cb 125 do i need to machine my cases?

H

hoonda

New Member
hi guys long time reader first time first time poster i have a old 73ish cb125 i got in bits
im doing a slow rebuild with a hint of cafe
i pulled the motor last week due to next to no compression and found a big hole in the top of my piston (thatl do it)
anyway i bought myself one of these, should arrive next week

http://www.ebay.com/itm/Honda-Cylinder-Bore-56-5mm-CB125-CL-XL-SL125-124CM3-New-/180714824640?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item2a137163c0

just wondering if anyones had experience with similar kits if so do i need to machine my cases?
auction is a bit vauge on demensions

thanks in advance

Hoonda
 
You will know when you get it whether it fits or not, eh?

Your engine will be badly contaminated with crap from the engine failure. Best strategy would be to split the cases for a complete tear-down and inspection of the bottom end.

Just as important, a piston getting holed is an abnormal kind of failure. It's usually caused by installing a pod filter without re-jetting. Not only does an engine run like shit after installing pod filter(s) without re-jetting, it runs so lean that it WILL cause engine damage. Once you get the engine back to running condition, you MUST resolve why it holed the piston, or it will just do it again.
 
First line in the description says that no machining is required... As was stated above, you'll need to pull that motor down completely before installing anything though. Clean THOROUGHLY. Clean everything three times if need be. You'd be amazed at how much damage a tine but of metal can do to a tight tolerance, small engine like the 125.
 
yea it says cylinder does not require machining?

motor was purchased of a bucket racer with 100 lil hondas no idea what was he running have ordered a full gasket kit and have started tear down and cleaning doesnt look toooo bad oil was pretty shetty.
il be running the standard airbox plug and carb settings to start with this would be my best beT??

maybe he was running a hotter plug? reckon that could cause it?
 
If it was a real race bike than there could be a million things wrong/modified/messed with. No way to know for sure unless the builder tells you or you start measuring everything.
 
Plan on running the airbox on that bike permanently. Those little guys HATE pod filters.
 
The line also says:
Nickel silicon carbide plated for long life. Honed to exact size for easy piston installation
Click to expand...

NiSil plating is done on Aluminum cylinders, not steel lined. The aluminum is cast with silcon carbide in the aluminum. A nickel electrode is used to etch the aluminum aay on the cylinder surface which leaves a layer of silicon carbide. Silicon Carbide is very hard material. Wears forever. The cylinders are not honed with this process. It would remove the silicon Carbide. This process was pioneered by GM (the Vega) but was done poorly. Mercedes licenses the process from GM and their engines all use this process nowadays.

..Makes me wonder about the accuracy of the information in the posting.

In addition, this is not a real Honda Part, but a Chinese clone part. It may work fine, but I would be suspect about the quality. I wouldn't assume the machining is right. It would pay to measure it before assembly.
 
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