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Showing posts with label head. Show all posts
Showing posts with label head. Show all posts

Monday, May 9, 2011

CT 70 Head and Valve Teardown

Big boy takes off the tappet caps.


The right side cover comes off with screws, since the long bolt is already gone.





If you look really close you can see the threads inside rocker arm pins.




I forgot the thread pitch, but at this point plenty of bolts are laying around. The footpeg mount bolt fits.




Screw it in and pull it.







Okay, I should have pulled the tappet adjuster screw and lock nut, before the rocker arm pin, but it still comes apart okay.







Now the valve spring compressor.








When the spring pressure is off, then the keepers come out.







Here's the exhaust valve components. I need to check all the free lengths on these springs, to see if I can re-use them.




Exhaust valve is dirty, but seems reuseable. I'll see how they lap out.







The pad on the rocker is terrible. I'll need a new one.




There's a collar one and seal the exhaust side only.




Bag and tag.




On to the intake side, here's the rocker arm pin.




Intake rocker is smoked, too.




Cam falls out.




Seems good enough to be re-used.








Here's the intake valve guide. It doesn't take the collar and seal, like the exhaust.




Exhaust valve guide.




Exhaust valve seems to be useable.





Thursday, April 7, 2011

Trail 70 Clean up

The full teardown is coming, so let's get the engine cleaned and ready to come out. Dump the oil. Take off the sparkplug guard. A nut in the middle, one on the shock tower, and two on the exhaust studs and the exhaust comes off.



Four bolts up top and two under the engine and the big brush guard comes off.




Now to the power washer. It worked pretty good, but it wasn't picking up the soap right.



We got most of the red mud and oil off of the engine, but we couldn't get the bottom to clean up real well. I tried some foaming degreaser and it didn't do it either. Check out this exhaust port. I thought it was broken and I would need a new head, but actually that is normal for the CT70's. I had to ask about it on the lilhonda.com board to verify it though.



Now that it is relatively clean, I plan on building a stand for the bike and a stand for engine for rebuild. I am also planning on breaking all the torques on the screws, bolts, and nuts, before I pull the engine out of the frame.