CB125 valve clearances/ how to remove a cam chain?

[the95th]

I need to remove and replace the Head Gasket, as its leaking like a chocolate teapot, ive got the new gaskets, and i just cant figure out how to remove the cam chain, I unfortunately lost/destroyed my Haynes manual, and I cant find anywere on the BCF or google as to how to remove it, and what the Valve Clearances should be.

Also how do you tell if the Cam Chain is shagged to bits and needs replacing? and can you replace the auto adjust?

Ill also, do a full oil change on the bike, and clean out the oil strainer'mebob.

I seem to be only getting about 30mpg, filled up 20 quid... and only did 120 miles and top speed in 5th gear at 11000 is only 63/65, its probably due to the loss in compression, and a slightly leaking carb on the left side. Should go away after i put a new carb gasket in right?

Thanks guys
____________________
2004 Rieju Rs2 Matrix 50cc, 1982 Honda CG125, 1986 Honda Cm125, 1982 Honda Cb125..... I kill a lot of 125's

[stinkwheel]

Presuming this is a twin, not a single (65mph would be pretty good for a single, not bad for a twin to be honest)?

Undo the tensioner and take the tensioner blades out.

Now undo the bolts that hold the cam sprocket to the cam (don't drop them!) They can be really tight.

Slide the cam sprocket sideways off the cam. You should now be able to move the cam enough to remove the bushes off each end of the cam.

Now tie the camchain to the frame using a bit of wire loosely looped through it.

You should now be able to pull the camchain off the sprocket then slide the cam out from the middle and remove the sprocket.

Loss of compression due to a leaking gasket could well drop the speed and economy. I'd have a look at the valve seats while you're in there and consider lapping them in again as well as decoking the head if necessary.

Valve clearances are very small. 0.05mm (0.002").

Can't find a wear limit for the camchain so you're just going to have to eyeball it. if it looks worn or seems loose when you wiggle the links, replace it. The tensioner blades should have at least half the original rubber left on them and none should be peeling off the metal.

The autoadjust doesn't, never did do. Or at least not to an adequate degree. Loosen the nut at the back of the engine, press down on top of the tensioner blade and nip up the nut while still pressing down. Do this periodically.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[hornetmike]

Don't think you need to take the cain out, just let off the tension, remove cam or sprocket.
____________________
87 Honda CG 125 - 97 ER5 - SR 50 -81 Z250- 96 CBR 600 F- 94 GPX600R 88- GPX 400R- 87 GS 125 - 2006 Honda CB600F- 2003 ER5 - Honda CBF 1000 2009 - Honda CBR 600 RR 2011
Current BMW R1200GS 2010

[the95th]

thanks A lot =) , its a twin, 1982 Honda CB 125 TDC.
____________________
2004 Rieju Rs2 Matrix 50cc, 1982 Honda CG125, 1986 Honda Cm125, 1982 Honda Cb125..... I kill a lot of 125's

[lozza59]

hi just after the clearances for my cb 125 twin it a 1984
so