1972 CB500 with a 81' CB650

[Fueldrum]

Greetings!

First off, thanks for this great forum. What a wealth of information!

Bought my first motorcycle after riding vintage Vespa's for years. Saw this beauty on the local Craigslist and felt compelled to go pick it up.

It's a 1972 Honda CB500 that has been mildly customized to a vintage sport bike. It has been upgraded with a 1981 CB650 motor and electrical system including electronic ignition.

The seller did the following to it: new Jardine mufflers, new plugs and ignition wires, rebuilt forks, new battery, custom seat, custom tail light, new tires, rebuilt top end, rebuilt carburetors, new "California Orange" automotive paint, new fuel lines and filter, rebuilt front brake caliper and master cylinder, cleaned gas tank.

Issues it's still got that I need to fix:
Engine starts and runs but begins to cut out over 5000 rpm. Not sure if it is a jetting issue or ignition related.
Engine has some oil leaks.
Gauges work but tach needle bounces around over 3500 rpm and the odometer/trip meter do not work. Got an extra set of operational gauges with the bike.
No turn signal or mirrors are installed, kinda debating doing that, looks cleaner without them.

Came titled. Biggest issue in my mind is the 5000 rpm bog, gotta do some more research on that and see if I can nail it down. Engine is a tight fit in the CB500 frame, so that'll make it a little more difficult to work on, but feels great weight wise. Can't wait to get out and really ride it!

[Volker_P]

Welcome here!

Really great job. I like it!

For the bog down, feel at the headers if all four get equally hot. Also check carb boots for an air leak. As these are 81 carbs, try to bypass the vacuum shutoff, possibly it works not really as it should.

Jumping tach/speedo needles are often related to cables close to failure. Check out and use the opportunity to lubricate all cables. Sometimes needle has contact to the cover, have a close look.

Engine has some oil leaks.

Congratulations! This means it is a genuine CB650 engine so noone cheated you!

[wingman]

Not sure about where you are but aren't signal lights and mirror required?
I do agree that is pretty sweet like it is though.

[Fueldrum]

Welcome here!

Really great job. I like it!

For the bog down, feel at the headers if all four get equally hot. Also check carb boots for an air leak. As these are 81 carbs, try to bypass the vacuum shutoff, possibly it works not really as it should.

Jumping tach/speedo needles are often related to cables close to failure. Check out and use the opportunity to lubricate all cables. Sometimes needle has contact to the cover, have a close look.

Engine has some oil leaks.

Congratulations! This means it is a genuine CB650 engine so noone cheated you!

Headers felt equally hot, but I'll check them again to be sure.

Where's the vacuum shutoff on these carbs?

Weirdness, the tach cable is full on disconnected...but the tach gauge still jumps around when you rev the engine. I think it's just a bad gauge, I'm going to swap it out with a known good one the bike came with.

As for oil leaks, that was kinda my thought too! 30-year old engine, I'd almost be disappointed if it DIDN'T have some oil leaks...

Thanks for such a great forum!

[Fueldrum]

Not sure about where you are but aren't signal lights and mirror required?
I do agree that is pretty sweet like it is though.

Well, to be 100% sure I still need to read the letter of the law, but I've had several people tell me that in Kansas, the law reads something along the lines of "If it has turn signals, they must work"....so if it doesn't...they don't have to work...

Still need to check for sure, but dats what da man on da street says!

[Volker_P]

Vacuum shutoff sits on top of carbs three and four (right side). The part with the many small in/out hoses. May be removed completely, so might not be there any more, though.

One may check the tach "offline" with a drilling machine.
In case you like to have a look into the tach, here is a link how to open it without real damage: http://www.salocal.com/sohc/tech/speedo/spedo1.htm

[wingman]

Not sure about where you are but aren't signal lights and mirror required?
I do agree that is pretty sweet like it is though.

Well, to be 100% sure I still need to read the letter of the law, but I've had several people tell me that in Kansas, the law reads something along the lines of "If it has turn signals, they must work"....so if it doesn't...they don't have to work...

Still need to check for sure, but dats what da man on da street says!

Nice if you can keep it as is. Also what is the object mounted just left of the idiot lights? A switch?

[Volker_P]

From diameter, this looks like a 12V plug connector with chromed cover.

Proven tuning accessoire to drive a fan to simulate higher topspeed at least in your face.

[wingman]

What will they think of next?

[Fueldrum]

Not sure about where you are but aren't signal lights and mirror required?
I do agree that is pretty sweet like it is though.

Well, to be 100% sure I still need to read the letter of the law, but I've had several people tell me that in Kansas, the law reads something along the lines of "If it has turn signals, they must work"....so if it doesn't...they don't have to work...

Still need to check for sure, but dats what da man on da street says!

Nice if you can keep it as is. Also what is the object mounted just left of the idiot lights? A switch?

Actually, that's my ignition key spot. This bike is a total Frankenstein, the controls are off the CB650, but the idiot lights are off the CB500, so a new key had to be mounted.

[cb650]

Did u use the 650 charging and electrics? Looks good

[Custom81]

That bike is SHARP!!!

Do you know what that tail light is or where to get one? I want!

Very nice bike

[Ouch]

+1....this bike is clean....+1

[Fueldrum]

Did u use the 650 charging and electrics? Looks good

Correct, 650 electrical harness and controls, so it's got electric start, not kick. The handlebars are a bit of a Frankenstein as the controls are 650, but the idiot lights are 500, but the rest of the bike is a Frankenstein as well, so it just kinda works.

Fighting an oil leak at the moment, but she rides like a dream.

[wingman]

Hey I didn't recognize your name before. Hope the new pieces work out for you. Love your bike.