Buying one case half?

CLT809
Posts
186
Joined
9/2/2013
Location
Little Elm, TX US
Fantasy
16th
Edited Date/Time 4/23/2022 1:42pm
So I received a YZ125 that somehow has a chunk of the left crankcase half missing at the rear where the swingarm pivot goes through. This may be a stupid question, but I just wanted to see if anyone has ever had an issue replacing only one case half? (ie: issues with bearing bores not lining up perfectly from batch to batch)


|
lwtracer
Posts
110
Joined
2/1/2022
Location
Lancaster, PA US
Fantasy
391st
4/21/2022 5:57pm Edited Date/Time 4/21/2022 5:57pm
nearly all case sides are matched together from the factory.

If the holes on each side are not line up perfectly you will destroy crank/crank bearings/transmission bearings and the cases again.

if you have the missing piece, just get it welded.
1
4
Brad460
Posts
3679
Joined
5/15/2012
Location
Richfield, WI US
Fantasy
736th
4/21/2022 6:05pm Edited Date/Time 4/21/2022 6:05pm
lwtracer wrote:
nearly all case sides are matched together from the factory. If the holes on each side are not line up perfectly you will destroy crank/crank bearings/transmission...
nearly all case sides are matched together from the factory.

If the holes on each side are not line up perfectly you will destroy crank/crank bearings/transmission bearings and the cases again.

if you have the missing piece, just get it welded.
If cases are matched they wouldn’t sell them as separate part numbers..

Yamaha sells case halves so he will be fine.

Plus I can assure you, if you buy both halves they are not coming “matched”, your getting two random parts.
33
CLT809
Posts
186
Joined
9/2/2013
Location
Little Elm, TX US
Fantasy
16th
4/21/2022 6:08pm
Brad460 wrote:
If cases are matched they wouldn’t sell them as separate part numbers.. Yamaha sells case halves so he will be fine. Plus I can assure you...
If cases are matched they wouldn’t sell them as separate part numbers..

Yamaha sells case halves so he will be fine.

Plus I can assure you, if you buy both halves they are not coming “matched”, your getting two random parts.
That makes perfect sense.

The Shop

4One7
Posts
67
Joined
12/6/2016
Location
Parkton, NC US
Fantasy
2538th
4/21/2022 6:10pm
From personal experience on a 05 YZ125. Put a hole in the left side case from a clutch push rod issue. Replaced just one half. This was done approximately 40hrs ago, no issues. You should be fine by just replacing one side.
1
Braaap728
Posts
2
Joined
4/21/2022
Location
Woodland, CA US
4/21/2022 6:23pm
I have replaced quite a few case halves in my life and never had an issue, and also why they sell them as halves and not one "kit"
lostboy819
Posts
11516
Joined
8/16/2006
Location
Somewhere, CO US
Fantasy
1342nd
4/21/2022 6:54pm
lwtracer wrote:
nearly all case sides are matched together from the factory. If the holes on each side are not line up perfectly you will destroy crank/crank bearings/transmission...
nearly all case sides are matched together from the factory.

If the holes on each side are not line up perfectly you will destroy crank/crank bearings/transmission bearings and the cases again.

if you have the missing piece, just get it welded.
wrong
4DAIVIPAI2K5
Posts
922
Joined
12/15/2016
Location
Coshocton, OH US
4/21/2022 7:00pm
lwtracer wrote:
nearly all case sides are matched together from the factory. If the holes on each side are not line up perfectly you will destroy crank/crank bearings/transmission...
nearly all case sides are matched together from the factory.

If the holes on each side are not line up perfectly you will destroy crank/crank bearings/transmission bearings and the cases again.

if you have the missing piece, just get it welded.
Husky only sells as a set for the 65, as they are match bored.
2
40acres
Posts
624
Joined
7/23/2017
Location
Houston, TX US
4/21/2022 7:08pm
Husky only sells as a set for the 65, as they are match bored.
The OP has a yz125, manufactured by a company by the name of Yamaha.
8
1
rhummel628
Posts
32
Joined
9/27/2018
Location
Sparks, NV US
4/21/2022 7:28pm
Not sure if Yamaha does it, but I replaced a left case on my cr250 last year and it came with new bearings already in it. Saved me a little money since I only had to order bearings for 1 side.
brocster
Posts
3610
Joined
6/9/2009
Location
Aliso Viejo, CA US
4/21/2022 8:29pm
Have done it many times, no issues.

Engineering, Quality Assurance, and quality control should rank very high at any of the major brands I would think. i.e. I don’t think they are just hap hazardly producing individual case halves that don’t match up.
lostboy819
Posts
11516
Joined
8/16/2006
Location
Somewhere, CO US
Fantasy
1342nd
4/21/2022 8:52pm
Husky only sells as a set for the 65, as they are match bored.
If my grandmother had wheels she would be a bicycle.
1
CraigCrashes
Posts
215
Joined
8/13/2020
Location
Sacramento, CA US
Fantasy
1665th
4/21/2022 9:41pm
Can’t speak on a YZ125, but I replaced only one side of my KLX110 cases and it’s been going strong since 2009 lol.
sandman768
Posts
6095
Joined
3/21/2014
Location
Saratoga Springs, NY US
4/22/2022 4:25am
You can match them for surfaces when you get the other case 1/2, I have done this many times. Just bolt them together empty, with case dowl pins installed, tighten case bolts. Now inspect all mating surfaces, base gasket, intake tract, ect. to make sure everything matches.
mx317
Posts
4560
Joined
4/1/2008
Location
TN US
4/22/2022 5:28am
Yamaha sells just one case half.
CPR
Posts
4385
Joined
10/4/2018
Location
AU
4/23/2022 2:28am Edited Date/Time 4/23/2022 1:42pm
Next time you have a two stroke bottom end apart, sit them together and look into the crankcase and see how well they’re matched; there’s your answer, they’re not. Not a problem buying YZ125 cases separately.
WEAL
Posts
169
Joined
11/6/2018
Location
DE
4/23/2022 12:48pm
Yamaha sent me both halves when a recall on 450 rh crankcases was happening. I was curious and compared old/new halves - the cylinderbase height was not the same. So they knew that for a proper repair both halves are needed. If only replacing one half I would at least measure the positions of all the bearings to avoid trouble later. Nothing destroys a bearing faster than any amount of offset. Of course you could be lucky and everything matches but in the long run the other half is probably way cheaper than missing a couple rides and having to tear the whole thing apart again and need a couple more parts which the misalignment destroyed ...
1

Post a reply to: Buying one case half?

The Latest