Re: New member from the STL. 1981 CB750C

Posted by djpj on
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/New-member-from-the-STL-1981-CB750C-tp4060432p4060515.html

Update:

Wiring all made up for the coil relay. I determined that the best position is going to be by the battery. Under the tank would let the relay get too hot and it might short out. I found the operating temp range for these things is around 185*F so above the air-cooled engine is a no-go.

Wires:
Black = negative from relay, 10 gauge
Red with fuse = power to relay, 10 gauge
Brown = From one of the blk/whte trigger wires on the coil, 14 gauge
Green = From relay to coils, split to go to both coils, 14 gauge
http://imgur.com/8iC2o5F
http://imgur.com/lejepCS
http://imgur.com/w0Rpn3o

Ran the wires alongside the original wiring harness and shrink wrapped like a doomsday prepper. (Excessive? I'm the one riding the bike so I'll be the one stuck somewhere if it's not perfect)

http://imgur.com/u6RoKlH
http://imgur.com/LqPKNyD
http://imgur.com/sLecgfh
http://imgur.com/9MmcxLH
http://imgur.com/rYaLqNF
http://imgur.com/RvkOeYz

Grounded at the airbox to frame mount. Received a strong ground there so I'm happy with it. I can still loosen it a little and move the airbox to get at the carbs.

Next I connected all the wiring to my relay and the battery.. POOF. Blew the inline fuse. Then, I checked and rechecked all the connections but I was still getting a current running through the inline fuse without the bike running. I pulled the relay and tested the ohms from the power to the ground without any other wires connected. Got a positive connection reading so I guess my Amazon relay is trash. I then went up to the local auto store and got another, tested it, and we are good to go again.

http://imgur.com/ZqeII2u
http://imgur.com/9JQaKYy

Test fire was a great success. It fired up quicker than my sport bike. Tested all the plugs and they are firing evenly. Then I proceeded to shrink wrap every connection and grease up any spots that could be susceptible to some water. Once again three layers of varying sizes of shrink wrap will hold it together until Skynet comes for us all. I might even add some more to the green wires connected to the coils.

Out of focus: http://imgur.com/zez0Pas

Test fire again and it's all good. I like to test after every little stage so I don't get too far along and realize that after 5 steps my bike won't run. Now it's onto the carbs:

http://imgur.com/iKCozGW
http://imgur.com/6uKMB3T
http://imgur.com/cVN00nr

Labeled every connection and took some pictures. I broke one vent hose and I'll replace both when I reassemble. Next step is to clean those dirty dirty carbs. I'll also use this time to get some degreaser on that engine and rinse it off, after I close up all the holes of course.


PJ