black)
5        -         2             = 3 (brown)
4        -         1             = 3 (brown)
5        -         2             = 3 (brown)

I made corrections above.

Randy - RPM

[Rohnny]

So the first I got right. Now I see the other part .
So to clearify for others.
crankcase num.     6          4           5            4          5
rod num                     4          4           4            4
cranknumber         2    2    2    1     2     2     1     1    2

so rod calculation      4-2 = 2
                              4-1 = 3
                              4-2 = 2
                              4-1 = 3

Crankcalculation
                              6-2 = 4
                              4-2 = 2
                              5-2 = 3
                              4-1 = 3
                              5-2 = 3

That give us as

says
If they are and with the crank numbers you provided you will need;

Rods;

4) brown
4) black

Mains;

2) green
2) black
6) brown

Crank and Rod bearing determination is by same system and the codes are below

  Crank Code                                 Con Rod
Bearing Color Code:                   Bearing Color Code:
No. 1 = Blue                                 No. 0 = Pink
No. 2 = Black                                No. 1 = Blue    
No. 3 = Brown                               No. 2 = Black
No. 4 = Green                               No. 3 = Brown
No. 5 = Yellow

Thanks alot.  This helps alot, and I will meassure the bearings with micrometer.  

[fj1250]

This is actually a very accurate system Yamaha uses for sizing the bearings. The difference between bearing sizes is something like .0002"  Yeah, it's very close.
The bearings are sized from tightest (thickest) to loosest. So the #1 crank bearing and the #0 rod bearing will have the smallest clearances. The #5 crank and #4 rod will have the largest clearance on the crankshaft.
Had a Yamaha rep tell me years ago you could use the brown bearings to build every engine adn probably be OK.
I built one engine with brown crank bearings and pink rod bearings. This was a Legends car engine that recieved thorough abuse and ran fabulous.
Best bet is to go with the numbers calculated from off the case, crank, and rods. You can't go wrong. Be sure to coat them with some kind of assembly lube and oil the rod bolts before torqueing the nuts.

Mike C 

[Rohnny]

  Today the bearing and piston rings arrived . That was relay fast delivery.
I took a micrometer and another meassure meter to test the sizes. But everyone got the same result 1.51mm 
Is'nt that strange. ? Do they only put color to confus us
Now I need to put the engine together. It's alot of screws 

[millosman]

So to the crank.
The crank number looks like 64545 (changed left to right) See 1st. picture
Case   -       Crank            Bearing
6        -         2            = 4 (green)
4        -         2             = 2 (black)
5        -         2             = 3 (brown)
4        -         1             = 3 (brown)
5        -         2             = 3 (brown)

I made corrections above.

Randy - RPM

Hi Randy

I've bought new crank and con-rod shells according to the description of how to determine correct sizes in my Haynes manual. (Model 3XW 1992)

It is different to the method described on here. Am worried that I may have got the wrong sizes now.

The Haynes manual states that the first 5 numbers on the crank relate to the five MAIN journals 1-5. The last four digits are the con-rod journals 1-4.

Can you confirm which method is correct please? See photo from manual.

My case no is 55555 and crank is 11111 1123 so I have based my con-rods on 1123 from the crank number and not 1112 using your method. Similarly I've used 11111 for the mains as against 11113.

Hope you can clarify. Thank you.
Yours
Confused
Andy

[racerrad8]

Andy, what bearings did you order for the case and rods?

I do not see a procedure in the photo you have provided.

Please confirm the numbers you are working with via photos of the numbers you have from the case, crank and rods.

From there, I will advise on the bearings required.

Randy - RPM

[millosman]

Hi Randy
I posted the pic to show the text that accompanies it saying to use the first 5 digits of the crank number for Mains and the last 4 digits are for the con-rods which is contrary to the other posts in this thread.

The same info is in both my Haynes and Clymer manuals. I'd love to see what the official Yamaha manual says but I haven't been able to find it anywhere in the Yam books I've got.

My data:-
Crank number 11111 1123
Con rods all stamped 4
Con rod shells I bought are 3321
IE 4-1, 4-1, 4-2, and 4-3
Brown brown black blue
So I have used the last four digits of the crank number.
What do you think Randy?