Valve problems! HELP!

CALfeRacer

CALfeRacer

Fat man on a little bike
I tore in to the engine on my 79 CB125 last night, and stumbled upon a problem: my intake valve is stuck open. The bike sat for some time without a carburetor, so there was some junk sitting on the valve and on the piston. I cleaned as much of it off as i could, and the valve is still stuck. I completely tore the head down, and am trying to figure out how to un-stick the valve. I have tried putting some fuel system cleaner in the intake port and leaving it around the valve, but that isnt helping. I have tapped on both sides of the valve with a mallet, and nothing. I need to get this bad boy un-stuck so I can put the engine back to gether and finish this build! Thanks for any help!!
 
CALfeRacer said:
I'm not sure. how would I be able to tell?
Click to expand...

Once you get the valve out, put it into a drill chuck and spin it. It'll be pretty apparent if the circles are not concentric.
 
On the note of taking the valve out.. I don;t have the honda valve spring compressor thing. What can I use as something to compress the spring so I can get the cotter off?
Thanks!
 
first things first , free up the valve .
into the oven it goes . something less than 300 degrees any more and the guide may move in the head.
on removal apply candle wax to the area between the valve stem and the guide .
if the valve does not move repeat the process until it does .
apply a bit of careful hammer force and it will eventually move .

~kop
 
1: it would be cheaper to get a new (used) head, after removing the valve, you'll need to replace the guide and valve, then have the seat and valve recut, that costs bucks and there's not much sense throwing money at it when used parts are so cheap
2: if there was debris on top of the piston, there's likely going to be rust on the cylinder and rings, this is something you need to check for, there's no sense throwing an engine together if its not going to work well
 
I got the head back from the shop today, and the valve seat is gone. So, problem is according to the guy in the shop, there isn't anywhere around here where I can get work done on it, since it is so small. I'm considering swapping a XR200 head on it. Any input on this?? If it's a bolt on, what I need, etc. I had the piston out, and the cylinder and rings all look good, no rust or anything.
 
just go buy this

http://www.ebay.com/itm/HONDA-CB125-CB-125-SL125-SL-CL125-CL-ENGINE-HEAD-VALVES-MOTOR-/310671288230?pt=Motorcycles_Parts_Accessories&hash=item485573a7a6&vxp=mtr

like, now...

there's an art to knowing when to give up and just buy a replacement... I'm not good at it, but you might turn out to be
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light

    • Spread the Love

    Back
    Top Bottom