nateweisiger02
CB750 Enthusiast
I am going to go in depth to give as much info as possibly to help diagnose because I am totally stumped. Problem: Engine will turn all the way with screwdriver and about 50 lbs of force on the crank, but kickstart will not turn the engine over. Back story: This is a 1978 cb750 that was sitting for about 15 years so it was seized when I got it. After a lot of Marvel's, got it free and drove it around for about 30 total minutes.The bike slowly started losing power so checked compression. Compression was under 120 on all cylinders and 30 psi on cylinder 2. Broke into the engine and found that the rings were stuck, cracked intake valve on cylinder 2 (explained such low compression) and leaking head gaskets. I would like to add, did not hone or oil the cylinders, really really wishing I had but this was a first time for me and heard it wasn’t totally necessary (lesson learned). Split the case after replacing the rings, pistons 1,3, and 4 slid in fine. Cylinder 2 a little tight but would move with some force. Put the engine back together just fine but crank has been hard to turn. Let marvels sit in the spark plug holes, a little bit of Lucas, more Marvel, still the same. Put engine back in bike thinking it would work with the kickstart, nope. The kickstart will only move if pressure is on it and a screwdriver through the crank turning. So pistons are not seized, crank will move but with force. Does anybody have any type of clue what went wrong or what would cause this? Possibly not honing? I didn't figure that not honing would require me to put this much force on the crank. Sorry for the long post, just wanted to make sure I covered every single base and not leave anything out. Thank you to anyone who got through the whole thing!
