Noob, just getting started on a 67 CL77

WrenchRust · Post by **WrenchRust** » Fri Aug 20, 2010 8:24 am

Jensen,

when I get home tonight I'll take some pics and post them. Is there anything or place in perticular where I should point the camera?

Joel

jensen · Post by **jensen** » Fri Aug 20, 2010 8:53 am

Hi,

Piston skirts seen from aside, inside of the cylinder bore seen in an angle from above.
Like these pictures from my CB400F rebuild :

jensen

WrenchRust · Post by **WrenchRust** » Sat Aug 21, 2010 7:29 pm

I haven't forgotten about the pictures. I've been working 14 to 16 hour days. Haven't done much. I did do a quick scrub down on the valves. Afterward I put some degreaser in the receases and let it sit. It seeped through the intake valves and I got a little moisture on the left exhaust valve. I put a flat head screw driver and worked them back and forth. The intake valves leaked less but still seeped. Same with the exhaust valve. I was going to pull the valves off and lap them but spring compressor was the wrong kind. I get tomorrow off and I'll try to steal some time with the bike.

Any words on doing the valves? Should I try to adjust them first? (0.004??) How do I know where top dead center is?

Joel

WrenchRust · Post by **WrenchRust** » Mon Aug 23, 2010 1:53 pm

Here's some pictures, sorry if the pics are big. not sure how to make them smaller...

WrenchRust · Post by **WrenchRust** » Mon Aug 23, 2010 1:54 pm

WrenchRust · Post by **WrenchRust** » Mon Aug 23, 2010 1:55 pm

jensen · Post by **jensen** » Mon Aug 23, 2010 3:25 pm

Hi,

Now, this are pictures indeed. It shows a few things, starting with the pins. Don't bother re-using these piston pins, they are burned. What bothers me is that one of the pins did turn around in the piston itself, it shows wear at the outside.

The cylinder bores are not fine, rebore and hone. You see the hone structure clearly in the underside of the bore, but in the area were the piston rings were, this structure is gone. This could be regular wear, but I think the rings did not have enough end play. Did you check the slot play of the piston rings before assembly ? Furthermore I see lot's of oxidation (rust) in the walls, this is due to condensation of the wall when the engine stands still. Maybe next time when you're planning not to ride it for a while, put oil into the plug holes (a few cc's) and kick it a few times, and repeat once a month.

Both pistons are in bad shape, especially in the area where the pressure between the piston and cylinder wall is big.

Find some new pistons, rings and pins. rebore the cylinders, hone them, check your small end (con-rods) with a new pin, and check your oil pump (just precaution).

Jensen