PDA

View Full Version : Please help!! CR125 engine rebuild



JeremyW
10th June 2007, 18:38
Well I am in the unenvious position of trying to find a cylinder head to fit my CR125. I have found out that getting one new is next to impossible so I must get one second hand.

See my problem is that the bike is approximately 1000 years old (well a 1988, but it might as well be!) and I cannot seem to find anything for love nor money. I ran the engine dry (don't ask!) and the head has a lot of pitting, enough that I have been told it is not possible to just face off. I would like to get a new head but I need to find out what is going to fit.

So, does anyone know much about the CR125 engines from 1987 to 1991? If so I would love to pick your brains about what parts match what because knowing the range of years that would fit would make my life a lot easier.

T.W.R
10th June 2007, 18:42
Here's a cheapy on TM :yes:

http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Parts-accessories/Engine-drive-train/auction-103382897.htm

JeremyW
10th June 2007, 19:23
Thanks, I had a look at that but the rest of the engine is in good condition (cylinder just honed, new piston among other stuff) so its just a head I need.

Sketchy_Racer
10th June 2007, 19:25
whats wrong with the current head?

JeremyW
10th June 2007, 19:34
It has really terrible pitting in one section, it has completely erroded the lip which I was told is needed for gasket sealing (???). I can get it welded and faced off but it wont be nearly as strong and I would rather try and get a new (or better) one.

What is the usual process for 2 smoke engines? Do they normally get repaired or replaced when they are damaged?

Brian d marge
10th June 2007, 20:14
Look at the middle part numbers of the head should be something like Kz7 this is the model it was first used on

Dont worry about detting it welded and refaced they are a high silicon aluminum low( er) yield strength

I have a parts book for the 91 bike but not for any other years

( on the 250s the big changes were in 85/86 when they went from the Atack to the hpp engine)

I have a few spares for a 96 cr if you get stuck
Stephen

JeremyW
10th June 2007, 20:31
Awesome, thanks I will have a look. So if I wanted to find out if a 90 head would fit I could look at the part number and see if it is the same or corresponds to a head from an earlier engine?

JeremyW
10th June 2007, 20:32
Dont worry about detting it welded and refaced they are a high silicon aluminum low( er) yield strength


Do you mean dont bother getting it welded or dont worry about it as it is ok to do it?

Brian d marge
10th June 2007, 20:51
Without seeing it , it should be ok to weld , and re machine , but the cost of that may be more than buying a secondhand head

I am in the office now so cant get the parts book

but see how you go sourcing a second head

Stephen

JeremyW
10th June 2007, 21:01
Sweet, thanks for the advice :niceone:

xwhatsit
10th June 2007, 22:31
Well I am in the unenvious position of trying to find a cylinder head to fit my CR125. I have found out that getting one new is next to impossible so I must get one second hand.

See my problem is that the bike is approximately 1000 years old (well a 1988, but it might as well be!) and I cannot seem to find anything for love nor money. I ran the engine dry (don't ask!) and the head has a lot of pitting, enough that I have been told it is not possible to just face off. I would like to get a new head but I need to find out what is going to fit.

So, does anyone know much about the CR125 engines from 1987 to 1991? If so I would love to pick your brains about what parts match what because knowing the range of years that would fit would make my life a lot easier.

<hints id="hah_hints"></hints>Anybody with an old shitty Honda they need parts for needs only to know this name: http://www.econohonda.co.nz . Massive amount of parts, exceedingly cheap, and Malcolm is a top bloke. Fast shipping up here to Auckland, too.

Have fun.