85 FZ750N will crank... Occasionally

[fz7]

Hi guys, I'm FZ7 and I own an 85 Yamaha FZ750N. I've been working on this thing for years on and off, but never really completed it.

Anyway, without further adeu, my problem is that this bike cranks the engine occasionally. One day I thought I fixed the problem, and the next day it doesn't work and now it still doesn't. I have read the manual troubleshooting section and here are the problems listed:

a)Blown fuse

b)Discharged battery

c)Sidestand or clutch swithc malfunction

d)Engine stop switch malfunction

e)Defective starter motor button

f)Defective starter motor

g)Seized pistons

h)Seized crankshaft bearings

i)Broken connecting rod

Of these problems I think only c, d, and e apply to me. Reasons:

a)Blown fuse - (checked fuse, works fine)

b )Discharged battery - (Even though it's been left out, I charged it before I started working on it)

c)Sidestand or clutch switch malfunction - (I checked this one already, but maybe it's messed up again? I might have to double check this one again)

d)Engine stop switch malfunction

e)Defective starter motor button

f)Defective starter motor - (Opened up the motor unit and rebuilt it. I also tested it by connecting a jumper wire from the battery to the power terminal)

g)Seized pistons - (When I bought the bike, it was actually running even though it has many problems)

h)Seized crankshaft bearings - (Same reason as above)

i)Broken connecting rod - (ditto with above)

So definitively, this leaves c,d, and e. Now can anyone tell me how to test for these, as the manual is a bit hard to understand and the pictures are terrible quality too. Any input however, is appreciated.

Thanks guys.