Saving a '81 KZ750-E

The case cover for the countershaft sprocket was really hard to clean. After getting 90% of the crap off the inside, i decided to put it in my bucket of Evapo Rust even though it's aluminum. I wasn't sure how it would do with old chain lube and road grime. 48 hour soak, water rinse. Wow! Didn't expect it to come out this clean...

The "mottled" appearance from oxidation on the outside surface doesn't go away with glass bead blasting. This pic shows how the pattern is still in the aluminum surface. I could blast it for 30 minutes without any further visible change. The important improvement is the texture of the surface. Very uniform and a great surface for paint adhesion.

220 grit sandpaper on a palm sized DA works good to buzz off the corrosion. After that I move to a sisal pad and black polishing compound. Use gloves because the part will get hot. Before you go though all that consider finding a newer model cover with a ramp and ball clutch actuator. It's smoother than that helix jobby you have now.

I am going to run with the parts I have. The helix thingy is working as designed after cleaning, greasing, and reassembly.

The last of the engine covers got 3 coats of paint today. I will sand back the text to aluminum after a couple days of drying time.

I've been out of town since Sunday morning, so the paint has had three days to cure. First thing I did when I got back in my shop was to sand back the text on the alternator cover. So far the paint adhesion is holding up nicely.

worth the wait

And another couple of weeks or so have slipped by without touching the bike. Time for this trend to change! Today I am disassembling the painted engine in preparation for final assembly. I do have an out of state trip planned for later this month, but until that happens I can focus on the motor. I am going to order up some A.P.E. cylinder head nuts to go with the studs I bought. Any insight on whether the washers that go under the head nuts should remain stock, or get aftermarket to go with the A.P.E. parts?

Cleaned off my weld table and covered with thick single layer cardboard. Disassembled the motor, and getting ready to start the next round of cleaning and inspection.

The clutch cover did not come out very well since the corrosion caused some pitting. After the semigloss black paint I am not happy with it. So it will go back in the blast cabinet for stripping. I will probably end up with some type of filler for the pitting, and repaint it after sanding it smooth.

Starting the assembly process. I found some threaded holes behind the transmission on the lower case half. I can't find any clear pictures of that area during disassembly (thought I took enough). I have scoured the shop manual, and no clear pictures or mention of what they are for that I can tell. Any ideas from you KZ750 guys? Maybe I am over thinking it? You see them to the left of the shift fork shaft in the floor of the case, next to the oil filter.

Have a look at exploded view of kickstart assy and you will see what they are for.

24 25 26.

If those two threaded holes are for a kick starter, this year and model did not come with one. That would explain why I can't find anything that goes there. Thank you, Mc Tavish!