Back in the Saddle - New (to me) Motorcycle

[Fenixgoon]

After selling my Ninja1000 many years ago, a friend convinced me to get back into riding. I told him if he could find a bike in good condition for $2k, I'd buy it. Enter: a super clean 1980 Honda CB750 Custom. Not quite mint condition, but looks amazing for a 43 year old bike. Fires right up, just gotta do the basic maintenance to get it on the road.

 

[[DHT]Osiris]

After selling my Ninja1000 many years ago, a friend convinced me to get back into riding. I told him if he could find a bike in good condition for $2k, I'd buy it. Enter: a super clean 1980 Honda CB750 Custom. Not quite mint condition, but looks amazing for a 43 year old bike. Fires right up, just gotta do the basic maintenance to get it on the road.

Not my style (and I'll likely never own one) but I can acknowledge something pretty when I see it, esp what most would consider to be vintage. Great find!

 

[sdifox]

Can I have your stuff?

 

[repoman0]

That looks fantastic. If the roads near me weren’t crowded with texting aggressive morons I’d get back in the saddle too ..

 

[Fenixgoon]

Everything was literally perfect about the bike. I come back a week later, and nothing works right. Talk about frustrating.

Oil pressure light? Doesn't show
Neutral indicator light? Doesn't show
Clutch lever switch - always on
Turn signals? Don't work properly
Run/Kill-Switch - always on (the kill switch doesn't kill)
Clutch lever - doesn't fully disengage the clutch

I drove the bike around the block and things worked fine enough - the clutch lever disengages things enough, but it engages super far out into lever release.

But electrically speaking? Shit seems to have hit the fan....

 

[rstrohkirch]

So you ended up buying a super clean project bike =]

 

[Fenixgoon]

i've isolated the issue to the headlight circuit. when i pulled the fuse for that, the turns signals worked properly (front + rear). so, there's a short somewhere. i just hope it's an easy fix and not "redo part of the harness". granted, a 1980's motorcycle has a lot less wiring to it than a modern bike or car

 

[pauldun170]

My first bike was an 83' CB750SC. You are making me reminisce a bit

 

[rstrohkirch]

i've isolated the issue to the headlight circuit. when i pulled the fuse for that, the turns signals worked properly (front + rear). so, there's a short somewhere. i just hope it's an easy fix and not "redo part of the harness". granted, a 1980's motorcycle has a lot less wiring to it than a modern bike or car

The wiring harnesses on those older bikes aren't particularly hard to replace. If you find that you keep running into issues, consider just buying clean used one to save time. Hopefully it's just a couple of easy to solve issues.

 

[Toastedlightly]

See if you have the right bulb. Had a weird issue like that with an older Volvo and a single element bulb had been installed where a dual element was needed.

Sent from my Pixel 6 using Tapatalk

 

[Fenixgoon]

See if you have the right bulb. Had a weird issue like that with an older Volvo and a single element bulb had been installed where a dual element was needed.

Sent from my Pixel 6 using Tapatalk

Turned out to be a grounding issue.

The old headlight housing got grounded directly, and that (electrically) connected to the turn signals by the headlight mounting bolts.

So, I just had to add some ground wires to the mounting bolts, since the new housing is not directly grounded (just the led light itself).

So I took the bike out and everything worked perfectly fine.
Until I got back and the float overflow tube starting dripping gas. Hopefully it's just a stick float that will resolve itself.

I also have an issue with the oil pressure and neutral indicator lights, but those are just indicators.

Outside of those items, the bike pulled strong. Granted I didn't go past 5000rpm - it's been a while since I've had the option to go to 9000