cr 125 trouble!!

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Jun 11, 2010

• #26

Keep it on the plating as much as possible. Rinse off the aluminum or it will darken the metal if left on too long. Put it on with a q-tip or small paint brush. The exhaust bridge is a good holding spot for aluminum! Read the cautions on the can, no really.

 

L

lake

Member

Oct 30, 2008

45

0

• Jun 18, 2010

• Thread starter
• #27

I was just messing around today and stuck an old piston and ring in my cylinder, and it looked like there was more of a gap between the piston and the cylinder on the exhaust port side. Am I going to have to send my cylinder away to be sleeved?

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Jun 19, 2010

• #28

There very well could be an issue with the bore. Sleeving is 1 option. Its questionably cheaper at first, and definitely not in the long run. You can get it re-plated is the best option in my opinion, and the pistons, you get what you pay for. Send Eric your top end and he will fix it. At this point, he may well be able to get you the best price on a complete engine rebuild kit, including the crank or rebuild the old one. Typically a complete kit is around 350, fixing the cylinder another 250, give or take a hundred?

 

L

lake

Member

Oct 30, 2008

45

0

• Jun 19, 2010

• Thread starter
• #29

The crank is already at a shop now being put back together.

I'll give forward motion a call to see what they can do for me.

I also put just the ring in the cylinder and then shined a flash light up through the bottom, i could see light in two places where there are small digs in the cylinder, i'm in the process of trying to get the digs out with emery cloth but it's not going to well.

 

S

sr5bidder

Member

Oct 27, 2008

1,463

0

• Jun 19, 2010

• #30

you really shouldnt be doing that....

does the machine shop that doing your crank have a nice hone? that may work ..but eyeballing it with emory paper is not a good idea

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Jun 19, 2010

• #31

The scotch pad was for getting the flashing off. Dings, like a groove not all the way through the plating, is likely through the plating. Some platings are a thousandth or 2, some are less.

 

L

lake

Member

Oct 30, 2008

45

0

• Jun 20, 2010

• Thread starter
• #32

Is there anyway i can tell if it went throught the plating or not? I was just trying to get the spots out a bit where i could see light through the ring.

 

L

lake

Member

Oct 30, 2008

45

0

• Jun 24, 2010

• Thread starter
• #33

Since my old head was plained and i'm bought a brand new one, am I going to have to order some jets and rejet the it?

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Jun 24, 2010

• #34

Until we get efi bikes, we jet them manually, yes. If its plated, that gouge went through it. If its a sleeve, then it would need to be bored to clear up the .015" gouge? Rubbing it out will insure there is an area that is .015" out of round.

 

F

FNG

Member

May 2, 2008

97

0

• Jun 25, 2010

• #35

lake said:

Since my old head was plained and i'm bought a brand new one, am I going to have to order some jets and rejet the it?

Click to expand...

Most likely yes but also verify what is in the carb now and then compare to what the stock settings are. If you have a pipe call them and see what they recommend for it. If it is ported call them etc...

Every bike can and should be jetted to run "right". The manufacturers jet them safe for the consumer, and to protect themselves.

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Jun 25, 2010

• #36

Everything effects your jetting, and that includes the weather at the top of the list. Even if you had 2 brand new identical bikes, they will require specific jetting for each, and will be different. And that means jetted properly/crisp. To me, a bike that is not jetted crisp, is very unsafe to ride, even for an old guy not going big anymore. Vintage Bob